Documents published in 2019 : Scipedia

UV laser processing in reparison task of monolotithic laminate of carbon fibre elements. Influence of processing direction
M. Botana-Galvín, J. Botana, L. Utrera, R. Páez

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 59

Abstract
In aeronautical sector, the step of removing damaged fabrics included in the process of reparison of carbon fibre elements is performed via manual grinding. This procces is few automatable and shows high level of dificulty in depth control of removed material. Owing to the trend to procceses automation, different automatable technologies are being studied as alternatives that enable to obtaing higher control of this process. This work studies the use of an UV laser system to perform this task. This technologies led to a salective and controlled revomal of fabrics by the control of processing paramenters. Firstly, values of power, processing speed and frequency have been optimised in order to obtain an acceptable rermoved material amount to time ratio. Furthermore, the influence of fibre relative orientation with respect to processing direction on the amount of removed material has been studied. For that purpose, unidirectional tape samples have been laser processed with different processing direction, and the amount of removed material for all of them has been measured. Once optimized the processing direction, the number of shadows required to remove one entire fabric has been determined. Processing conditions that enable to remove selectivley and controlled fabrics of composite material have been determined. This would allow to automate the process of removing fabrics included in bonded breparison of elements of carbon fibre.
Abstract
In aeronautical sector, the step of removing damaged fabrics included in the process of reparison of carbon fibre elements is performed via manual grinding. This procces [...]
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UV laser surace activation in co-bonding of CFRP elements. Comparison with other certified methods
M. Botana-Galvín, F. Botana, R. Páez, F. Serrano

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 58

Abstract
There is an increasing trend towards the substitution of mechanical joining by adhesive bonding in carbon fibre elements (CFRP) in aeronautical sector. However, it is mandatory to perform a previous step of surface preparation in order to obtain the best adhesive properties to the surface. There are some certified superficial preparation methods by the aeronautical sector, being shot peening, grinding and peel-ply the most used ones. All of them have the disadvantage of not being automatable. Hence, new potentially automatable methods for surface activation are being studied. In this work it has been studied the use of UV laser radiation as a surface activation method previous to adhesive bonding, and its behaviour has been compared to peel-ply activated samples. To this end, an advanced surface characterization has been performed, by means of surface free energy determination, surface chemical composition determination by XPS measurement, surface roughness and morphology observation with SEM. Mode I fracture toughness test have been performed for all surface activation methods. The obtained results show that adhesive bonding of UV laser treated samples have mode I fracture toughness comparable values to those obtained for peel-ply and peel-ply plus grinding samples. Furthermore, all the failure modes observed are accepted by the sector normative. This makes that UV laser surface preparation could be considered as an alternative for certified surface method of CFRPs.
Abstract
There is an increasing trend towards the substitution of mechanical joining by adhesive bonding in carbon fibre elements (CFRP) in aeronautical sector. However, it is mandatory [...]
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Smart behaviour of CNT modified adhesive films for carbon fiber composite repair
C. García-Nieto, X. Sánchez-Romate, M. Sanchez, A. Ureña

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 57

Abstract
Epoxy adhesives films were doped by spraying an aqueous dispersion of carbon nanotubes. Sensing capability of carbon fiber reinforced composite coupons with bonded patch repairs was evaluated; several single lap shear and Mode-I fracture energy tests were conducted and their electrical responses were characterized. It was observed that electrical resistance increases with mechanical strain due to tunnelling effect on CNT percolating networks and increases of electrical resistance associated to crack propagations could be also detected. Once the smart behaviour if the adhesive joints was identified by means of mechanical tests in normalized adhesive joined specimens, panels (400 x 400mm) with square co-bonded patches, made using the same curing cycle based on the repaired material one, were prepared using CNT doped adhesive films. These panels were mechanical tested to determine the effect of the doping treatment on the mechanical behaviour of the repairs, at the same time that electric measurements were carried out to identified local failures during testing. Obtained results showed that structural film adhesives could be surface doped with CNT providing sensing capabilities to be used in structural health monitoring of adhesive repairs in composite structures.
Abstract
Epoxy adhesives films were doped by spraying an aqueous dispersion of carbon nanotubes. Sensing capability of carbon fiber reinforced composite coupons with bonded patch repairs [...]
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Application of functionally graded adhesives in aluminium-composite joints
A. Chiminelli, R. Breto, M. Lizaranzu, E. Duvivier, M. Laspalas, S. Lafuente

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 56

Abstract
Adhesive joints are characterized by non-uniform distribution of stresses and strains along the bond-lines, with maximum values near the ends of the overlaps. This phenomenon can cause the premature failure of the joints, being specially critical when brittle or semi-brittle structural adhesives are considered. This has motivated the research in the field of ‘functionally graded adhesive’ (FGA) or ‘multiple-adhesive’ joints, which reduce the phenomena described through a combination of rigid and brittle adhesives with more flexible and ductile ones. In this way, these strategies allow to notably increase the joints maximum load capacity. In this field, this article presents the work carried out by ITAINNOVA within the project SAFEJOINT. Specifically, the potential of the techniques based on ‘banded’ gradings as approximations of the continuum gradings is analysed. The study is focused in aluminium-composite single lap shear (SLS) joints with epoxy adhesives. The work done covers both the numerical optimisation of the joints and the fabrication and testing of samples in order to verify experimentally the potential for improvement of the technique comparing with mono-adhesive joints. Finally, an example of application of the technology is presented.
Abstract
Adhesive joints are characterized by non-uniform distribution of stresses and strains along the bond-lines, with maximum values near the ends of the overlaps. This phenomenon [...]
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Bonding of composite parts: advantages and benefits of Structural Adhesives and Self-adhesive Tapes
H. García, F. Ballesteros

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 55

Abstract
The bonding process of composite materials is a challenging method in growing markets like Transportation and Construction. Differents methods exist today for the assembly of composite materials: mechanical fixing, ultrasonic welding, structural adhesives and acrylic foam tapes. Each method has its own advantages and drawbacks, but bonding with structural adhesives or acrylic foam tapes offer important benefits compared to mechanical assemblies. Adhesives and tapes allow to bond dissimilar substrates while keeping mechanical performance and improving aesthetics of composite materials. The Transportation market is leading the increasing demand of composite materials and design engineers look for detailed information on bonding methods and the performance of adhesives for the designed vehicles: mechanical and vibrations resistance, tenacity and elasticity, durability and capability to withstand extreme conditions. Design engineers require more than a bonding solution, they need technology partners like 3M providing technical support for project development, materials and adhesives testing, and process consultants for the optimization and automation of bonding processes. Los ingenieros quieren algo más que una solución adhesiva, y buscan socios tecnológicos como 3M. The purpose of this article is to create awareness on 3M new adhesive and tape technologies for multi-material bonding integrating a composite material. Assembly types and solutions allow to find the best adhesive technology for optimal bond design and manufacturing process.
Abstract
The bonding process of composite materials is a challenging method in growing markets like Transportation and Construction. Differents methods exist today for the assembly [...]
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Experimental evaluation of the quality of a composite-composite adhesive joint by peeling tests
M. Castro, J. Cañas, G. Santacruz, J. Justo, A. Cañas

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 54

Abstract
The evaluation of the quality of composite-composite bonded joints is a major problem for the aeronautical sector given by the fact that a defective joint not only could paralyze the productive process, but it could also involve very high restoration costs. Currently, the quality of the bond is quantified by an interlaminar fracture toughness test. This test measures GIC in a test piece that is bonded theoretically under the same conditions as the actual piece. The measurement of GIC is performed by the DCB test or by the Drum Peel test. Both tests cannot be carried out on the actual part or "in situ". The present article shows a device that carries out the peeling test on the real part allowing to obtain results comparable to those that could be obtained with the traditional procedures of DCB and Drum Peel. In order to verify the validity of the new device that has been designed, an experimental campaign has been carried out to test non-symmetrical composite-composite laminates with different techniques, by comparing the different GIC values obtained. A numerical study carried out in another paper confirms that the evaluation of GIC obtained with the experimental results is adequate.
Abstract
The evaluation of the quality of composite-composite bonded joints is a major problem for the aeronautical sector given by the fact that a defective joint not only could paralyze [...]
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Analysis of the behaviour of adhesive composite repairs subjected to static loads
L. Fernández-Cañadas, I. Iváñez, S. Sánchez-Saez

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 53

Abstract
Aircraft structural components made of composite materials are susceptible of being damaged during their service life. The high level of integration and large size of these structural components may make very difficult the replacement of damaged parts; thus, repair damaged components is a solution that can save economic and temporal costs. Adhesively-bonded repairs offer certain advantages when compared to mechanical repairs, therefore there is an increasing interest in the study of their mechanical response to static loads, and a detailed structural analysis depend on several parameters. In this work, a finite-element numerical model was developed in Abaqus/Explicit commercial code. The model was validated experimentally. The numerical model was used to analyse the mechanical response of patch repaired laminates subjected to tensile static loads. The effect of the repair patch shape (rectangular or circular) and repair patch size on the failure load and elastic stiffness was evaluated by carrying out a series of virtual tests using the validated numerical model.
Abstract
Aircraft structural components made of composite materials are susceptible of being damaged during their service life. The high level of integration and large size of these [...]
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Out of autoclave bonded repair process and implementation for aircraft composite structures
I. Nieto-León, A. Rodríguez-Bellido, M. Múñoz-López

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 52

Abstract
With the entry into service of aircrafts with a very high percentage of composite materials the necessity of efficient repairs for such structures arises. Airbus has developed an out of autoclave bonded repair process for highly loaded composite primary structures of the A350XWB. It can be used at production plants but also in the in-service operation of the aircraft. Bonded repairs eliminate the requirement of rivets in carbon fibre parts allowing flush repairs that complies with the original component functionality and requirements. The repair process includes removing the damaged plies by successive milling steps, each one equal to a single ply thickness. The repair technique consists on the application of a soft patch with specific repair materials, different from those involved in the manufacturing process and with the unique characteristic of curing at low temperature in out of autoclave conditions. The aforesaid facilitates application in plenty of circumstances and scenarios. This paper describes the coordinated investigation performed in order to provide a robust and sound out of autoclave repair system and process. The combination of feasibility trials in actual repair conditions and material characterization tests proved to be essential to understand the critical steps and to optimize the process performance.
Abstract
With the entry into service of aircrafts with a very high percentage of composite materials the necessity of efficient repairs for such structures arises. Airbus has developed [...]
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Design of adhesive-bonded structure solutions, contribution of the modelling of the adhesive
I. Retolaza, N. Corujo, M. Areitioaurtena, A. Cenitagoya, I. Zulaika, M. Canellada

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 51

Abstract
Finite element modelling of adhesive joints has been analysed in this work, applying the results and conclusions of the design process of a multi-material base of an elevator. The main approach of the study has been the modelling of the adhesive joint, different parameters and its application in complex models. For that purpose, a case study has been carried out in a simply supported plate model. Several modelling techniques have been analysed and design recommendations have been proposed. Characterization of composite materials and adhesives has also been studied, given the fact that the anisotropy of the composites is an additional difficulty in the Finite Element Analysis. Having the real properties of these materials is a very important factor for efectiveness in terms of economical and computational cost. The correlation of simulation and experimental results has been analysed in the practical case study and the contribution of the adhesive modelling has been studied. To conclude, the importance of the material characterization and the sensitiveness to the variation of their properties are to be mentioned. The work offers the designer several recommendations on adhesive joint modelling as well as parameters that might affect the analysis of a structure that contains adhesive bonding.
Abstract
Finite element modelling of adhesive joints has been analysed in this work, applying the results and conclusions of the design process of a multi-material base of an elevator. [...]
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Study of alternative materials for Portland cement replacement in civil construction
M. Moraes, J. Moraes, M. Tashima, J. Akasaki

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 50

Abstract
The proposal of this work is to study materials, which initially were classified as disposable, in building construction as new alternative materials. In this way, this research studied the partial replacement of Portland cement in mortars by the following pozzolans: sugar cane bagasse ash (SCBA), rice husk ash (RHA), metakaolin (MK) and silica fume (SA). Theses composites were compared with a control mixture, which no Portland cement replacement, in the following tests: compressive strength, consistency, water capillarity and water immersion. The replacements percentages carried out were 5, 10, 15, 20, 25 and 30% for SCBA, RHA and metakaolin, and 5, 10 and 15% for silica fume by weight. The compressive strength test was performed at curing times of 3, 7, 28 and 90 days, whereas water capillarity and water immersion were carried out at 28 days. In the early ages, few mixtures showed resistance above the reference, but with 90 days, six mixtures passed the control. All mixtures with pozzolans presented less water absorption by immersion and capillarity. Sustainably, the use of SCBA, RHA, MK and SA is viable.
Abstract
The proposal of this work is to study materials, which initially were classified as disposable, in building construction as new alternative materials. In this way, this research [...]
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Design and development of an innovative structural system based on composites applied on the constrction of maritme lighthouses with lower maintenance requeriments (FAROCOMP)
S. Hernández, N. Uranga, E. Martinez, M. Sanchez, A. Martín, J. Sacristan, P. Sánchez, J. Jiménez, S. Primi, E. Navarro

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 49

Abstract
The overall objective of the project was to develop a structure based entirely on polymer matrix composite materials intended for use as a sea lighthouse. This project was developed as part of the works corresponding to the North expansion of the Port of Valencia promoted by the Port Authority of Valencia. The work carried out covered both the definition and execution of the structural design and calculation strategy as well as the development and characterization of the materials and the different manufacturing processes employed, as well as the strategy of assembly and installation of the structure in its final location. Throughout the project an optimum cost / performance ratio was maintained, fulfilling the specific requirements of the structure and the pertinent regulations.
Abstract
The overall objective of the project was to develop a structure based entirely on polymer matrix composite materials intended for use as a sea lighthouse. This project was [...]
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Characterization of the CRTM process applicated to a door reinforcement
U. Argarate, E. Arregi, G. Acosta, M. Baskaran, J. Aurrekoetxea, L. Aretxabaleta

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 48

Abstract
The automotive industry has benefited to some extent from composites for several decades, especially for non-primary structural applications. Technologies such as GMT, LFT or SMC are used to manufacture interior components, functional parts or body parts, with productivity standards and very competitive prices. But despite these successful applications, their expansion to more structural parts is not possible because of the limited properties of the materials and largely because the current manufacturing processes and facilities are not ready for mass manufacturing. When it is intended to manufacture pieces with high fiber contents and / or large pieces, the increase in fiber content decreases the permeability of the preform, necessitating longer filling times, and generating impregnation problems and high pore contents. In order to solve these drawbacks associated with conventional RTM, different alternatives have been explored: increasing the injection pressure, injecting through multiple entries or reducing the viscosity of the resin among others. One of the most promising is the combination of RTM and compression, called CRTM (Compression RTM). Comparing with conventional RTM, the mold remains partially open in the injection phase, generating a space not occupied by the fibers that exerts a preferred flow path for the resin without having to penetrate the preform. The objective of the project has been to characterize the CRTM process and apply this knowledge in the manufacture of a side door reinforcement.
Abstract
The automotive industry has benefited to some extent from composites for several decades, especially for non-primary structural applications. Technologies such as GMT, LFT [...]
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Design of 3D printed cores to improve radial compression behaviour of pultruded composite tubes
A. Esnaola, I. Saenz-Dominguez, I. Tena, M. Iragi, U. Morales, L. Aretxabaleta, J. Aurrekoetxea

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 47

Abstract
E-glass/vinylester composite crash structures manufactured by ultraviolet (UV) pultrusion process have shown high values of especific energy absorption (SEA). However, comparing the radial compression behaviour of the tubular structures with the axial crushing behaviour, it has been noticed that the stiffness and the strength of the structures to radial compression is too low. In order to improve the radial compression behaviour of the structures manufactured by UV pultrusion, different cores have been designed and manufactured by 3D printing using FDM (Fused Deposition Modeling) technology. On the one hand, an hexagonal core consit on a thin external skin made with ABS and filled with 3D printing support material has been analyzed. Otherwise, an hexagonal core designed following the honeycomb concept has been printed and tested. The composite structures with the cores have been tested in radial compression in quasi-static conditions and they have shown higher stiffness and strengh due to the 3D printed internal cores. The composite structure with the hexagonal ABS skin core and support material has improved the stiffness of the composite tubular structure 9 times while the strength has increased 5 times. In the case of the honecomb ABS core, the stiffness of the structure has increased from 1.15 kN/mm to 22 kN/mm (19 times more). Meanwhile, the strenght values using the ABS honeycomb core has been 17 times higher than the empty composite structure.
Abstract
E-glass/vinylester composite crash structures manufactured by ultraviolet (UV) pultrusion process have shown high values of especific energy absorption (SEA). However, comparing [...]
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Thermoplastic composite penetration in the aerospace structures
F. Rodríguez-Lence, E. Lorenzo, K. Fernández, S. Romero, M. Zuazo

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 46

Abstract
FIDAMC(Fundación para la Investigación, Desarrollo y Aplicación de Materiales Compuestos) , has been investigating different technologies, under the frame of several research projects funded by Clean Sky initiatives and Spanish governmental entities, in order to demonstrate that thermoplastic can be directly manufactured via automation without autoclave consolidation and the full integration of the structure by co-consolidation method fusing together the skin and stringers in only one melting step. Our Center is currently involved in an interesting project with a complete manufacturing solution of a thermoplastic wing skin using Automatic Fiber Placement (AFP) with assisted laser system as heating source techniques. This new Out-of-Autoclave procedure will be validated with ground/flying tests in 2020. This paper provides an overview of several research projects aimed to develop the automated lamination and in-situ co-consolidation technology and includes a review of automated methods to lay up PEEK prepreg from the first AFP head, in cooperation with the Spanish supplier MTORRES and installed six years ago in FIDAMC, the evolution of this machine and the up-to-the minute configuration of new Multi-tows head to produce the feasibility demonstrator panel with co-consolidated "T" shaped stringers and scale up the methods to the final stiffened wing panel to incorporate in Clean Sky 2 as Flight test Bed developed by Airbus.
Abstract
FIDAMC(Fundación para la Investigación, Desarrollo y Aplicación de Materiales Compuestos) , has been investigating different technologies, under [...]
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Use of composite materials in aerodinamic seals
G. Morales, M. Puig

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 45

Abstract
This paper describes the use of composite materials in the manufacture of aerodynamic seals. Specifically, the design of the seals between the wing and the belly fairing, made by ALESTIS AEROSPACE, is reviewed for the A350 XWB.In the process, FEM simulations and tests have been performed to obtain the levels of stifness required by the aerodynamic specifications. These tests are made to find the right balance between stifness and adaptability of the seals to the wing geometry, and compliance with the boundary conditions imposed by the pressure difference between the interior of the belly fairing and the exterior (static and dynamic pressure ). Due to the variation of seal boundary conditions, both pressure levels and displacements to be absorbed, in addition to the life requirements, the materials used provide different degrees of rigidity: Matrix: silicone Reinforcements: Polyester fabric Fiberglass fabric Glass composite material Matrix: polyester resin Reinforcement: glass fabric Finish: polyester fabric with low friction treatment The use of suitable combinations of materials allows for lighter and more efficient seals.
Abstract
This paper describes the use of composite materials in the manufacture of aerodynamic seals. Specifically, the design of the seals between the wing and the belly fairing, [...]
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Manufacturing of complex parts based on unidirectional tapes. Technology transfer from automotive towards aeronautic industry
A. Tielas, R. Ledo, V. Ventosinos, D. García

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 44

Abstract
CTAG, together with FORTAPE1 partners, developed an optimized and more efficient system for the manufacturing of parts with complex geometries, based on the use of thermoplatic tapes reinforced with unidirectional fibres (glass and carbon fibre) for its use in the automotive and aeronautical sectors. The effors were focused on the process automation, which enables to obtain high production volumes, and on the material and energy consumption, allowing a considerable weight and cost reduction on the final component. Moreover, CTAG is partnering AEROCAR2 consortium, a project that has started in the third quarter of 2016 and that aims to create a technology transfer network between the automotive and aeronautic sector. The final purpose is to imporve the productivity through the creation of new technologies, materials and/or processes to put into value the synergies between the concerned sectors. The principal challenges to be faced in collaboration with companies and technology centres are the use of new materials and the process automation.
Abstract
CTAG, together with FORTAPE1 partners, developed an optimized and more efficient system for the manufacturing of parts with complex geometries, based on the use of thermoplatic [...]
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Manufacture of a suspension subframe through CAPROCAST technology (T-RTM)
A. Calle, S. García-Arrieta, C. Elizetxea, I. López

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 43

Abstract
The main objective of this work has been the manufacture , and subsequent flexural and fatigue tests, of automotive real parts, made of thermoplastic composites. This has been achieved by incorporation continuous carbon fiber (textile) to polyamide matrix, through an specific process very similar to a thermoplastic RTM. The fatigue behaviour of any composite is governed by the toughness of the material. Because of this and the low cost, the polyamide has been considered as a polymer matrix. The process involves an in-situ polymerization, that the low viscosity of the monomer,e-caprolactama (e-CL), allows the infiltration of preforms and textiles. The demonstration part has been completely redesigned by BATZ and TECNALIA to fullfill mechanical requirements and manufacture ability. In particular, it has been fabricated a suspension subframe with an 52%vol. of a commercial carbon fiber and thickness variations from 3 to 8mm within the same part, obtaining a significant reduction in weight relative to the metal part (6,8 kg vs 3,48 kg) and the established mechanical requirements. As far as the fatigue/durability test are concerned, they have been performed to evaluate the strength of the composite and to increase the correlation between CAE analysis and the real behavior of the hybrid component. All the tested parts support 2.000.000 cycles (the stipulated for this part in metal) without break, only with small deformations in the bushings holes. As far as the flexural test are concerned, they evaluate the maximum quasi-static strength of the component. All the parts tested deform considerably, recovering much of this deformation once the load is removed.
Abstract
The main objective of this work has been the manufacture , and subsequent flexural and fatigue tests, of automotive real parts, made of thermoplastic composites. This [...]
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Methodology for wishbone manufacturing for a F1 ar based on carbon fiber
I. Jáuregui, A. Tellez, M. Siqueiros, B. González, S. King

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 42

Abstract
The following article proposes a methodology for the creation of a fork of a single-seater of formula 1 with composite material of bidirectional carbon fiber and epoxy resin in a laminate of 6 layers with angles [90, -45, + 45] having as aim a fork with a faster and less expensive process compared to those used in the world of formula 1.
Abstract
The following article proposes a methodology for the creation of a fork of a single-seater of formula 1 with composite material of bidirectional carbon fiber and epoxy resin [...]
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Mechanical characterization and validation of biocomposites in small ship hull construction. Life Cycle Assessment.
A. Lopez-Arraiza, F. Valencia, G. López, A. Bermúdez, C. Montoya, J. Ramón

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 2 - Aplicaciones, uniones y reparaciones de los materiales compuestos), 41

Abstract
Nowadays, glass fiber reinforced polyester laminates are widely used in manufacturing small ship hulls by hand lay-up. The main drawbacks of the use of these composite materials are: the dependence of hydrocarbons on the synthesis of resins, the high energy cost to obtain glass fiber and the emission of volatile harmful compounds in the manufacturing process. In this work, the advantages of using flax fiber reinforced bioresins are analyzed. Tensile and flexural standard tests were performanced. After that, a small craft of less than 24 meters in length is designed in accordance with the international norm ISO 12215-5. The results indicate that despite the need for greater thickness, the total weight of the vessel is reduced by 12% using biocomposites. Besides, Finite Element Analysis (FEM) indicates that the structural design can be clearly optimizated. Finally, Life Cycle Assessment (LCA) reveals an environmental improvement of the boat made of biocomposite instead of glass fiber. However, this improvement is limited by land occupation and the high water footprint of flax fiber in its production process.
Abstract
Nowadays, glass fiber reinforced polyester laminates are widely used in manufacturing small ship hulls by hand lay-up. The main drawbacks of the use of these composite materials [...]
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Development of Titanium Matrix Composites for Aerospace applications
M. Lagos, I. Agote, G. Atxaga, X. Hernández, C. Jiménez, L. Pambaguian

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 40

Abstract
Titanium Matrix Composites are very interesting for aerospace applications. These materials typically present higher Young Modulus and resistance than conventional titanium alloys. The ceramic reinforcement can be continuous or discontinuous (fibers or particles). Main advantages of discontinuously reinforced TMCs are the isotropic mechanical properties and the lower production costs. This work presents the development of discontinuously reinforced TMCs with TiC as reinforced particles. The reinforcement was obtained by Combustion Synthesis and the final consolidation by Spark Plasma Sintering. Main advantage of this PM process is the short processing time. Regarding the thermos-mechanical characterization, the material presents higher stiffness and resistance with higher thermal conductivity than conventional Ti-6Al-4V. This work also presents the scale-up of the SPS process to obtain aerospace demonstrators. Machining and joining issues are also considered.
Abstract
Titanium Matrix Composites are very interesting for aerospace applications. These materials typically present higher Young Modulus and resistance than conventional titanium [...]
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Metallic composite material to protect against high-velocity projectiles and high energy impacts
R. Seddon, J. Maudes, A. Pérez-Márquez, N. Murillo, M. Herrán, J. Izaga, P. Venegas, I. Ocáriz, A. Fernández, J. Fuente

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 39

Abstract
The catastrophic failure of structures due to the impact of high energy waves or high speed projectiles can occur in a wide range of situations, including ballast impacts on high speed trains, manmade terrorist acts or accidental industrial events. High energy absorbing materials are therefore essential for the protection of both the hardware as well as personnel. One common requirement in all applications is the development of materials with reduced weight whilst guaranteeing high energy absorption levels. The aim of this work has been the investigation of lighter weight metallic composite systems with suitable properties aimed primarily at withstanding high-velocity projectiles and high energy impacts. (E≈ 100 J or v ≈ 120 m/s). Metallic hybrid test panels have been designed and manufactured using both aluminum and aluminum foam layers. To evaluate their efficiency in the case of a high energy impact the panels have been tested under simulated high-velocity projectile impact conditions by means of a pneumatic air cannon.. The tested panels have been assessed using visual inspection as well as X-ray tomography and IR thermography. The panel deformation as well as the delamination between structural layers has been assessed for the different proposed solutions.
Abstract
The catastrophic failure of structures due to the impact of high energy waves or high speed projectiles can occur in a wide range of situations, including ballast impacts [...]
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Development of a novel fabrication method to obtain Al/AlN composite
A. Riquelme, M. Escalera-Rodríguez, P. Rodrigo, J. Rams

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 38

Abstract
In situ metal matrix composites are novel composites for which the reinforcement is formed within the parent alloy by controlling chemical reactions during the composite fabrication. The aim of this research is to develop a novel methodology to manufacture good-quality in situ Al-AlN composites in a cost effective way. In situ Al-AlN composite powder was synthesized with laser equipment with a high power diode laser connected to a coaxial nozzle and projecting an aluminum powder in a N2 as carrying gas. The composite powder fabricated was characterized. Distribution of the projected particles temperature during the fabrication process was evaluated to identify the reaction mechanism. In all cases, the reaction mechanism is a surface type. Also, a relation between the particles temperature achieved during the fabrication process and the AlN atomic structure was analyzed. This composite powder can be directly deposited as coating on magnesium and aluminum alloys conventionally used in the automotive and aerospace industries or can be used to produce pulvimetallurgy composite materials.
Abstract
In situ metal matrix composites are novel composites for which the reinforcement is formed within the parent alloy by controlling chemical reactions during the composite fabrication. [...]
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Silanization treatment for improve adhesion in Al-PP surfaces
A. Valea, F. Juanes, M. Corcuera, V. Astigarraga, M. González

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 37

Abstract
In this work, a wide range of different silane based compounds has been studied with the aim of preparing the surfaces of the Al2024 and the polypropylene (PP). Afterwards, these materials have been joined with two kinds of adhesives: two-component structural adhesive DP8005 and double-sided adhesive tape RP45 (due to its interest in fast assembling operations). The compounds used for surface treatments are based on silane agents. Likewise, same authors have presented non-silane based treatments in other work (1). Both works, complement each other and provide the basis for a third one where the experimental design of measuring properties, mechanical properties in particular, is discussed (3).
Abstract
In this work, a wide range of different silane based compounds has been studied with the aim of preparing the surfaces of the Al2024 and the polypropylene (PP). Afterwards, [...]
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Chemical superficial treatments in Al2024 for improve the adhesion on polypropylene
A. Valea, J. Miguez, A. Eceiza, V. Astigarraga, M. González

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 36

Abstract
The joint of materials employing adhesives has been used for a long time. However, the possibility of generating joints between materials with remarkably dissimilar surface free energies, as in the case of joining metals and polymeric materials (with hydrophobic nature), is the main goal of this work and a novel area of investigation. In this work, a broad range of different compounds to prepare surfaces of Al2024 and polypropylene (PP) has been studied, in order to be joined subsequently by two kinds of adhesives: structural two-component adhesive DP8005 and double-sided adhesive tape RP45 (due to its interest in fast assembling operations). Surface treatments used in this work are based on non-silane compounds, in particular, two agents of maleinization (in solution), a nitrant agent at different concentrations, due to its behaviour depends on if it reacts as strong acid, oxidant agent or nitrant agent, following by a microwave treatment; a phosphating process; a glycidyl methacrylate treatment and, by a way of comparison, a conventional priming agent. The silane treatments are reported in other work (1).
Abstract
The joint of materials employing adhesives has been used for a long time. However, the possibility of generating joints between materials with remarkably dissimilar surface [...]
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Development of hydrofopic release agent by using SiO2 nanoparticles
I. Izarra, J. Cubillo, A. Gálvez, J. Rodríguez, M. Carmona

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 35

Abstract
This research group has developed a hydrophobic release agent using hydrophobic silica nanoparticles containing hydrophilic functional groups, which form hydrogen bonds with the water present in the fresh concrete and hydrophobic groups (CH3) that are distributed on the surface of the concrete providing hydrophobic properties to the surface. A vegetable oil was used as a support for the development of the release agent, using different types of nanoparticles and modifying the molar ratio between the precursors Methyltriethoxysilane (MTES) and Tetraethylethylsilicate (TEOS). Each release agent was used for the impregnation of standardized molds in the manufacture of concrete specimens. The hydrophobic properties of the test specimens were studied by measuring the contact angle of the water respect to the .It was observed that the best release agent was manufactured by using a nanosilica having a molar ratio of 2.5, which presents a contact angle higher than 145 º.
Abstract
This research group has developed a hydrophobic release agent using hydrophobic silica nanoparticles containing hydrophilic functional groups, which form hydrogen bonds with [...]
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Effect of the cross-linker content and type of graphene on the thermo-mechanical properties of nanocomposites
A. Toribio, C. Salom, M. Prolongo, A. Martínez-Martínez, S. Prolongo

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 34

Abstract
In this paper we study the influence of the type of graphene (GNP) and the different ratios of the crosslinking agent (XB)-resin epoxy (LY) on the thermo-mechanical properties of epoxy-graphene nanocomposites (GNP). Epoxy/GNP nanocomposites have been prepared using two different types of graphene: one non-functionalized (GNPn) and one amino functionalized graphene (GNPNH2). The content of graphene has been 6% and 10% by weight. The thermo-mechanical properties of the LY-XB thermoset and the nanocomposites have been determined through dynamic mechanical thermal analysis and tensile tests in a universal testing machine. The glass transition temperature and the storage modulus in the elastomeric zone (T>Tg) of the thermoset LY-XB and the nanocomposites have maximum values for slightly rich amine content. The addition of graphene significantly increases the elastic modulus of the nanocomposites compared to the neat epoxy thermoset (LY-XB), both in the vitreous region (T<Tg) and in the elastomeric region (T>Tg). The thermoset LY-XB shows the best strength and toughness for the stoichiometric ratio XB/LY. The addition of graphene leads to more rigid but more fragile materials.
Abstract
In this paper we study the influence of the type of graphene (GNP) and the different ratios of the crosslinking agent (XB)-resin epoxy (LY) on the thermo-mechanical properties [...]
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Curing of graphene-epoxy nanocomposites: influence of cross-linking / resin ratio
A. Toribio, M. Prolongo, C. Salom, A. Martínez-Martínez, S. Prolongo

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 33

Abstract
In the present work the influence of the graphene type (GNP) and the different crosslinking agent ratios in the curing of graphene-epoxy dispersions and in the glass transition temperature (Tg) of the formed nanocomposite is studied. The epoxy resin type DGEBA (LY) has been crosslinked with an aromatic polyamine (XB). Two types of graphene have been used: one non-functionalized (GNPn) and another functionalized with amino groups (GNPNH2). In the two systems, 5 compositions with different XB / LY ratios have been studied and, the content of graphene has been varied (6 and 10% by weight). The curing reaction has been studied by Differential Scanning Calorimetry. It has been observed that the presence of graphene accelerates the curing reaction and that the enthalpy of reaction depends on stoichiometry and graphene content. It has also been found that the variation of the Tg of the material with the stoichiometry, depends on the curing protocol.
Abstract
In the present work the influence of the graphene type (GNP) and the different crosslinking agent ratios in the curing of graphene-epoxy dispersions and in the glass transition [...]
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Graphene-Carbon Nanotubes Thermosetting Epoxy Materials: Water Absorption Influence on their Properties
C. Arribas, M. Prolongo, C. Salom, M. Sánchez-Cabezudo, R. Tirado, S. Prolongo

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 32

Abstract
This work presents the effect of hydrothermal aging in distilled water on several epoxy hybrid materials that have a certain amount of carbon nanotubes and/or graphene nanoplatelets. Two types of graphene nanoplatelets have been used: amino functionalized graphene (GNH2) and non functionalized graphene. When functionalized graphene is used, covalent bonds between the graphene nanoplatelets and the epoxy matrix are expected to be formed over the curing process. Non functionalized graphene platelets are used to prove this effect. Gravimetric study of the absorption process has been done as well as the effect of the water absorption on the thermo-mechanical properties and the electric conductivity.
Abstract
This work presents the effect of hydrothermal aging in distilled water on several epoxy hybrid materials that have a certain amount of carbon nanotubes and/or graphene [...]
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Graphene filled polyetheretherketone (PEEK) composites made by melt-compounding
A. Alvaredo, J. Fernández-Blázquez, P. Castell, R. Villoria

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 31

Abstract
In the present work, a graphene nanocomposite material using as matrix a high performance thermoplastic polymer (PEEK) is presented. Composite was made by a simple extrusion-compounding process, followed by an injection-moulding process. The main advantage of this process is that it could produce large quantities at the scales needed for use in industrial applications as structural applications. Nanocomposites with different percentages of graphene 0.5, 1, 3, 5 and 10 wt.% were characterized and compared with neat PEEK as baseline. The mechanical tests showed that the Young´s modulus increased when adding graphene while the strenght remained constant. In addition, a change in the failure mode was observed when the graphene was added. Nanocomposites with high contents of graphene had lower strain at break than neat PEEK.
Abstract
In the present work, a graphene nanocomposite material using as matrix a high performance thermoplastic polymer (PEEK) is presented. Composite was made by a simple extrusion-compounding [...]
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Improvement of the process of the direct synthesis of polyamide to obtain a high properties material
A. Calle, S. García-Arrieta, C. Elizetxea, I. Aranguren

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 30

Abstract
Under the NANOTEK+ project, POLIFLUOR and TECNALIA propose to develop and scale industrially a polyamide obtained by direct synthesis. These properties, mainly thermal ones, have to be improved by the addition of nanoparticles. To this end, it has been worked in the dispersión of the nanoparticles and the process of polymerization, and in the industrial production process and its evaluation from the point of view of the health security. In-situ polymerization process of anionic polyamide 6 offers important advantages for the incorporation of nanoparticles because the low viscosity of the monomer make easier the dispersion of the nanoscale reinforcemenet. Several parameters of the process have to be taken into account during the up scaling: Selection of the suitable nanoparticles and their percentage, taking into account the dispersion ability in the matrix and their chemical compatibility. Percentage of catalytic system, which can be affected by the nature of the nanoparticles. Melting, feeding and polymerization temperatures, which should not degrade the nanoparticle. Mixing rates, since the dispersion of the nanoparticles by mechanical stirring can produce air inside the obtaindes polymer. The distribution of the nanomaterial in the polymer matrix and the adhesion degree between both, have studied under formulated material, using techniques such as SEM/EDS. The correct distribution of the nanoparticles in the polyamide 6 has been observed thoughout the industrialization.
Abstract
Under the NANOTEK+ project, POLIFLUOR and TECNALIA propose to develop and scale industrially a polyamide obtained by direct synthesis. These properties, mainly thermal ones, [...]
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Bio-polyamide nanocomposites: influence of synthesis approach on final properties
M. Herrero, M. Asensio, K. Núñez, J. Merino, J. Pastor

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 29

Abstract
Bio-polyamide nanocomposites were prepared using the two most viable techniques from the industrial point of view: the melt intercalation process and in situ polymerization. The effect of the synthesis approach and the amount of nanofibre were evaluated in order to check their influence on morphological, thermal and mechanical properties. Regardless of the preparation method, all nanocomposites showed good despersion of nanoclay in polyamide matrix and significant improvements in Young modulus, tensile strenght and heat-distortion temperature were achieved. However, the nanocomposites obtained by in situ polymerization presented higher values since the dispersion of the nanoclay occurs during polymerization, when polymer chains are growing and the viscosity of the matrix is still low.
Abstract
Bio-polyamide nanocomposites were prepared using the two most viable techniques from the industrial point of view: the melt intercalation process and in situ polymerization. [...]
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Surface modification of sisal fibers to be used as a reinforcement in polypropylene composite materials
A. Valea, M. Corcuera, A. Eceiza, M. González

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 28

Abstract
Sisal fibers have taken special focus by material investigators and commercial environment because they are economical, biodegradable and lightweight(1). Composite manufactured using natural fibers can supply properties that can be compared to other composites reinforced with synthetic fibers, as previous studies have shown (2-6). Thus, fibers that come from nature sources, such as wood, nuts fruit, jute, kenaf, hemp, sisal, etc. are being introduced in composite manufacturing (7-9). Sisal fiber has relevant economical and ecological properties (10), but it is a lignocelulosycal fiber with hydrophylic character, so it is difficult its usage with hydrophobic matrix, and it is required to use coupling agents in order to improve its interface adhesion. This work starts with sisal fibers submitted to different types of primary treatments, and for each one of these treatments, sisal fibers are submitted to secondary treatments of maleinization, mercerization, silanization, formation of nascent surface isocyanates, carboxylation and methacrylate treatment. The efficiency of these treatments has been evaluated using morphology characterization techniques by FTIR-ATR, electronic microscopy (SEM). With some of the treated fibers, thermoplastic composites have been prepared and these have been used to prepare standard probes that have been thermally and mechanically tested, as well as other additional interesting physicochemical characteristics.
Abstract
Sisal fibers have taken special focus by material investigators and commercial environment because they are economical, biodegradable and lightweight(1). Composite manufactured [...]
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Characterization of cellulosic samples obtained from sisal fibers
A. Arbelaiz, G. Mondragon, I. Larraza, C. Peña-Rodriguez, A. Eceiza

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 27

Abstract
In this work the reaction conditions of different chemical treatments used for the isolation of nanocellulose were evaluated. This study clarified the effect of different reaction conditions (time or concentration) on the structure and composition of the cellulosic fibers, To achieve this objective, different chemical, thermal and morphological characterization techniques were used after each chemical treatment and the most suitable reaction conditions were selected.
Abstract
In this work the reaction conditions of different chemical treatments used for the isolation of nanocellulose were evaluated. This study clarified the effect of different [...]
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Bacteriostatic effect of waterborne polyurethane-urea films containing bioactive plant extracts incorporated by different routes
A. Santamaria-Echart, I. Fernandes, A. Arbelaiz, F. Barreiro, M. Corcuera, A. Eceiza

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 26

Abstract
The environmental awareness has promoted the development of new materials towards eco-friendly systems based on both, green synthesis processes as well as the renewable origin of the raw compounds. In this way, focusing on synthesis methods, the use of waterborne polyurethane-urea dispersions have gained attention due to their versatility leading to a wide variety of applications, broadening the range of applications. In addition, it is worth nothing that the dispersibility in water offers the possibility of incorporating soluble additives, such as plant extracts. Therefore, in this work Melissa officinalis L. plant was selected in order to obtain bioactive plant extract, in order to be incorporated to a waterborne polyurethane-urea dispersion, varying their content as well as using three different incorporation routes. These dispersions were characterized and employed in the preparation of films which were analyzed from the viewpoint of physicochemical, thermal and mechanical properties, among others. Finally, the antibacterial properties of the films were analyzed after 1 and 4 days of incubation, where it was observed that the content and incorporation route of the extract influenced in the behavior of the films against common pathogens (Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa).
Abstract
The environmental awareness has promoted the development of new materials towards eco-friendly systems based on both, green synthesis processes as well as the renewable origin [...]
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Study of blends based on poly (lactic acid) and vegetable oils
A. Orue, A. Eceiza, C. Peña-Rodriguez, A. Arbelaiz

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 25

Abstract
Due to the high brittleness of the poly (lactic acid) (PLA), the main purpose of this work is to obtain a more ductile material than neat PLA, and the subsequent characterization by different techniques. In order to plasticize neat PLA, some plasticizers from renewable resources, such as non-epoxidized and epoxidized and soybean oils, have been used. Neat PLA has been plasticized with 20 wt% of plasticizers and the properties of different blends have been studied. Impact test results have showed that PLA became more ductile with the addition of vegetable oils. Furthermore, PLA/epoxidized vegetable oil blends showed higher tensile and impact strength values than that for blends plasticized with non-epoxidized oils. Fourier transform infrared spectroscopy (FTIR) technique has showed that the band related to the epoxy group did not completely disappear in the spectra of PLA/epoxidized vegetal oil suggesting an incomplete reaction between the epoxy group of epoxidized vegetable oils and the functional groups of PLA. Finally, by differential scanning calorimetry (DSC) technique has observed that after the addition of vegetable oils, both the glass transition temperature (Tg) and the cold crystallization temperature (Tcc) values of the neat poly (lactic acid) were decreased considerably.
Abstract
Due to the high brittleness of the poly (lactic acid) (PLA), the main purpose of this work is to obtain a more ductile material than neat PLA, and the subsequent characterization [...]
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Bending in two planes of unidirectional composite laminates
N. Carbajal, F. Mujika

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 24

Abstract
In this work bending in two planes of long fiber composite laminates is proposed as a test method for knowing the behaviour of this material in case of combined loads. Different samples have been manufactured and tested using carbon/epoxy T6T/F593 material. Three cases have been considered dendending on the value of the ratio between normal stress in fiber direction and normal stress in direction perpendicular to fibre: less tan 1, equal to 1 and greater than 1. In all cases failure has been related to matrix failure, being a linear relation between stress and deformation until failure. Stress values have been analized by three failure criteria: Rankine, Tsai-Wu and maximum strain energy. Rankine criteria fits well the first two cases. The parameter of Tsai-Wu criteria between normal stresses in fiber direction and normal stresses in direction perpendicular to fibre has been obtained using experimental results. When stress in fiber direction is much greater than stress in direction perpendicular to fiber, this small stress can be ignored in the calculus of maximum strain energy.
Abstract
In this work bending in two planes of long fiber composite laminates is proposed as a test method for knowing the behaviour of this material in case of combined loads. Different [...]
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Experimental determination of the Weibull parameters in tensile failure using hybrid laminates
M. Cantera, G. Czél, M. Jalalvand, M. Wisnom

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 23

Abstract
Composites trend to failure in their defects, which are randomly distribuited. This causes that the tensile strength decreases when the volumen of material tested increases. This fenomenon is known as size effect or volume effect. Knowing the value of the Weibull parameters is key for modeling and the correct design of large components. In this work, one tensile test are proposed, named the fragmentation test to obtain the shape and scale Weibull parameters that are validated with the scaled test. Carbon/glass hybrid composites can exhibit pseudo-ductile response in the stress-strain curves by having a part with small slope or plateau. The specimen design promotes fragmentation or gradual fracture of carbon layer and suppresses unstable delamination at the plateau. The facture events have been identified by video and accoustic emission monitoring in 11 specimens. The data of fracture strain has been adjusted to the Weibull distribution following the proposed iterative process. The process has been validated using previous results of Finite Elements. The volumen effect has been validated with the results of series of tensile tests, with dimensions scaled by factors of 2,4 and 8 in each direction. Another important advantage of hybridization is the suppression of the stress concentration in the carbon layer, which makes simple end-tab free specimens feasible. The results of two tests have been compared, obtaining very close values.
Abstract
Composites trend to failure in their defects, which are randomly distribuited. This causes that the tensile strength decreases when the volumen of material tested increases. [...]
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New formulations for composites cured by ultraviolet radiation
I. Saenz-Dominguez, I. Tena, M. Sarrionandia, J. Torre, J. Aurrekoetxea

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 22

Abstract
In the present paper a resins comparative study has been carried out, focused in out of die ultraviolet (UV) cured pultrusion process. In this new approach of the traditional pultrusion, the profile is cured outside the die with UV radiation. This fact implies th necessity of working with resins that present fast curing kinetics at the first stage of conversion in order to avoid the expansion of the profile at the exit of the die. Thus, with the aim of developing new photocurable resin formulations, it has been analysed the curing kinetics of an unsaturated polyester, epoxy-acrilate and a mixture of both resins (50%) with the photocalorimetry technique. Moreover, physical properties test and quasi-static compression test have been performed of profiles manufactured by UV pultrusion. The results prove that the mixture of both resins increase the conversion rate of unsaturated polyester, due to the faster curing kinetics of epoxy-acrylate. However, this fact has not been reflected in the percentage of voids, more elevated in the profiles manufactured by epoxy-acrilate. Nevertheless, the mixture presents higher energy absortion (SEA) values, about 22% higher than the unsaturated polyester and approximately 15% higher than epoxy-acrilate.
Abstract
In the present paper a resins comparative study has been carried out, focused in out of die ultraviolet (UV) cured pultrusion process. In this new approach of the traditional [...]
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Prepreg, carbon fiber, thermoset autoadhesive resin for sandwich structures: advantages, disadvantages and manufacturing challenges
I. Mudarra, M. Acosta, C. C.Saleiro

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 21

Abstract
It’s thoroughly known that sandwich structures in aeronautical sector are formed by a core material, which more usual format is honeycomb, between two facings or skins made from several prepreg material layers. Nevertheless in order to obtain an adequate adherence between core and prepreg most of thermoset resin systems need the presence of a film adhesive placed among the core and prepreg to favour the adhesive menisci formation inside core cells. Main benefit asociate to autoadhesive prepregs usage in sandwich parts is adhesive elimination from part configuration which translates in a weight reduction of the structure. Present article is centered in autoadhesive prepreg materials 180º cure. After more than 3 years of work with several composite materials manufacturers and AIRBUS, key process parameters in an industrial environment have been defined along with basic characteristics in order to guarantee internal quality of the elements
Abstract
It’s thoroughly known that sandwich structures in aeronautical sector are formed by a core material, which more usual format is honeycomb, between two facings or skins [...]
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Effect of interleaved fiber mats on the manufacturability and mechanical properties of carbon/epoxy composites
J. Gayoso, I. Harismendy, J. Maudes, A. Pérez-Márquez, N. Murillo

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 20

Abstract
Fracture toughness is a critical property of composites, especially in the case of materials manufactured by liquid composite moulding processes because of the brittleness of the thermoset polymeric matrix. The use of thermoplastic interleaving veils can improve the fracture behaviour affecting only slightly other mechanical properties. Also, the veils can affect the manufacturability of the composites. This work presents a study of the influence of commercial and homemade veils on the manufacturability process and mechanical properties of carbon fibre reinforced composites. Results obtained show a significant improvement of fracture toughness without affecting manufactubarility.
Abstract
Fracture toughness is a critical property of composites, especially in the case of materials manufactured by liquid composite moulding processes because of the brittleness [...]
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Basic guidelines for choosing autoclave curing tool material to make composite parts. CFRP vs INVAR36
J. Galiana

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 19

Abstract
The correct selection of a curing tool, to make Carbon Fiber composite (CFRP) parts, is key to the success of a project. The trend in the Aeronautical industry is the reduction of costs and structural weights. The required curing tools are getting bigger and complex, which is a challenge for the manufacturers of the parts and tools. The high temperature autoclave curing cycles present a serious drawback to the use of conventional tooling materials, which has forced the development of molds made of materials with a low coefficient of thermal expansion to solve the problems arising from the different behavior of parts and molds during cycles and to ensure the tight geometric tolerances required. INVAR 36 and CFRP material with high performance resin have become standards for the manufacture of molds. The objective of the study is the comparison of properties and performance of this type of materials, as well as an estimation of the costs associated with each one, with the aim of helping the selection of the most appropriate for use in an industrial environment of high production rates. The method used consisted in the compilation of the technical characteristics of the materials that affect the performance of the tools, as well as the results of research projects and experience of the behavior in service. In addition, a simulation of costs associated with the development, manufacture, putting into production and maintenance of the molds was carried out. The results allow to evaluate qualitatively the performance of the molds manufactured with these materials as well as to have basic guidelines for the correct evaluation of them.
Abstract
The correct selection of a curing tool, to make Carbon Fiber composite (CFRP) parts, is key to the success of a project. The trend in the Aeronautical industry is the reduction [...]
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Effect of graphene nanoplatelets addition in benzoxazine carbon fiber laminates properties
V. García-Martínez, M. Gude, S. Calvo, A. Ureña

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 18

Abstract
In this work, the effect of graphene nanoplatelets (GNPs) addition in the mechanical, thermal and electrical properties of carbon fiber composites was studied. GNPs were incorporated into benzoxazine matrix and nanocomposites with a 0.5 and 2 wt.% of graphene nanoplatelets were manufactured. The effect of this nanoreinforcement in benzoxazine mechanical properties as well as in its thermal and electrical conductivity was evaluated. Carbon fiber composites has been manufactured by means of liquid resin infusion (LRI) technique using the nanocomposites prepared. The manufacturing process with the nanocomposite containing a 2 wt.% of GNPs presented some filtration problems which hindered its characterization. The laminate with a 0.5wt.% of nanoreinforcement showed an increase in both thermal and electrical conductiviy regading to the panel with unmodified benzoxazine.
Abstract
In this work, the effect of graphene nanoplatelets (GNPs) addition in the mechanical, thermal and electrical properties of carbon fiber composites was studied. GNPs were incorporated [...]
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Hierarchical Composite Materials
J. Vázquez-Moreno, R. Sánchez-Hidalgo, E. Sanz-Horcajo, J. Viña, R. Verdejo, M. Manchado

Materiales Compuestos (2019). Vol. 03 - Comunicaciones Matcomp17 (2019), (Núm. 1 - Materiales (2)), 17

Abstract
Conventional continuous fiber reinforced polymer composites (FRP) have extensively been used as structural elements in a myriad of sectors, such as civil, transport, energy and marine, among other, due to their superior mechanical properties, low weight and ease of processing. However, the relatively weak compression and interlaminar properties of these composites limit their application field. Interest is, therefore, growing in the development of hierarchical or multiscale composites, in which, a nanoscale filler reinforcement is utilized to alleviate the existing limitations associated with the matrix dominated properties. The majority of the work has focused on carbon nanotubes, CNTs due to their extraordinary intrinsic properties. In addition to their outstanding mechanical properties, CNTs possess excellent electrical and mechanical properties, making them attractive materials as reinforcement for polymer matrices. CNTs provide both intralaminar and interlaminar reinforcement, thus improving delamination resistance and through thickness properties, without compromising in-plane performance. In recent years, there has been an increasing interest in the use of graphene as reinforcement of polymer nanocomposites. Compared to CNTs, graphene has advantages such as lower cost, higher surface area and a greater ease of processing. Graphene is more easily dispersed in the resin and causes a lower viscosity increase, which can facilitate the impregnation of the fibers. In this work, the fabrication and characterization of hierarchical composites are analyzed through the inclusion of graphene to conventional continuous carbon fiber reinforced epoxy composites by vacuum-assisted resin transfer molding.
Abstract
Conventional continuous fiber reinforced polymer composites (FRP) have extensively been used as structural elements in a myriad of sectors, such as civil, transport, energy [...]
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Influence of User Preferences on the Revealed Utility Factor of Plug-In Hybrid Electric Vehicles
G. Tal, S. Raghavan

Collection of open articles in transport research (2019). Vol. 2019, 315

Abstract
Plug-in hybrid electric vehicles (PHEVs) are an effective intermediate vehicle technology option in the long-term transition pathway towards light-duty vehicle electrification. Their net environmental impact is evaluated using the performance metric Utility Factor (UF), which quantifies the fraction of vehicle miles traveled (VMT) on electricity. There are concerns about the gap between Environmental Protection Agency (EPA) sticker label and real-world UF due to the inability of test cycles to represent actual driving conditions and assumptions about their driving and charging differing from their actual usage patterns. Using multi-year longitudinal data from 153 PHEVs (11&ndash 53 miles all-electric range) in California, this paper systematically evaluates how observed driving and charging, energy consumption, and UF differs from sticker label expectations. Principal Components Analysis and regression model results indicated that UF of short-range PHEVs (less than 20-mile range) was lower than label expectations mainly due to higher annual VMT and high-speed driving. Long-distance travel and high-speed driving were the major reasons for the lower UF of longer-range PHEVs (at least 35-mile range) compared to label values. Enhancing charging infrastructure access at both home and away locations, and increasing the frequency of home charging, improves the UF of short-range and longer-range PHEVs respectively. Document type: Article
Abstract
Plug-in hybrid electric vehicles (PHEVs) are an effective intermediate vehicle technology option in the long-term transition pathway towards light-duty vehicle electrification. [...]
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Economic Assessment of Autonomous Electric Microtransit Vehicles
G. Sethuraman, F. Roemer, E. Loewer, F. Chang, A. Ongel, M. Lienkamp

Collection of open articles in transport research (2019). Vol. 2019, 314

Abstract
There is rapidly growing interest in autonomous electric vehicles due to their potential in improving safety, accessibility, and environmental outcomes. However, their market penetration rate is dependent on costs. Use of autonomous electric vehicles for shared-use mobility may improve their cost competitiveness. So far, most of the research has focused on the cost impact of autonomy on taxis and ridesourcing services. Singapore is planning for island-wide deployment of autonomous vehicles for both scheduled and on-demand services as part of their transit system in the year 2030. TUMCREATE developed an autonomous electric vehicle concept, a microtransit vehicle with 30-passenger capacity, which can complement the existing bus transit system. This study aims to determine the cost of autonomous electric microtransit vehicles and compare them to those of buses. A total cost of ownership (TCO) approach was used to compare the lifecycle costs. It was shown that although the acquisition costs of autonomous electric vehicles are higher than those of their conventional counterparts, they can reduce the TCO per passenger-km up to 75% and 60% compared to their conventional counterparts and buses, respectively. Document type: Article
Abstract
There is rapidly growing interest in autonomous electric vehicles due to their potential in improving safety, accessibility, and environmental outcomes. However, their market [...]
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Social-Aware Driver Assistance Systems for City Traffic in Shared Spaces
A. Fernández-Isabel, R. Fuentes-Fernández

Collection of open articles in transport research (2019). Vol. 2019, 313

Abstract
Shared spaces are gaining presence in cities, where a variety of players and mobility types (pedestrians, bicycles, motorcycles, and cars) move without specifically delimited areas. This makes the traffic they comprise challenging for automated systems. The information traditionally considered (e.g., streets, and obstacle positions and speeds) is not enough to build suitable models of the environment. The required explanatory and anticipation capabilities need additional information to improve them. Social aspects (e.g., goal of the displacement, companion, or available time) should be considered, as they have a strong influence on how people move and interact with the environment. This paper presents the Social-Aware Driver Assistance System (SADAS) approach to integrate this information into traffic systems. It relies on a domain-specific modelling language for social contexts and their changes. Specifications compliant with it describe social and system information, their links, and how to process them. Traffic social properties are the formalization within the language of relevant knowledge extracted from literature to interpret information. A multi-agent system architecture manages these specifications and additional processing resources. A SADAS can be connected to other parts of traffic systems by means of subscription-notification mechanisms. The case study to illustrate the approach applies social knowledge to predict people&rsquo s movements. It considers a distributed system for obstacle detection and tracking, and the intelligent management of traffic signals. Document type: Article
Abstract
Shared spaces are gaining presence in cities, where a variety of players and mobility types (pedestrians, bicycles, motorcycles, and cars) move without specifically delimited [...]
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“Gas pipeline wars” in the post-Soviet space: geographical aspect
T. Pototskaya

Collection of open articles in transport research (2020). Vol. 2020, 335

Abstract
The article discusses the transformation of the territorial organization of gas pipeline transport in the post-Soviet period under the influence of the system of international relations that developed between the countries of the post-Soviet space. Notably, the author establishes the following major geographical factors affecting this process: the level of provision with natural gas and the peculiarities of the transport and geographical position of the countries. The author specifically emphasizes an active, consistent and purposeful policy on this issue in Russia, Azerbaijan, Kazakhstan, and Turkmenistan, which reinforces and strengthens the geopolitical interests of these states in the examined region. Their competitive advantages are clearly indicated. Particular attention is focused on the possibility of multipurpose use of gas pipelines thanks to the connecting pipes created between them. The interest intersection of three categories of states was revealed: those of the countries in the post-Soviet space (Russia, Ukraine, Azerbaijan, Turkmenistan, Kazakhstan, Uzbekistan); those of Russia and countries located in the neighboring regions (EU, China, Turkey, Iran); those of the states actively involved in investing in geological exploration, creation of mining enterprises, gas storages, construction of compressor stations on them (USA, Great Britain, Saudi Arabia, Japan, etc.). Document type: Article
Abstract
The article discusses the transformation of the territorial organization of gas pipeline transport in the post-Soviet period under the influence of the system of international [...]
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Genetic automated machine learning assistant
J. Vanschoren, P. Gijsbers

Collection of open articles in transport research (2019). Vol. 2019, 312

Abstract
GAMA is an AutoML package for end-users and AutoML researchers. It uses genetic programming to efficiently generate optimized machine learning pipelines given specific input data and resource constraints. A machine learning pipeline contains data preprocessing as well as a machine learning algorithm, with fine-tuned hyperparameter settings. Document type: Article
Abstract
GAMA is an AutoML package for end-users and AutoML researchers. It uses genetic programming to efficiently generate optimized machine learning pipelines given specific input [...]
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A Multi-objective Optimization Model for Robust Skip-Stop Scheduling with Earliness and Tardiness Penalties
F. Rajabighamchi, E. Hajlou, E. Hassannayebi

Collection of open articles in transport research (2019). Vol. 2019, 311

Abstract
Inefficient transport systems impose extra travel time for travelers, cause dissatisfaction and reduce service levels. In this study, the demand-oriented train scheduling problem is addressed using a robust skip-stop method under uncertain arrival rates during peak hours. This paper presents alternative mathematical models, including a two-stage scenario-based stochastic programming model and two robust optimization models, to minimize the total travel time of passengers and their waiting time at stations. The modeling framework accounts for the design and implementation of robust skip-stop schedules with earliness and tardiness penalties. As a case study, each of the developed models is implemented on line No. 5 of the Tehran metro, and the results are compared. To validate the skip-stop schedules, the values of the stochastic solution and the expected value of perfect information are calculated. In addition, a sensitivity analysis is conducted to test the performance of the model under different scenarios. According to the obtained results, having perfect information can reduce up to 16% of the value of the weighted objective function. The proposed skip-stop method has been shown to save about 5% in total travel time and 49% in weighted objective function, which is a summation of travel times and waiting times as against regular all-stop service. The value of stochastic solutions is about 21% of the value of the weighted objective function, which shows that the stochastic model demonstrates better performance than the deterministic model. Document type: Article
Abstract
Inefficient transport systems impose extra travel time for travelers, cause dissatisfaction and reduce service levels. In this study, the demand-oriented train scheduling [...]
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The More Stringent, the Better? : Rationing Car Use in Bogota with Moderate and Drastic Restrictions
J. Bonilla

Collection of open articles in transport research (2019). Vol. 2019, 310

Abstract
Rationing car use based on license plate number has become a popular policy in several cities around the world to address traffic congestion and air pollution. This paper studies the effects of the moderate and drastic driving restrictions imposed as part of the Pico y Placa program on car use and air pollution in Bogota. Using data on ambient carbon monoxide, gasoline consumption, and vehicle sales and registrations, no evidence of an improvement in air quality or a reduction in car use is found in either phase of the program. On the contrary, there is some indication that, relative to the moderate phase, gasoline consumption, vehicle ownership, and carbon monoxide in the morning peak tended to increase slightly when drastic restrictions were implemented. Document type: Article
Abstract
Rationing car use based on license plate number has become a popular policy in several cities around the world to address traffic congestion and air [...]
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A Bottom-Up Approach to Lithium-Ion Battery Cost Modeling with a Focus on Cathode Active Materials
J. Leker, M. Greenwood, M. Wentker

Collection of open articles in transport research (2019). Vol. 2019, 309

Abstract
In this study, we develop a method for calculating electric vehicle lithium-ion battery pack performance and cost. To begin, we construct a model allowing for calculation of cell performance and material cost using a bottom-up approach starting with real-world material costs. It thus provides a supplement to existing models, which often begin with fixed cathode active material (CAM) prices that do not reflect raw metal price fluctuations. We collect and display data from the London Metal Exchange to show that such metal prices, in this case specifically cobalt and nickel, do indeed fluctuate and cannot be assumed to remain static or decrease consistently. We input this data into our model, which allows for a visualization of the effects of these metal price fluctuations on the prices of the CAMs. CAMs analyzed include various lithium transition metal oxide-type layered oxide (NMC and NCA) technologies, as well as cubic spinel oxide (LMO), high voltage spinel oxide (LNMO), and lithium metal phosphate (LFP). The calculated CAM costs are combined with additional cell component costs in order to calculate full cell costs, which are in turn scaled up to full battery pack costs. Economies of scale are accounted for separately for each cost fraction. Document type: Article
Abstract
In this study, we develop a method for calculating electric vehicle lithium-ion battery pack performance and cost. To begin, we construct a model allowing for calculation [...]
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Experiments and Fragility Analyses of Piping Systems Connected by Grooved Fit Joints With Large Deformability
X. Chen, Q. Shang, T. Wang, J. Li

Collection of open articles in transport research (2019). Vol. 2019, 308

Abstract
The pipes with diameter of 150mm, also called DN150, are often connected by grooved fit joints and employed as the stem pipelines, which are used to transport water vertically to different building stories and distribute it horizontally to different rooms. A large deformability is often required for the grooved fit joints to accommodate the deformation concentrated between adjacent stories during an earthquake. To this end, the grooved fit joint is often improved with a wider groove to achieve such a large deformability. However, its seismic performance has not been thoroughly studied yet. This study conducted quasi-static tests on twelve DN150 grooved fit joints, including four elbow joints and eight DN150-DN80 Tee joints. The mechanical behavior, rotational capacity and failure mode were examined and discussed. The test results indicate that the fracture of the grooved fitting and the pull-out of pipes from the grooved fitting are the major damage patterns at deformations larger than 0.1rad. At small deformations less than 0.06 rad, although slight abrasion and wear were observed on the contact surface between the galvanized steel pipe and the grooved fitting, they would not result in significant leakage. Three damage states are defined accordingly and the fragility models are developed for different grooved fit joints based on test results. Finally, seismic fragility analysis of DN150 stem pipeline system in a 10-story building was conducted. It is demonstrated that the improved joints survive under the maximum credible earthquake and the leakage is highly unlikely to occur. Document type: Article
Abstract
The pipes with diameter of 150mm, also called DN150, are often connected by grooved fit joints and employed as the stem pipelines, which are used to transport water vertically [...]
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Exploring the Influence of Truck Proportion on Freeway Traffic Safety Using Adaptive Network-Based Fuzzy Inference System
S. Zhang, H. Zhang, Y. Xing, J. Lu

Collection of open articles in transport research (2019). Vol. 2019, 306

Abstract
The truck operation of freeway has an impact on traffic safety. In particular, the gradually increasing in truck proportion will inevitably affect the freeway traffic operation of different traffic volume. In this paper, VISSIM simulation is used to supply the field data and orthogonal experimental is designed for calibrate the simulation data. Then, SSAM modeling is combined to analyze the impact of truck proportion on traffic flow parameters and traffic conflicts. The serious and general conflict prediction model based on the Adaptive Network-based Fuzzy Inference System (ANFIS) is proposed to determine the impact of the truck proportion on freeway traffic safety. The results show that when the truck proportion is around 0.4 under 3200 veh/h and 0.6 under 2600 veh/h, there are more traffic conflicts and the number of serious conflicts is more than the number of general conflicts, which also reflect the relationship between truck proportion and traffic safety. Under 3000 veh/h, travel time and average delay increasing while mean speed and mean speed of small car decreases with truck proportion increases. The mean time headway rises largely with the truck proportion increasing above 3000 veh/h. The speed standard deviation increases initially and then fall with truck proportion increasing. The lane-changing decreases while truck proportion increasing. In addition, ANFIS can accurately determine the impact of truck proportion on traffic conflicts under different traffic volume, and also validate the learning ability of ANFIS. Document type: Article
Abstract
The truck operation of freeway has an impact on traffic safety. In particular, the gradually increasing in truck proportion will inevitably affect the freeway traffic operation [...]
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Transporte aéreo estratégico militar en las operaciones militares modernas
J. Reina, R. Jiménez, J. Morán

Collection of open articles in transport research (2019). Vol. 2019, 305

Abstract
nolDebido a la urgencia de las Operaciones Militares Modernas, las fuerzas necesitan de un medio que las proyecte en tiempos relativamente cortos, donde la Capacidad de Transporte Aereo Estrategico Militar adquiere un papel preponderante. Asimismo, es importante destacar la influencia de la tecnologia en el medio aereo, que ha permitido que la capacidad de carga y pasajeros sea cada vez mayor y con menos servidumbres terrestres. Claramente la proyeccion de fuerzas puede realizarse por otros medios de locomocion, pero la velocidad y el aumento paulatino de las bodegas de carga hacen que el medio aereo pueda dotar a las fuerzas de la movilidad y flexibilidad que se requieren en los conflictos actuales. Es por esto, por lo que la presente investigacion tiene como objetivo proporcionar un analisis de la importancia e implicaciones de la Capacidad de Transporte Aereo Estrategico Militar en las Operaciones Militares Modernas. EnglishDue to the urgency of the Modern Military Operations, the forces need a means that projects them in relatively short times, where the Strategic Military Air Transport Capacity acquires a predominant role. Also, it is essential to highlight the influence of technology on the air environment, which has allowed the capacity of cargo and passengers to be increasingly greater and with fewer terrestrial easements. Noticeably, the projection of forces can be carried out by other means of locomotion, but the speed and gradual increase of cargo holdings mean that the air environment can provide the forces with the mobility and flexibility required in current conflicts. That is why the present research aims to provide an analysis of the importance and implications of the Strategic Military Air Transport Capacity in Modern Military Operations. portuguesDevido a urgencia das Operacoes Militares Modernas, as forcas precisam de um meio que as projete em tempos relativamente curtos, em que a Capacidade Estrategica de Transporte Aereo Militar adquira um papel preponderante. Alem disso, e importante destacar a influencia da tecnologia no ambito aereo, o que permitiu que a capacidade de carga e passageiros fosse cada vez maior e com menos servidoes terrestres. Claramente, a projecao de forcas pode ser realizada por outros meios de locomocao, mas a velocidade e o aumento gradual dos estoques de carga, facam com que o ambiente aereo possa fornecer as forcas da mobilidade e a flexibilidade necessarias nos conflitos atuais. E por isso que a presente investigacao visa fornecer uma analise da importância e implicacoes da capacidade do Transporte Aereo Estrategico Militar nas Operacoes Militares Modernas. Document type: Article
Abstract
nolDebido a la urgencia de las Operaciones Militares Modernas, las fuerzas necesitan de un medio que las proyecte en tiempos relativamente cortos, donde la Capacidad de Transporte [...]
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A systematic review of indicators to assess the sustainability of road infrastructure projects
M. Bakker, P. Witte, T. Spit, G. Suprayoga, G. Suprayoga

Collection of open articles in transport research (2020). Vol. 2020, 331

Abstract
Background: This study aims to examine to what extent sustainability has been incorporated into assessments of road infrastructure projects. It identifies promising approaches that include indicators reflecting core sustainability criteria, determines criteria that were insufficiently covered as indicators, and develops an integrated indicator set covering all criteria. Methods: A systematic review was performed to obtain all related papers/reports in two academic databases: Scopus and Web of Sciences. The indicators extracted from papers/reports were first coded, then evaluated by using quantitative and qualitative content analysis. Results: The project appraisal methods for decision-making is found to be a promising approach, covering more extensive criteria than others. Two criteria – namely adaptation and precaution and intergenerational equity – were hardly ever adopted as indicators. Ten main groups of indicators were extracted to construct an integrated set incorporating all core criteria. Conclusions: Some criteria appear to have become mainstream, while others deserve attention. The safest choice is to combine methods/tools or to adopt the integrated set developed for exhaustive criteria inclusion. Document type: Article
Abstract
Background: This study aims to examine to what extent sustainability has been incorporated into assessments of road infrastructure projects. It identifies promising approaches [...]
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What are the factors and needs promoting mobility-as-a-service? Findings from the Swiss Household Energy Demand Survey (SHEDS)
A. Stünzi, R. Hoerler, A. Duce, A. Patt

Collection of open articles in transport research (2020). Vol. 2020, 329

Abstract
Mobility-as-a-Service (MaaS) is a service that supports customers’ transportation needs by providing information and ticketing for a multitude of transport modes in one interface; thus, buy potentially fostering multimodality and public transport, it represents an important lever to reduce negative transportation impacts such as emissions and congestion. By means of an online survey conducted in Switzerland, we try to understand potential user needs as well as factors that would motivate the use of MaaS. Comparing the openness to use MaaS for specific trip purposes like commuting and leisure activities, we find the lowest level of openness for commuting and the highest for weekend leisure trips. Intention to reduce car usage was positively related to openness to MaaS in commuting. On the other hand, factors that positively influence openness to using MaaS for leisure activities include a higher education degree, experience with carsharing and the use of transport-related climate policy announcements directly affecting consumers. These findings suggest focusing specifically on either commuting or leisure activities when designing policy measures. ISSN:1867-0717 ISSN:1866-8887 Document type: Article
Abstract
Mobility-as-a-Service (MaaS) is a service that supports customers’ transportation needs by providing information and ticketing for a multitude of transport modes in one [...]
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Departure Time Choice (DTC) Behavior for Intercity Travel during a Long-Holiday in Bangkok, Thailand
B. Chaichannawatik, K. Kanitpong, T. Limanond

Collection of open articles in transport research (2019). Vol. 2019, 304

Abstract
Time-of-day (TOD) or departure time choice (DTC) has become an interesting issue over two decades. Many researches have intensely focused on time-of-day or departure time choice study, especially workday departures. However, the travel behavior during long-holiday/intercity travel has received relatively little attention in previous studies. This paper shows the characteristics of long-holiday intercity travel patterns based on 2012 New Year data collected in Thailand with a specific focus on departure time choice of car commuters due to traffic congestion occurring during the beginning of festivals. 590 interview data were analyzed to provide more understanding of general characteristics of DTC behavior for intercity travel at the beginning of a Bangkok long-holiday. Moreover, the Multinomial Logit Model (MNL) was used to find the car-based DTC model. The results showed that travelers tend to travel at the peak period when the parameters of personal and household are not so significant, in contrast to the trip-related characteristics and holiday variables that play important roles in traveler decision on departure time choice. Finally, some policies to distribute travel demand and reduce the repeatable traffic congestion at the beginning of festivals are recommended. Document type: Article
Abstract
Time-of-day (TOD) or departure time choice (DTC) has become an interesting issue over two decades. Many researches have intensely focused on time-of-day or departure time [...]
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Coatings & linings for oil & gas pipelines – the most effective method of corrosion protection for aged pipelines
C. Tache, I. Tache

Collection of open articles in transport research (2020). Vol. 2020, 326

Abstract
Pipelines around the world are in danger due to ageing, deposits and corrosion. Leaky fittings and cracks are an environmental hazard and cause the loss of valuable resources such as drinking water, gas, or oil. The pipelines may get corroded internally due to the nature of the fluid flowing inside and due to various other factors. The environmental and societal impact of infrastructure failure is a primary consideration for today’s pipeline operators. Without implementing safety measures and having a corrosion control program, corrosion makes transporting hazardous material unsafe. There are many methods NACE (National Association of Corrosion Engineers) recommends as part of a successful corrosion control program to protect oil and gas pipelines. Coatings and linings applied to pipelines whether above or below ground and often used in combination with cathodic protection. Different linings may be used for internal corrosion protection, provided the lining material does not degrade following long-term exposure to the transported fluid, at the pipeline pressure and temperature conditions. Document type: Article
Abstract
Pipelines around the world are in danger due to ageing, deposits and corrosion. Leaky fittings and cracks are an environmental hazard and cause the loss of valuable resources [...]
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Simulation and Experimental Study on Cuttings-Carrying for Reverse Circulation Horizontal Directional Drilling with Dual Drill Pipes
W. Zhiqiao, K. Lingrong, K. Lingrong, B. Wu, Y. Wang

Collection of open articles in transport research (2019). Vol. 2019, 301

Abstract
In the past decades, horizontal directional drilling (HDD) has been successfully used to install various pipelines in different strata. However, construction accidents such as drill-burying and drill-sticking occur occasionally when pipelines installed by HDD method in an unstable stratum such as sand cobble stratum. Recently, HDD with dual drill pipes was used to install pipelines in unstable stratum, and the effect is significant. The law of cuttings migration for HDD with dual drill pipes is still unclear. Therefore, it is necessary to study the law of cuttings migration in reverse circulation with dual drill pipes. This study performs numerical simulations and experimental research on the cuttings-carrying process in reverse circulation directional drilling with dual drill pipes. Based on the assumption of dual concentric pipes, simulations of fluid-solid two-phase flows are conducted in different flow channels between the inner and outer drill pipes. An experimental cuttings-carrying model is then established. By combining the results of the numerical simulations and experimental investigation, the hydraulic parameters of the dual drill pipe system are optimized, and the rationalities of the drill tool design and the grading selection are validated. The results of this study provide a reference cuttings-carrying model during reverse circulation HDD with dual drill pipes. Document type: Article
Abstract
In the past decades, horizontal directional drilling (HDD) has been successfully used to install various pipelines in different strata. However, construction accidents such [...]
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Route Identification Method for On-Ramp Traffic at Adjacent Intersections of Expressway Entrance
W. Wang, X. Zhu, Y. Wang, B. Wu

Collection of open articles in transport research (2019). Vol. 2019, 300

Abstract
To determine the control strategy at intersections adjacent to the expressway on-ramp, a route identification method based on empirical mode decomposition (EMD) and dynamic time warping (DTW) is established. First, the de-noise function of EMD method is applied to eliminate disturbances and extract features and trends of traffic data. Then, DTW is used to measure the similarity of traffic volume time series between intersection approaches and expressway on-ramp. Next, a three-dimensional feature vector is built for every intersection approach traffic flow, including DTW distance, space distance between on-ramp and intersection approach, and intersection traffic volume. Fuzzy C-means clustering method is employed to cluster intersection approaches into classifications and identify critical routes carrying the most traffic to the on-ramp. The traffic data are collected by inductive loops at Xujiahui on-ramp of North and South Viaduct Expressway and surrounding intersections in Shanghai, China. The result shows that the proposed method can achieve route classification among intersections for different time periods in one day, and the clustering result is significantly influenced by three dimensions of traffic flow feature vector. As an illustrative example, micro-simulation models are built with different control strategies. The simulation shows that the coordinated control of critical routes identified by the proposed method has a better performance than coordinated control of arterial roads. Conclusions demonstrated that the proposed route identification method could provide a theoretical basis for the coordinated control of traffic signals among intersections and on-ramp. Document type: Article
Abstract
To determine the control strategy at intersections adjacent to the expressway on-ramp, a route identification method based on empirical mode decomposition (EMD) and dynamic [...]
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Avoiding drunk driving with a push
L. Martinussen, M. Sømhovd

Collection of open articles in transport research (2019). Vol. 2019, 299

Abstract
The present study explores a novel approach for changing implicit attitudes toward drunk driving with behavioural training. Contrary to explicit attitudes, which people are consciously aware of and therefore can state, implicit attitudes are not necessarily consciously accessible; however, implicit attitudes also direct and affect behaviour. In order to combat problem behaviour such as drunk driving, it is, therefore, crucial to measure and target both types of attitudes. This randomised controlled study first measured implicit drunk driving attitudes. One week later, participants performed a behavioural training procedure, designed to influence implicit drunk driving attitudes, and a subsequent implicit drunk driving attitude test. We randomised young male participants into an experimental group that learned to avoid drunk driving stimuli and a control group performing a neutral version of the training setup. Results showed that behavioural training could change implicit drunk driving attitudes. However, contrary to expectations, the control group’s implicit attitudes also changed. We propose that drivers can hold both positive and negative drunk driving implicit attitudes, and a priming effect may have contributed to the results. We outline and discuss the results. Document type: Article
Abstract
The present study explores a novel approach for changing implicit attitudes toward drunk driving with behavioural training. Contrary to explicit attitudes, which people are [...]
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Can the Czech Road Tax be considered a Tax on Externalities?
P. David

Collection of open articles in transport research (2019). Vol. 2019, 298

Abstract
The transport sector is one of the important components of economic systems. Besides positive effects, it is also a source of external costs transferred to other entities. Through the evaluation of current settings of the tax base and parameters of the road tax rate progressivity it was ascertained that this tax fails to directly or indirectly reflect the external costs of transport. It is through a relatively simple adjustment of the existing road tax rates that indirect reflection of certain items of the road transport external costs may be achieved. Firstly, changes must be made in the definition of the road tax base so as to contain emissions or other parameters of externalities; subsequently, the direct reflection of the road transport external costs in the tax may be achieved. Document type: Article
Abstract
The transport sector is one of the important components of economic systems. Besides positive effects, it is also a source of external costs transferred to other entities. [...]
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Vibration Effect Produced by Raised Pavement Markers on the Exit Ramp of an Expressway
Y. Yin, R. Li, D. Zhang, Y. Wu, G. Liang, Y. Li

Collection of open articles in transport research (2019). Vol. 2019, 297

Abstract
Driving over raised pavement markers (RPMs) spaced at different spacing, the human body will experience different vibrations. To explore whether RPMs situated at the exit ramp of an expressway induce a good vibration warning effect, this paper determines the spacing of RPMs situated along a deceleration lane and curved ramp. Models of roads, vehicles, and RPMs are first established in the ADAMS software, after which an integrated human-chair model constructed in SolidWorks is imported into ADAMS, and then the complete model is formed so that vibration simulations of different types of vehicle at different spacing and speeds can be carried out. The results show that the vibration warning effects of the spacing proposed by the existing Chinese specifications and this paper are basically between level III and level IV, the driver’s subjective feeling is between less comfortable and uncomfortable, and both induce a good vibration warning effect. For a linear deceleration lane, when considering traffic safety, a spacing of 3 m is recommended; when considering the economy, a spacing of 6 m is recommended. For a curved deceleration lane and curved ramp, according to the actual curve radius, the spacing of RPMs can refer to the spacing recommended in the paper. In addition, the vibration warning effect for cars and semi-trailer trucks initially increases with an increase in the speed; then, after reaching a certain peak speed, the effect decreases with an increase in the speed, and finally, it tends to become gentle at speeds exceeding 100 km/h. The vibration warning effect for a semi-trailer truck is better than that for a car under the same spacing and speed. Document type: Article
Abstract
Driving over raised pavement markers (RPMs) spaced at different spacing, the human body will experience different vibrations. To explore whether RPMs situated at the exit [...]
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Water Supply Pipeline Risk Index Assessment Based on Cohesive Hierarchical Fuzzy Inference System
M. Fayaz, S. Ahmad, D. Kim, L. Hang

Collection of open articles in transport research (2019). Vol. 2019, 296

Abstract
As populations grow, facilities such as roads, bridges, railways lines, commercial and residential buildings, etc., must be expanded and maintained. There are extensive networks of underground facilities to fulfil the demand, such as water supply pipelines, sewage pipelines, metro structures, etc. Hence, a method to regularly assesses the risk of the underground facility failures is needed to decrease the chance of accidental loss of service or accidents that endanger people and facilities. In the proposed work, a cohesive hierarchical fuzzy inference system (CHFIS) was developed. A novel method is proposed for membership function (MF) determination called the heuristic based membership functions determination (HBMFD) method to determine an appropriate MF set for each fuzzy logic method in CHFIS. The proposed model was developed to decrease the number of rules for the full structure fuzzy inference system with all rule implementation. Four very crucial parameters were considered in the proposed work that are inputs to the proposed CHFIS model in order to calculate the risk of water supply pipelines. In order to fully implement the proposed CHFIS just 85 rules are needed while using the traditional Mamdani fuzzy inference system, 900 rules are required. The novel method greatly reduces implementation time and rule design sets that are extremely time consuming to develop and difficult to maintain. Document type: Article
Abstract
As populations grow, facilities such as roads, bridges, railways lines, commercial and residential buildings, etc., must be expanded and maintained. There are extensive networks [...]
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Evaluation of Transportation Network Reliability under Emergency Based on Reserve Capacity
X. Zhang, Q. Zhong, Q. Luo

Collection of open articles in transport research (2019). Vol. 2019, 295

Abstract
There are differences between the requirements for traffic network for traffic demand in daily and emergency situations. In order to evaluate how the network designed for daily needs can meet the surging demand for emergency evacuation, the concept of emergency reliability and corresponding evaluation method is proposed. This paper constructs a bilevel programming model to describe the proposed problem. The upper level problem takes the maximum reserve capacity multiplier as the optimization objective and considers the influence of reversible lane measures taken under emergency conditions. The lower level model adopts the combined traffic distribution/assignment model with capacity limits, to describe evacuees’ path and shelter choice behavior under emergency conditions and take into account the traits of crowded traffic. An iterative optimization method is proposed to solve the upper level model, and the lower level model is transformed into a UE assignment problem with capacity limits over a network of multiple origins and single destination, by adding a dummy node and several dummy links in the network. Then a dynamic penalty function algorithm is used to solve the problem. In the end, numerical studies and results are provided to demonstrate the rationality of the proposed model and feasibility of the proposed solution algorithms. Document type: Article
Abstract
There are differences between the requirements for traffic network for traffic demand in daily and emergency situations. In order to evaluate how the network designed for [...]
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The geoecological substantiation of pipelines to collect associated petroleum gas
D. Balashov

Collection of open articles in transport research (2019). Vol. 2019, 294

Abstract
Construction and exploitation of the gas pipeline is associated with seriously geoecological risks. The magnitude of risks depends on the kind and value of the impact of influencing factors. The factors of geoecological risk mean to the natural and technical conditions, which influences to probability of occurrence, the value of processes with adverse geoecological consequences, also the size of the expected geoecological damage during the transportation of associated petroleum gas (Gubaidullin and Korobov 2005). Territory near shore of Pechora sea between Bolvanskaya bay and Khaypudyrskaya bay is modern promising center of oil production in region. Ricing of oil production connect with ricing of associated petroleum gas (APG) production and searching of ways of effective utilization APG (instead of burning on torch) is actual challenge. The most promising way is common gathering pipeline system with one center of preparing and utilization of APG. Building and exploitation of pipelines connected with high gejecologilal risks. Evaluation and minimization of geecological risk is actual task."/jats:p" "jats:p"It is necessary to plan steps to minimizing risks (Day et al. 1998) to design stage to reduce the impact on the environment. The factor`s indicators of geoeological risk are distributed unevenly along the gas pipeline. Zoning should help to analyze the distribution of geoecological risk factors and determine territories for activities. Document type: Article
Abstract
Construction and exploitation of the gas pipeline is associated with seriously geoecological risks. The magnitude of risks depends on the kind and value of the impact of influencing [...]
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Planning urban pavement maintenance by a new interactive multiobjective optimization approach
M. Augeri, V. Nicolosi, S. Greco, S. Greco

Collection of open articles in transport research (2019). Vol. 2019, 293

Abstract
Pavement maintenance is essential to prevent the deterioration of asset value and to satisfy the expectations of all stakeholders (objectives). However, the budgets are often insufficient to keep the road pavement at optimum levels. Therefore, a decision making process ought to be used for prioritizing different maintenance activities in order to achieve pre-defined goals by optimizing the use of the available budget. One of the biggest difficulties in multiobjective optimization method is the large number of the feasible solutions (Pareto optimal set or its approximation), which makes it hard for the Decision Maker to select the best solution."br/""br/"To support interaction with the decision maker for identifying the best combination of maintenance actions, this paper proposes a new methodology named “Interactive Multiobjective Optimization-Dominance Rough Set Approach” (IMO-DRSA), using a decision-rule preference model."br/""br/"The preference information, obtained by the Decision Maker (DM) during the course of the interaction, is processed using the Dominance-based Rough Set Approach in order to achieve a decision model expressed in terms of easily understandable “if ….then …” decision rules. This approach makes possible an interaction between the analyst and the decision maker and helps the decision maker to classify maintenance options and allocate limited funds according to predefined objectives (quantitative or qualitative). An application of the proposed methodology to road pavements of an Italian urban sub-network is presented. Document type: Article
Abstract
Pavement maintenance is essential to prevent the deterioration of asset value and to satisfy the expectations of all stakeholders (objectives). However, the budgets are often [...]
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Obstacle Avoidance of Semi-Trailers Based on Nonlinear Model Predictive Control
Y. Meng, Q. Gu, L. Liu, W. Luo, G. Bai, C. Liang

Collection of open articles in transport research (2019). Vol. 2019, 292

Abstract
Obstacle avoidance is a core part of the autonomous driving of off-road vehicles, such as semi-trailers. Due to the long length of semi-trailers, the traditional obstacle avoidance controller based on the circumcircle model can ensure that there is no collision between the semi-trailer and the obstacle, but it also greatly reduces the passable area. To solve this problem, we propose a new obstacle avoidance model. In this model, the distance between the obstacle and the middle line of semi-trailers is used as the indicator of obstacle avoidance. Based on this model, we design a new obstacle avoidance controller for semi-trailers. The simulation results show that the proposed controller can ensure that no collision occurs between the semi-trailer and the obstacle. The minimum distance between the obstacle center and the semi-trailer body trajectory is greater than the sum of the obstacle radius and the safety margin. Compared with the traditional obstacle avoidance controller based on the circumcircle model, the proposed controller greatly reduces the error between the semi-trailer and the reference path during obstacle avoidance. Document type: Article
Abstract
Obstacle avoidance is a core part of the autonomous driving of off-road vehicles, such as semi-trailers. Due to the long length of semi-trailers, the traditional obstacle [...]
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Network Analysis of the Multidimensional Symptom Experience of Oncology
M. Hammer, S. Paul, N. Papachristou, E. Patiraki, S. Katsaragakis, R. Maguire, J. Armes, K. Kober, J. Levine, P. Barnaghi, F. Wright, C. Miaskowski, B. Cooper, L. McCann, Y. Conley, E. Furlong

Collection of open articles in transport research (2019). Vol. 2019, 291

Abstract
Oncology patients undergoing cancer treatment experience an average of fifteen unrelieved symptoms that are highly variable in both their severity and distress. Recent advances in Network Analysis (NA) provide a novel approach to gain insights into the complex nature of co-occurring symptoms and symptom clusters and identify core symptoms. We present findings from the first study that used NA to examine the relationships among 38 common symptoms in a large sample of oncology patients undergoing chemotherapy. Using two different models of Pairwise Markov Random Fields (PMRF), we examined the nature and structure of interactions for three different dimensions of patients’ symptom experience (i.e., occurrence, severity, distress). Findings from this study provide the first direct evidence that the connections between and among symptoms differ depending on the symptom dimension used to create the network. Based on an evaluation of the centrality indices, nausea appears to be a structurally important node in all three networks. Our findings can be used to guide the development of symptom management interventions based on the identification of core symptoms and symptom clusters within a network. Document type: Article
Abstract
Oncology patients undergoing cancer treatment experience an average of fifteen unrelieved symptoms that are highly variable in both their severity and distress. Recent advances [...]
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Distribution Organization Optimization for Inbound China Railway Express at Alataw Pass Railway Station
X. Zhu, W. Liu, L. Wang

Collection of open articles in transport research (2019). Vol. 2019, 289

Abstract
Recently, in the context of &ldquo The Belt and Road&rdquo Initiative, the China Railway Express, which has a high volume and spans a long distance has greatly facilitated the construction of international freight transport corridors between developed and developing countries. To ensure sustainable development, this paper introduces an optimization problem of a container distribution organization scheme for the China Railway Express resulting from the major existing problems arising in railway port stations, which is a special and crucial link in transportation organization of the China Railway Express. The problem of a long dwell time of inbound trains is typically concerned with the operation process in railway port stations. Taking various real-world influencing factors of efficiency into account, this paper formulates a distribution organization optimization model to minimize the total container-hours of inbound China Railway Express at Alataw Pass railway station. Subsequently, a solution method based on the main idea of a genetic algorithm is developed to solve the problem, and two examples of different modes of transportation organization are given for validating the effectiveness of the model. Finally, we compare the results between two modes under different orders of magnitude according to the characteristics of sustainability to discuss the possible change and development of the China Railway Express in the future. Document type: Article
Abstract
Recently, in the context of &ldquo The Belt and Road&rdquo Initiative, the China Railway Express, which has a high volume and spans a long distance has greatly facilitated [...]
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The Effect of Reducing Electric Car Purchase Incentives in the European Union
J. Gómez Vilchez, C. Thiel

Collection of open articles in transport research (2019). Vol. 2019, 288

Abstract
The importance of electric car purchase incentives is starting to be questioned. The objective of this paper is to explore the potential effect of reducing or removing electric car purchase public subsidies in the European Union. To this end, the system dynamics Powertrain Technology Transition Market Agent Model is used. The size and timing of purchase incentives for this technology in European countries are investigated under eight scenarios and sensitivity analysis performed. The simulations suggest that, in the short-run, the electric car market share is higher when the subsidies remain in place. In the medium-run, a purchase subsidy scheme granting &euro 3000 for plug-in hybrid electric cars and &euro 4000 for battery electric cars over the period 2020&ndash 2024 yields the fastest electric car market uptake of all the scenarios considered. We conclude that, though the current evolution of the battery price is favorable, electric car purchase subsidies remain an effective policy measure to support electro-mobility in the next years. Document type: Article
Abstract
The importance of electric car purchase incentives is starting to be questioned. The objective of this paper is to explore the potential effect of reducing or removing electric [...]
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A Bi-Objective Fuzzy Credibilistic Chance-Constrained Programming Approach for the Hazardous Materials Road-Rail Multimodal Routing Problem under Uncertainty and Sustainability
C. Zhang, Y. Sun, X. Liang, X. Li

Collection of open articles in transport research (2019). Vol. 2019, 287

Abstract
Hazardous materials transportation involves extensive risk and cannot be avoided in practice. An advanced routing, however, can help to reduce the risk by planning the best transportation routes for hazardous materials that can make effective tradeoffs between the risk objective and the economic objective. In this study, we explore the hazardous materials routing problem in the road-rail multimodal transportation network with a hub-and-spoke structure, in which the risk is measured by the multiplication of population exposure and the associated volume of hazardous materials, and minimizing the total risk of all the transportation orders of hazardous materials is set as the risk objective. It is difficult to estimate the population exposure exactly during the routing decision-making process, which results in its uncertainty. In this study, we formulate the uncertain population exposure from a fuzzy programming perspective by using triangular fuzzy numbers. Moreover, the carbon dioxide emission constraint is formulated to realize the sustainable transportation of hazardous materials. To optimize the problem under the above framework, we first establish a bi-objective fuzzy mixed integer nonlinear programming model, and then develop a three-stage exact solution strategy that the combines fuzzy credibilistic chance constraint, linearization technique, and the normalized weighting method. Finally, a computational experiment is carried out to verify the feasibility of the proposed method in dealing with the problem. The experimental results indicate that tradeoffs between the two conflicting objectives can be effectively made by using the Pareto frontier to the hazardous materials routing problem. Furthermore, the credibility level and carbon dioxide emission cap significantly influence the hazardous materials routing optimization. Their effects on the optimization result are quantified by using sensitivity analysis, which can draw some useful insights to help decision makers to better organize the hazardous materials road-rail multimodal transportation under uncertainty and sustainability. Document type: Article
Abstract
Hazardous materials transportation involves extensive risk and cannot be avoided in practice. An advanced routing, however, can help to reduce the risk by planning the best [...]
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FCG-ASpredictor: An Approach for the Prediction of Average Speed of Road Segments with Floating Car GPS Data
D. Liu, J. Chen, Z. Difeng, G. Shen, Y. Zhang

Collection of open articles in transport research (2019). Vol. 2019, 286

Abstract
The average speed (AS) of a road segment is an important factor for predicting traffic congestion, because the accuracy of AS can directly affect the implementation of traffic management. The traffic environment, spatiotemporal information, and the dynamic interaction between these two factors impact the predictive accuracy of AS in the existing literature, and floating car data comprehensively reflect the operation of urban road vehicles. In this paper, we proposed a novel road segment AS predictive model, which is based on floating car data. First, the impact of historical AS, weather, and date attributes on AS prediction has been analyzed. Then, through spatiotemporal correlations calculation based on the data from Global Positioning System (GPS), the predictive method utilizes the recursive least squares method to fuse the historical AS with other factors (such as weather, date attributes, etc.) and adopts an extended Kalman filter algorithm to accurately predict the AS of the target segment. Finally, we applied our approach on the traffic congestion prediction on four road segments in Chengdu, China. The results showed that the proposed predictive model is highly feasible and accurate. Document type: Article
Abstract
The average speed (AS) of a road segment is an important factor for predicting traffic congestion, because the accuracy of AS can directly affect the implementation of traffic [...]
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External Human–Machine Interfaces: The Effect of Display Location on Crossing Intentions and Eye Movements
W. Tempelaar, Y. Eisma, S. Brake, J. Winter, M. Hensen, S. Bergen

Collection of open articles in transport research (2019). Vol. 2019, 285

Abstract
In the future, automated cars may feature external human&ndash machine interfaces (eHMIs) to communicate relevant information to other road users. However, it is currently unknown where on the car the eHMI should be placed. In this study, 61 participants each viewed 36 animations of cars with eHMIs on either the roof, windscreen, grill, above the wheels, or a projection on the road. The eHMI showed &lsquo Waiting&rsquo combined with a walking symbol 1.2 s before the car started to slow down, or &lsquo Driving&rsquo while the car continued driving. Participants had to press and hold the spacebar when they felt it safe to cross. Results showed that, averaged over the period when the car approached and slowed down, the roof, windscreen, and grill eHMIs yielded the best performance (i.e., the highest spacebar press time). The projection and wheels eHMIs scored relatively poorly, yet still better than no eHMI. The wheels eHMI received a relatively high percentage of spacebar presses when the car appeared from a corner, a situation in which the roof, windscreen, and grill eHMIs were out of view. Eye-tracking analyses showed that the projection yielded dispersed eye movements, as participants scanned back and forth between the projection and the car. It is concluded that eHMIs should be presented on multiple sides of the car. A projection on the road is visually effortful for pedestrians, as it causes them to divide their attention between the projection and the car itself. Document type: Article
Abstract
In the future, automated cars may feature external human&ndash machine interfaces (eHMIs) to communicate relevant information to other road users. However, it is currently [...]
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Lifetime Analysis of Energy Storage Systems for Sustainable Transportation
A. Buchroithner, H. Wegleiter, P. Haidl, M. Bader, B. Schweighofer

Collection of open articles in transport research (2019). Vol. 2019, 284

Abstract
On the path to a low-carbon future, advancements in energy storage seem to be achieved on a nearly daily basis. However, for the use-case of sustainable transportation, only a handful of technologies can be considered, as these technologies must be reliable, economical, and suitable for transportation applications. This paper describes the characteristics and aging process of two well-established and commercially available technologies, namely Lithium-Ion batteries and supercaps, and one less known system, flywheel energy storage, in the context of public transit buses. Beyond the obvious use-case of onboard energy storage, stationary buffer storage inside the required fast-charging stations for the electric vehicles is also discussed. Calculations and considerations are based on actual zero-emission buses operating in Graz, Austria. The main influencing parameters and effects related to energy storage aging are analyzed in detail.Based on the discussed aging behavior, advantages, disadvantages, and a techno-economic analysis for both use-cases is presented. A final suitability assessment of each energy storage technology concludes the use-case analysis. Document type: Article
Abstract
On the path to a low-carbon future, advancements in energy storage seem to be achieved on a nearly daily basis. However, for the use-case of sustainable transportation, only [...]
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Influence Mechanism of Geometric Characteristics of Water Conveyance System on Extreme Water Hammer during Load Rejection in Pumped Storage Plants
J. Zhang, C. Sheng, X. Yu, G. Li

Collection of open articles in transport research (2019). Vol. 2019, 283

Abstract
Pumped storage plants (PSPs) have achieved rapid development and deployment worldwide since the penetration of intermittent renewable energy sources (RES). Hydraulic transient analysis in the PSP, to obtain the control parameters such as extreme water hammer pressure, is vital to the safe design of water conveyance system. Empirically, simultaneous load rejection (SLR) is commonly accepted as the control condition for extreme water hammer, while it is not completely true for the PSP. Employing theoretical analysis and numerical simulation, this study systematically investigates the effects of geometric characteristics on the extreme water hammer, and reveals the mechanism leading to the maximum spiral case pressure (SCP) during a two-stage load rejection (TLR) process. The results indicate that the extreme water hammer pressure is closely related to geometric characteristics of the water conveyance system, performing the allocation of the water inertia time constant of the main and branch pipelines. When the water inertia time constant in the branch pipe is dominant (&eta 1 > 0.24 for example), the maximum SCP will occur in TLR conditions rather than SLR. Moreover, the maximum SCP is almost the same, providing the water inertia time constants of both the main and branch pipelines are kept constant. Document type: Article
Abstract
Pumped storage plants (PSPs) have achieved rapid development and deployment worldwide since the penetration of intermittent renewable energy sources (RES). Hydraulic transient [...]
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The open diffusion data derivatives, brain data upcycling via integrated publishing of derivatives and reproducible open cloud services
I. Dinov, F. Pestilli, D. Bullock, P. Avesani, P. Avesani, A. Patterson, O. Sporns, E. Garyfallidis, L. Wang, R. Henschel, S. Hayashi, D. Hancock, Y. Qian, B. Caron, B. McPherson, C. Caiafa, C. Caiafa, L. Kitchell, A. Saykin, E. Olivetti, E. Olivetti

Collection of open articles in transport research (2019). Vol. 2019, 282

Abstract
We describe the Open Diffusion Data Derivatives (O3D) repository: an integrated collection of preserved brain data derivatives and processing pipelines, published together using a single digital-object-identifier. The data derivatives were generated using modern diffusion-weighted magnetic resonance imaging data (dMRI) with diverse properties of resolution and signal-to-noise ratio. In addition to the data, we publish all processing pipelines (also referred to as open cloud services). The pipelines utilize modern methods for neuroimaging data processing (diffusion-signal modelling, fiber tracking, tractography evaluation, white matter segmentation, and structural connectome construction). The O3D open services can allow cognitive and clinical neuroscientists to run the connectome mapping algorithms on new, user-uploaded, data. Open source code implementing all O3D services is also provided to allow computational and computer scientists to reuse and extend the processing methods. Publishing both data-derivatives and integrated processing pipeline promotes practices for scientific reproducibility and data upcycling by providing open access to the research assets for utilization by multiple scientific communities. Design Type(s)data integration objective • database creation objectiveMeasurement Type(s)brainTechnology Type(s)magnetic resonance imagingFactor Type(s)Voxel SizeSample Characteristic(s)Homo sapiens • brain Machine-accessible metadata file describing the reported data (ISA-Tab format) Document type: Preprint
Abstract
We describe the Open Diffusion Data Derivatives (O3D) repository: an integrated collection of preserved brain data derivatives and processing pipelines, published together [...]
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The Parker Project: Cross-Brand Service Testing Using V2G
L. Noel, S. Hashemi, B. Christensen, T. Soerensen, T. Sousa, P. Andersen

Collection of open articles in transport research (2019). Vol. 2019, 280

Abstract
The Parker project sought to experimentally validate that contemporary series-produced electric vehicles (EVs), capable of V2G, are ready to participate in a number of advanced grid services. In such services, the timing, size and direction of power and energy exchanged between the EV battery and grid is controlled as to support either a single building, the local neighborhood or the regional power system. Vehicles purposely designed for such services are referred to as grid integrated electric vehicles (GIVs). The field of research, describing how GIVs may be used to actively support the power system, is called Vehicle&ndash Grid Integration (VGI).The purpose of this paper is to present how the Danish Parker project has systematically categorized a range of grid services, collected in a service catalog, and then illustrate state-of-the-art EVs ability to support such services through experimental validation. Results are presented for three different tests performed in Parker marginal emission factor charging, frequency containment reserves and a performance test for controlling power setpoints. The ultimate aim of this paper, and the Parker project, is to promote the GIV concept so that it may inform the design and capabilities of present and future EVs, EV supply equipment (EVSE) and communication standards. Document type: Article
Abstract
The Parker project sought to experimentally validate that contemporary series-produced electric vehicles (EVs), capable of V2G, are ready to participate in a number of advanced [...]
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Cost-Effective, Time-Efficient Passenger Rail System for the Eastern United States
D. Kim, J. Mathias

Collection of open articles in transport research (2019). Vol. 2019, 279

Abstract
A program was developed using a genetic algorithm and automated lookup features to design an efficient passenger rail system for the eastern-half of the United States connecting large cities, metropolitan populations greater than two million, with overnight rail service. The results of the program predicted a passenger starting at the farthest point of the system boards the train at 16:02 on average and arrives at a different point of the system at 07:57 on average the following day, assuming the train travels an average speed of 70 mph. The design used actual distances by train track where possible. The system was modeled with six trains that meet at a hub and exchange passengers and continue on to their destination. The optimal solution had a total one-way minimum distance of 4334 km (2693 miles). Assuming the same ridership that currently exists on a popular train route, ticket prices would average $62 (USD) for a one-way ticket. For this system to be feasible, the government would need to own or lease one set of tracks for all the routes determined, build a hub for passengers to transfer trains near Charleston, WV, and ensure the trains are unimpeded by other trains. Installing tracks that go around cities that the trains do not stop at would be a great benefit also. With advances in communication, GPS, and train control technology, this article points out the benefits of publically available tracks to form a transportation network similar to that found in road, air, and water traffic. Document type: Article
Abstract
A program was developed using a genetic algorithm and automated lookup features to design an efficient passenger rail system for the eastern-half of the United States connecting [...]
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Framework for Assessing Public Transportation Sustainability in Planning and Policy-Making
L. Karjalainen, S. Juhola

Collection of open articles in transport research (2019). Vol. 2019, 278

Abstract
Transportation plays a key role in urban sustainability planning and urban greenhouse gas emission reductions. Globally, cities have established sustainability agendas and policies to guide the shift from traditional private automobile dependent transportation systems towards an increased use of public transportation, cycling, and walking. While the surrounding physical urban form and governance structures condition public transportation services, there are also many other factors to consider when discussing sustainability. As such, comprehensive planning and policy-oriented assessment frameworks that are independent of local conditions are still largely missing in literature. This paper presents a Public Transportation Sustainability Indicator List (PTSIL) that provides a platform for an integrated assessment of environmental, economic, and social dimensions of sustainability through an indicator-based approach. To demonstrate its use, the PTSIL is applied to analyze the policy documents of public transportation agencies in Helsinki, Finland, and Toronto, Canada. The results show that while both cities achieve relatively high scores in all dimensions, there is still high variability among individual indicators. The PTSIL presents a missed stepping stone between descriptive definitions of transportation sustainability and case specific sustainability performance assessments, offering an opportunity within the planning and policy-making sectors to review, assess, and develop public transportation services comprehensively. Document type: Article
Abstract
Transportation plays a key role in urban sustainability planning and urban greenhouse gas emission reductions. Globally, cities have established sustainability agendas and [...]
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Queue-Based Modeling of the Aircraft Arrival Process at a Single Airport
M. Mitici, E. Itoh

Collection of open articles in transport research (2019). Vol. 2019, 277

Abstract
This paper proposes data-driven queuing models and solutions to reduce arrival time delays originating from aircraft arrival processing bottlenecks at Tokyo International Airport. A data-driven analysis was conducted using two years of radar tracks and flight plans from 2016 and 2017. This analysis helps not only to understand the bottlenecks and operational strategies of air traffic controllers, but also to develop mathematical models to predict arrival delays resulting from increased, future aircraft traffic. The queue-based modeling approach suggests that one potential solution is to expand the realization of time-based operations, efficiently shifting from traffic flow control to time-based arrival management. Furthermore, the proposed approach estimates the most effective range of transition points, which is a key requirement for designing extended arrival management systems while offering automation support to air traffic controllers. Document type: Article
Abstract
This paper proposes data-driven queuing models and solutions to reduce arrival time delays originating from aircraft arrival processing bottlenecks at Tokyo International [...]
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Effects of Smart City Policies on Green Total Factor Productivity: Evidence from a Quasi-Natural Experiment in China
Y. Qu, B. Xin

Collection of open articles in transport research (2019). Vol. 2019, 276

Abstract
When cities develop rapidly, there are negative effects such as population expansion, traffic congestion, resource shortages, and pollution. It has become essential to explore new types of urban development patterns, and thus, the concept of the &ldquo smart city&rdquo has emerged. The purpose of this paper is to investigate the links between smart city policies and urban green total factor productivity (GTFP) in the context of China. Based on panel data of 200 cities in China from 2007&ndash 2016 and treating smart city policy as a quasi-natural experiment, the paper uses a difference-in-differences propensity score matching (PSM-DID) approach to prevent selection bias. The results show: (a) Smart city policies can significantly increase urban GTFP by 16% to 18% (b) the larger the city, the stronger and more significant this promotion. Document type: Article
Abstract
When cities develop rapidly, there are negative effects such as population expansion, traffic congestion, resource shortages, and pollution. It has become essential to explore [...]
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The Relationship Between People’s Environmental Considerations and Pro-environmental Behavior in Lithuania
A. Balundė, A. Balundė, G. Perlaviciute, L. Steg

Collection of open articles in transport research (2019). Vol. 2019, 275

Abstract
Given the need for global action on climate change, it is crucial to comprehend which factors motivate people in different countries to act more pro-environmentally. Lithuania is a post-socialist country that has recently increased commitment to foster pro-environmental behavior of individuals, by implementing interventions that target mainly the personal costs and benefits of relevant behaviors. Yet, research suggests that people’s general environmental considerations, namely biospheric values and environmental self-identity, can drive people’ pro-environmental behavior and may be important targets for interventions. These studies, however, have been mostly conducted in Western Europe and the United States, with limited evidence of relationship between people’s biospheric values, environmental self-identity and pro-environmental behaviors across different countries and cultures. We performed a correlational study with a convenience sample in Lithuania (n = 334). Consistent with previous studies and the theory, our study revealed that people’s general environmental considerations were positively related with recycling and environmental activism, but not with fuel-efficient driving and the use of sustainable transportation in Lithuania. We conclude that general environmental considerations are related to pro-environmental behaviors beyond Western Europe and the United States. Yet, future studies need to examine the boundary conditions of this relationship and test whether interventions targeting environmental consideration can be effective to promote pro-environmental behavior. Document type: Article
Abstract
Given the need for global action on climate change, it is crucial to comprehend which factors motivate people in different countries to act more pro-environmentally. Lithuania [...]
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Case Study of Holistic Energy Management Using Genetic Algorithms in a Sliding Window Approach
M. Steinstraeter, K. Minnerup, T. Herrmann, M. Lienkamp

Collection of open articles in transport research (2019). Vol. 2019, 273

Abstract
Energy management systems are used to find a compromise between conflicting goals that can be identified for battery electric vehicles. Typically, these are the powertrain efficiency, the comfort of the driver, the driving dynamics, and the component aging. This paper introduces an optimization-based holistic energy management system for a battery electric vehicle. The energy management system can adapt the vehicle velocity and the power used for cabin heating, in order to minimize the overall energy consumption, while keeping the total driving time and the cabin temperature within predefined limits. A genetic algorithm is implemented in this paper. The approach is applied to different driving cycles, which are optimized by dividing them into distinctive time frames. This approach is referred to as the sliding window approach. The optimization is conducted with two separate driving cycles, the New European Driving Cycle (NEDC) and a recorded real-world drive. These are analyzed with regard to the aspects relevant to the energy management system, and the optimization results for the two cycles are compared. The results presented in this paper demonstrate the feasibility of the sliding window approach. Moreover, they reveal the differences in fundamental parameters between the NEDC and the recorded drive and how they affect the optimization results. The optimization leads to an overall reduction in energy consumption of "inline-formula" "math display="inline"" "semantics" "mrow" "mn"3.37"/mn" "mo"%"/mo" "/mrow" "/semantics" "/math" "/inline-formula" for the NEDC and "inline-formula" "math display="inline"" "semantics" "mrow" "mn"3.27"/mn" "mo"%"/mo" "/mrow" "/semantics" "/math" "/inline-formula" for the recorded drive, without extending the travel time. Document type: Article
Abstract
Energy management systems are used to find a compromise between conflicting goals that can be identified for battery electric vehicles. Typically, these are the powertrain [...]
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Research into a Multi-Variate Surveillance Data Fusion Processing Algorithm
Y. Mao, Y. Hu, Y. Yang

Collection of open articles in transport research (2019). Vol. 2019, 272

Abstract
Targeted information sources include radar and ADS (Automatic Dependent Surveillance) for civil ATM (Air Traffic Management) systems, and the new navigation system based on satellites has the capability of global coverage. In order to solve the surveillance problem in mid-and-high altitude airspace and approaching airspace, this paper proposes a filter-based covariance matrix weighting method, measurement variance weighting method, and measurement-first weighted fusion method weighting integration algorithm to improve the efficiency of data integration calculation under fixed accuracy. Besides this, this paper focuses on the technology of the integration of a multi-radar surveillance system and automated related surveillance system in the ATM system and analyzes the constructional method of a multigeneration surveillance data integration system, as well as establishing the targeted model of sensors and the target track and designing the logical structure of multi-radar and ADS data integration. Document type: Article
Abstract
Targeted information sources include radar and ADS (Automatic Dependent Surveillance) for civil ATM (Air Traffic Management) systems, and the new navigation system based on [...]
- 0
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Study of Pipeline Penetration Based on CEL in Clay
H. Hong, Z. Zhigang, L. Tao, L. Jia, N. Jian

Collection of open articles in transport research (2020). Vol. 2020, 293

Abstract
In deep water, pipelines are usually laid directly on the seabed. During the laying process, the pipe typically penetrates into the seabed by a fraction of a diameter. The vertical embedment of pipeline and formation of berm during penetration have a significant effect on the pipeline stability. This study aims to investigate the vertical pipeline penetration at uniform and normal consolidated clay, by carrying out a series of numerical analyses, in which the coupled Eulerian-Lagrangian method (CEL) is incorporated to enable large deformation simulation. These analyses have been compared with collapse loads calculated using the theory solution. The results show that the CEL method is very suitable for simulating large-deformation pipesoil interaction. Document type: Article
Abstract
In deep water, pipelines are usually laid directly on the seabed. During the laying process, the pipe typically penetrates into the seabed by a fraction of a diameter. The [...]
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Unpacking the Smart Mobility Concept in the Dutch Context Based on a Text Mining Approach
E. Klaassen, T. Manders

Collection of open articles in transport research (2019). Vol. 2019, 271

Abstract
Existing mobility solutions are criticized for falling short of effectively addressing transport issues and sustainability challenges. In this light, smart mobility has received increasing attention. In the Netherlands, the smart mobility concept triggered various developments, leading to the uptake of initiatives for real-life experimentation, accompanied by an increase in media attention. While the concept is making its way through Dutch society, its meaning for practice remains unspecified. Therefore, this paper aims to unpack the meaning of the smart mobility concept, by analyzing Dutch news articles and initiatives&rsquo websites using text mining and qualitative content analysis. The analyses reveal some ambiguous meanings for the smart mobility concept, demonstrating on the one hand a focus on incremental technological innovations that bring forward car-based solutions for short-term fixes, while on the other hand promising to address car-related issues and fundamentally change the mobility system by taking long-term challenges into account. In general, smart mobility seems to be about optimizations and maintaining the status quo rather than challenging it, although there are a few deviating and more critical voices. The smart mobility concept mobilizes actors and resources, but considering the ambiguities, these developments should be critically evaluated when proposed as solutions to transport issues and sustainability challenges. Document type: Article
Abstract
Existing mobility solutions are criticized for falling short of effectively addressing transport issues and sustainability challenges. In this light, smart mobility has received [...]
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Battery Models for Battery Powered Applications: A Comparative Study
C. Spataro, V. Castiglia, M. Trapanese, R. Miceli, N. Campagna, F. Viola, R. Mastromauro

Collection of open articles in transport research (2020). Vol. 2020, 289

Abstract
Battery models have gained great importance in recent years, thanks to the increasingly massive penetration of electric vehicles in the transport market. Accurate battery models are needed to evaluate battery performances and design an efficient battery management system. Different modeling approaches are available in literature, each one with its own advantages and disadvantages. In general, more complex models give accurate results, at the cost of higher computational efforts and time-consuming and costly laboratory testing for parametrization. For these reasons, for early stage evaluation and design of battery management systems, models with simple parameter identification procedures are the most appropriate and feasible solutions. In this article, three different battery modeling approaches are considered, and their parameters’ identification are described. Two of the chosen models require no laboratory tests for parametrization, and most of the information are derived from the manufacturer’s datasheet, while the last battery model requires some laboratory assessments. The models are then validated at steady state, comparing the simulation results with the datasheet discharge curves, and in transient operation, comparing the simulation results with experimental results. The three modeling and parametrization approaches are systematically applied to the LG 18650HG2 lithium-ion cell, and results are presented, compared and discussed. Document type: Article
Abstract
Battery models have gained great importance in recent years, thanks to the increasingly massive penetration of electric vehicles in the transport market. Accurate battery [...]
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An Overview of, and a Definition, Ecosystem and System Architecture for Electric Mobility as a Service (eMaaS)
J. Garcia, G. Lenz, G. Bonnema, S. Haveman

Collection of open articles in transport research (2019). Vol. 2019, 270

Abstract
Mobility as a Service (MaaS) is a concept that aligns with both current and future mobility demands of users, namely intermodal, personalized, on-demand and seamless. Although the number of shared mobility, electric mobility and multimodal passenger transport users is rapidly growing, until now, the list of MaaS and electric Mobility as Service (eMaaS) providers is quite short. This could partly be explained by the lack of a common architecture that facilitates the complex integration of all actors involved in the (e)MaaS ecosystem. The goal of this publication is to give an overview of the state of the art regarding (e)MaaS&rsquo ecosystems and architectures. Moreover, it aims to support the further development of eMaaS by proposing a definition and a novel system architecture for eMaaS. Firstly, the state of the art of the MaaS ecosystem is reviewed. Secondly, the eMaaS ecosystem that builds upon our definition of eMaaS is described and the MaaS system- and technical- architectures found in literature are reviewed. Finally, an eMaaS architecture that focuses on the integration of MaaS and electric mobility systems is presented. With the definition, ecosystem and system architecture presented in this work, the aim is to support the further development of the eMaaS concept. Document type: Article
Abstract
Mobility as a Service (MaaS) is a concept that aligns with both current and future mobility demands of users, namely intermodal, personalized, on-demand and seamless. Although [...]
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Key factors for the implementation and integration of innovative ICT solutions in SMEs and large companies involved in the multimodal transport of dangerous goods
M. Mayrhofer, F. Santarremigia, G. Molero, S. Awad-Núñez, A. Kassabji, S. Poveda-Reyes

Collection of open articles in transport research (2019). Vol. 2019, 269

Abstract
The increased number of transports with dangerous goods (TDG) increases the risk of both accidents and terrorist attacks. Digitalisation is crucial in order to avoid human errors and to increase safety, security and efficiency, however there are few research studies that analyse digitalisation for the TDG, this being the first time, to the author’s knowledge, that barriers to the implementation of information and communication technology (ICT) solutions for the transport of dangerous goods has been analysed. A new elicitation methodology called the ‘implementation acceleration methodology for ICT (IAM-ICT)’ has been created, with the aim of identifying and hierarchizing potential barriers to the implementation and integration of ICT solutions involved in the multimodal TDG, and with a view to overcoming the most relevant problems at an early stage. This methodology combines user-driven innovation (UDI), the analytic hierarchy process (AHP) and Bayesian networks. The application of this methodology, which is easily replicable in other fields, will enable a better design of ICT solutions so that they can be implemented and integrated in SMEs and large companies. The results show a hierarchy of potential barriers for a multi-modular ICT solution used as use case study, in two different co-designed schemes for a small and medium enterprise (SME) and for a large company. Document type: Article
Abstract
The increased number of transports with dangerous goods (TDG) increases the risk of both accidents and terrorist attacks. Digitalisation is crucial in order to avoid human [...]
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Speed profile optimization of catenary-free electric trains with lithium-ion batteries
N. Ghaviha, M. Bohlin, C. Holmberg, E. Dahlquist

Collection of open articles in transport research (2019). Vol. 2019, 268

Abstract
Catenary-free operated electric trains, as one of the recent technologies in railway transportation, has opened a new field of research: speed profile optimization and energy optimal operation of catenary-free operated electric trains. A well-formulated solution for this problem should consider the characteristics of the energy storage device using validated models and methods. This paper discusses the consideration of the lithium-ion battery behavior in the problem of speed profile optimization of catenary-free operated electric trains. We combine the single mass point train model with an electrical battery model and apply a dynamic programming approach to minimize the charge taken from the battery during the catenary-free operation. The models and the method are validated and evaluated against experimental data gathered from the test runs of an actual battery-driven train tested in Essex, UK. The results show a significant potential in energy saving. Moreover, we show that the optimum speed profiles generated using our approach consume less charge from the battery compared to the previous approaches. Document type: Article
Abstract
Catenary-free operated electric trains, as one of the recent technologies in railway transportation, has opened a new field of research: speed profile optimization and energy [...]
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Principal Component Analysis of the Potential for Increased Rail Competitiveness in East-Central Europe
S. Duleba, B. Farkas

Collection of open articles in transport research (2019). Vol. 2019, 267

Abstract
Increased rail competitiveness has been the objective of many countries around the world, including member states of the EU. Although railway market liberalization has always been accompanied by high expectations of increased efficiency and competitiveness, the overall impact of such decisions can be considered controversial. This paper aims to contribute to the scientific debate by conducting a factor analysis of some East-Central European countries from the aspect of rail freight competitiveness. Since many highly correlated factors influence competitiveness, its mathematical&ndash statistical representation and analysis is difficult due to the high number of dimensions of the factor space. Moreover, competitiveness cannot be measured directly only as a latent variable which is a feature of Principal Component Analysis (PCA). The introduced PCA, model by way of reducing the number of dimensions, can highlight the relations among the attributes and determine the most crucial issues capable of increasing rail competitiveness in the given countries and also of clustering those national railway markets. Recommendations for structural changes in national rail freight markets of the region are also supplied. Our results show that international rail competitiveness depends rather on market efficiency than on market liberalization due to the fact that the Global Competitiveness Index and Export/Import attributes did not significantly correlate with market concentration. As for the larger domestic rail freight sectors, small freight forwarders&mdash spawned by liberalization&mdash are shown to play a significant role in increasing competitiveness. Document type: Article
Abstract
Increased rail competitiveness has been the objective of many countries around the world, including member states of the EU. Although railway market liberalization has always [...]
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Slow Steaming as Part of SECA Compliance Strategies among RoRo and RoPax Shipping Companies
J. Woxenius, Z. Raza, C. Finnsgård

Collection of open articles in transport research (2019). Vol. 2019, 266

Abstract
Many geographically peripheral member states of the EU are critically dependent on short sea Roll-on/Roll-off (RoRo) and mixed freight&ndash passenger (RoPax) shipping services for intra-European trade. The implementation of the Sulfur Emission Control Area (SECA) regulation was expected to raise the operating cost for RoRo and RoPax shipping, and slow steaming was proposed as an immediate solution to save the increased cost. Previous research has investigated the issue of slow steaming and SECA using a quantitative approach. However, the reaction of the RoRo and RoPax shipping firms toward slow steaming as a mitigating factor in the face of expected additional SECA compliance costs using qualitative methodology has not been explored yet. In addition, the knowledge regarding the impact of slow steaming on the competitiveness of short sea RoRo and RoPax with respect to service quality is limited. This article has addressed these issues through the analysis of multiple cases focusing on RoRo and RoPax firms operating in the North and Baltic Seas. Overall, our findings suggest that the 0.1% SECA regulation of 2015 requiring the use of higher-priced MGO has not caused slow steaming in the RoRo and RoPax segments to a large extent. The increased bunker prices are partially transferred to the customers via increased Bunker Adjustment Factor and partly borne by the shipowners. We have found that out of 11 case firms in our study only one RoRo and one RoPax firm have reduced vessel speeds to compensate for the additional SECA compliance costs. We conclude that for RoPax and RoRo segment bunker prices, rigorous competition and, most important, different service quality requirements have significantly restricted the potential implementation of slow steaming. Document type: Article
Abstract
Many geographically peripheral member states of the EU are critically dependent on short sea Roll-on/Roll-off (RoRo) and mixed freight&ndash passenger (RoPax) shipping services [...]
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A fully coupled fluid-structure interaction simulation of three-dimensional dynamic ductile fracture in a steel pipeline
R. Talemi, S. Brown, H. Mahgerefteh, S. Martynov, S. Cooreman

Collection of open articles in transport research (2019). Vol. 2019, 265

Abstract
Long running fractures in high-pressure pipelines transporting hazardous fluid are catastrophic events resulting in pipeline damage and posing safety and environmental risks. Therefore, the ductile fracture propagation control is an essential element of the pipeline design. In this study, a coupled fluid-structure interaction modelling is used to simulate the dynamic ductile fractures in steel pipelines. The proposed model couples a fluid dynamics model describing the pipeline decompression and the fracture mechanics of the deforming pipeline exposed to internal and back-fill pressures. To simulate the state of the flow in a rupturing pipeline, a compressible one-dimensional computational fluid dynamics model is applied, where the fluid properties are evaluated using a rigorous thermodynamic model. The ductile failure of the steel pipeline is described as an extension of the modified Bai-Wierzbicki model implemented in a finite element code. The proposed methodology has successfully been applied to simulate a full-scale pipeline burst test performed by British Gas Company, which involved rupture of a buried X70 steel pipeline, initially filled with rich natural gas at 11.6 MPa and −5 °C. Document type: Article
Abstract
Long running fractures in high-pressure pipelines transporting hazardous fluid are catastrophic events resulting in pipeline damage and posing safety and environmental risks. [...]
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The Color of Health: Residential Segregation, Light Rail Transit Developments, and Gentrification in the United States
J. Roberts, S. Wu, S. Tehrani

Collection of open articles in transport research (2019). Vol. 2019, 264

Abstract
the modern urban−suburban context becomes increasingly problematic with traffic congestion, air pollution, and increased cost of living, city planners are turning their attention to transit-oriented development as a strategy to promote healthy communities. Transit-oriented developments bring valuable resources and improvements in infrastructure, but they also may be reinforcing decades-old processes of residential segregation, gentrification, and displacement of low-income residents and communities of color. Careful consideration of zoning, neighborhood design, and affordability is vital to mitigating the impacts of transit-induced gentrification, a socioeconomic by-product of transit-oriented development whereby the provision of transit service “upscales” nearby neighborhood(s) and displaces existing community members with more affluent and often White residents. To date, the available research and, thus, overall understanding of transit-induced gentrification and the related social determinants of health are limited and mixed. In this review, an overview of racial residential segregation, light rail transit developments, and gentrification in the United States has been provided. Implications for future transit-oriented developments are also presented along with a discussion of possible solutions. Document type: Article
Abstract
the modern urban−suburban context becomes increasingly problematic with traffic congestion, air pollution, and increased cost of living, city planners are turning their [...]
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Control of a Multiphase Buck Converter, Based on Sliding Mode and Disturbance Estimation, Capable of Linear Large Signal Operation
R. Pajer, A. Chowdhury, M. Rodič

Collection of open articles in transport research (2019). Vol. 2019, 263

Abstract
Power-hardware-in-the-loop systems enable testing of power converters for electric vehicles (EV) without the use of real physical components. Battery emulation is one example of such a system, demanding the use of bidirectional power flow, a wide output voltage range and high current swings. A multiphase synchronous DC-DC converter is appropriate to handle all of these requirements. The control of the multiphase converter needs to make sure that the current is shared equally between phases. It is preferred that the closed-loop dynamic model is linear in a wide range of output currents and voltages, where parameter variations, control signal limits, dead time effects, and so on, are compensated for. In the case presented in this paper, a cascade control structure was used with inner sliding mode control for phase currents. For the outer voltage loop, a proportional controller with output current feedforward compensation was used. Disturbance observers were used in current loops and in the voltage loop to compensate mismatches between the model and the real circuit. The tuning rules are proposed for all loops and observers, to simplify the design and assure operation without saturation of control signals, that is, duty cycle and inductor current reference. By using the proposed control algorithms and tuning rules, a linear reduced order system model was devised, which is valid for the entire operational range of the converter. The operation was verified on a prototype 4-phase synchronous DC-DC converter. Document type: Article
Abstract
Power-hardware-in-the-loop systems enable testing of power converters for electric vehicles (EV) without the use of real physical components. Battery emulation is one example [...]
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The Impact of Different Incentive Policies on Hybrid Electric Vehicle Demand and Price: An International Comparison
J. Whitehead, S. Washington, J. Franklin

Collection of open articles in transport research (2019). Vol. 2019, 262

Abstract
Significant efforts to incentivize the uptake of energy efficient vehicles (EEVs) are evident across the globe. Given EEV markets are dynamic, and consumer demand may fluctuate in response to incentives, this may also lead to other market forces influencing prices. An analysis of EEV incentives, therefore, must account for the possible endogeneity between demand and pricing. Here we estimate the effects of different types of incentives on the demand and price premiums of a specific group of EEVs: plug-in and conventional hybrid electric vehicles (HEVs). For the first time we dis-entangle the endogeneity between HEV demand and price, using error components three-stage least squares (EC3SLS) regression, and establish that increased HEV price premiums lead to reduced demand. In turn, we also establish that increased HEV demand leads to lower price premiums. Additionally, we find that one-off subsidies are associated with higher consumer demand, however, unlike other types of incentives, are also associated with higher HEV price premiums. This finding suggests that HEV manufacturers and/or dealers are absorbing a significant monetary benefit from one-off subsidies, raising a question regarding the appropriateness of HEV subsidies, particularly in non-HEV manufacturing nations. We also find that higher fuel prices are associated with higher HEV demand and price premiums. Document type: Article
Abstract
Significant efforts to incentivize the uptake of energy efficient vehicles (EEVs) are evident across the globe. Given EEV markets are dynamic, and consumer demand may fluctuate [...]
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A Brief Analysis of the Current Situation and Development Trend on Green Transportation Standard System
W. Wang, J. Han, Y. Shi

Collection of open articles in transport research (2020). Vol. 2020, 277

Abstract
It is great significance to improve green transportation standards system for promoting the construction of ecological civilization and the sustainable development of recycling and low carbon of transportation. This paper summarizes the status of green transportation standards system and the progress of standard publication and revision. According to the key areas and links of green transportation development, the development trends of green transportation and the requirement of green transportation standards were analysed, and policy recommendations for improving the construction of green transportation standards system was proposed. The paper is trying to provide decisive support for the industry to promote the development of green transportation standardization. Document type: Article
Abstract
It is great significance to improve green transportation standards system for promoting the construction of ecological civilization and the sustainable development of recycling [...]
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Road transport infrastructure: a longitudinal case study (2009-2017)
R. Freitas, R. Schirrmeister, F. Zatta, R. Oliveira, W. Gonçalves

Collection of open articles in transport research (2019). Vol. 2019, 261

Abstract
This article investigates the economic gains with the reduction of logistic costs after the asphalt pavement of the highway MT 235 for a Brazilian crystal sugar and alcohol industry. Investment in infrastructure is an attribute that increases economic growth and increases the competitiveness of companies. As far as road transport infrastructure is concerned, the problems are not limited to a specific area, but stretches of highways, which link urban transportation and ports to the generation and transmission of electricity, among others. Only 12.2% of Brazilian highways are paved. This work is the result of a longitudinal case study with participant observation, in a time line from 2009 to 2017. It was possible to identify that, after improvements in road transport infrastructure, the asphalt pavement of the highway MT 235 made possible a gain in travel time and a decrease in logistics costs, which led to the closure of the activities of one of the subsidiaries of the company studied, located in Manaus (Amazonas), in 2009. With the benefits of the asphalt pavement of the MT 235, in 2017 we found that sales volume increased 650% in relation to 2011, logistics costs have been significantly reduced in relation to gross revenues, maintaining an average of 11.58%. In 2017, the logistic costs of the company studied were 12.61% versus 20.7% from the group of Brazilian agribusiness companies. The findings show that investments in road transport infrastructure are crucial when it comes to fostering trade and competitiveness of domestic products in international markets, by reducing logistics costs. Document type: Article
Abstract
This article investigates the economic gains with the reduction of logistic costs after the asphalt pavement of the highway MT 235 for a Brazilian crystal sugar and alcohol [...]
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Effects of Highway Landscapes on Drivers’ Eye Movement Behavior and Emergency Reaction Time: A Driving Simulator Study
F. Guo, J. Lee, J. Lee, Y. Chen, M. Li, J. Xiong

Collection of open articles in transport research (2019). Vol. 2019, 260

Abstract
This study aims at investigating the effects of highway landscapes and alignments on drivers’ eye movement behavior and emergency reaction time, based on a driving simulator experiment. In this study, four simulation scenarios are evaluated including open space, semiopen space, semiclosed space, and enclosed space landscapes on highways in Yunnan Province, China. Twenty-four experienced drivers participated in a 6-kilometer driving experiment in each landscape scenario. Each subject was required to drive at 80 km/h in the scenarios and the driving behavior data were collected. Three different data analysis methods were employed: (1) descriptive analysis of the characteristics of drivers’ visual fixation area; (2) statistical tests of emergency reaction time with drivers’ demographic characteristics, highway landscapes, and alignments; and (3) multiple linear regression analysis of emergency reaction time, highway landscapes, and alignments. The results show that emergency reaction time is significantly influenced by highway landscapes and alignments, and the multiple linear regression model built in this experiment could accurately predict drivers’ emergency reaction time in different highway landscapes and alignments. Document type: Article
Abstract
This study aims at investigating the effects of highway landscapes and alignments on drivers’ eye movement behavior and emergency reaction time, based on a driving simulator [...]
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