Documents published in Scipedia

• Lightweight materials development for automotive engineering use. Manufacture and End of Life optimization through Life Cycle Assessment.

  H. Afonso González, J. Ibarretxe, E. Acha, U. Olaziregi Cuevas, A. Esnaola, A. Serras, A. Iturrondobeitia.

  Materiales Compuestos (2023). Vol. 08 - COMUNICACIONES MATCOMP21 (2022) Y MATCOMP23 (2023), (Núm. 1 - Caracterización - Sostenibilidad y Reciclaje), 19

  
  

  Abstract

  With fuel economy and lightweight design becoming ever more significant due to the current materials, resources and environmental crisis, the manufacture of polymer composites for automotive industry use has experienced a steady growth in the last years and is expected to keep growing in the coming years. This means that there is a vast range of different polymer composites available in the market, with their unique properties, manufacturing processes and materials imbedded in them, each with their own set of impacts on the environment throughout their whole life cycle. The end-of-life treatment of a composite determines a substantial fraction of its footprint on the planet, and advanced treatments, namely pyrolysis can be used to obtain high value added compounds such as hydrogen and other light fuels. This study aims to address and quantify the impacts associated with the manufacturing and end of life treatments of an experimental glass fibre mat reinforced thermoplastic composite and compare them with the impacts caused by materials currently used in the automotive industry. Life Cycle assessment methodology will be used to compare the environmental impacts of this new material with traditional glass fibre composites, natural fibre reinforced composites and other materials with similar mechanical properties.

  Abstract
  With fuel economy and lightweight design becoming ever more significant due to the current materials, resources and environmental crisis, the manufacture of polymer composites [...]

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• Design and manufacture of 3D printed cores for the integration of photovoltaic cells in sandwich panels

  I. Sukia, A. Esnaola, J. Aizpurua, W. Cambarau, J. Hernández, J. Aurrekoetxea

  Materiales Compuestos (2023). Vol. 08 - COMUNICACIONES MATCOMP21 (2022) Y MATCOMP23 (2023), (Núm. 2 - Fabricación y Aplicaciones Industriales - Sostenibilidad y Reciclaje.), 44

  
  

  Abstract

  Multifunctional sandwich panels that can lighten and generate electrical energy are strategic for many industrial sectors, such as electric vehicle roofs or drones. This work analyses the integration of crystalline silicon photovoltaic cells between the glass/epoxy skins and the core manufactured by 3D printing with a polyamide reinforced with short carbon fibres. 3D printing has enabled the development of lightweight and stiff cores, with integrated wiring and junction box housings within the sandwich structure, as well as facilitators for the skin infusion process. The core design, with ramps on the periphery, facilitates the lamination and impregnation flow in the infusion process and the re-coating operations after infusion. The results, comparing the performance of the sandwich panel with and without integrated photovoltaic cells, show that the effect on the mechanical properties of the sandwich panel is not very significant. The maximum force recorded under a complex bending-twisting load is 11% lower with cells, but no delamination phenomena were observed in any case. As for the penetration energies under quasi-static and impact loads, the energies recorded for structures with photovoltaic cells are 5% and 2% lower respectively.

  Abstract
  Multifunctional sandwich panels that can lighten and generate electrical energy are strategic for many industrial sectors, such as electric vehicle roofs or drones. This work [...]

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• Improvement of the impact behavior of forged composite plates reinforced with continuous fiber tapes

  U. Olaziregi, M. Baskaran, U. Morales, A. Esnaola, J. Aurrekoetxea

  Materiales Compuestos (Online first).

  
  

  Abstract

  The conception of structural components using thermoplastic composite materials faces a dilemma when selecting the material/manufacturing process pairing. Continuous fiber-reinforced composites offer the best properties, but their design freedom is limited to shell-type parts. On the other hand, manufacturing processes for discontinuous fiber, such as injection (LFT) and forging (GMT), allow the production of complex geometries, but their mechanical properties are substantially lower. In fact, LFT and GMT are important in the current automotive industry, but their applications are limited to semi-structural components or internally complex geometries whose functionality is more focused on function integration rather than supporting high mechanical loads. The hybridization of discontinuous fiber composites with continuous fiber materials presents itself as a promising approach to achieve a synergistic effect from both technologies. In this study, the impact behavior of glass fiber-reinforced polyamide forged plates (GMT) was characterized, along with their hybridization with unidirectional carbon reinforcements. In the first phase, the effect of the processing temperature was investigated, concluding that increasing the temperature promotes the compaction between the two materials, resulting in improved impact resistance. Specifically, a 14% increase was observed in both maximum force and dissipated energy. In the second phase, the effect of hybridization with unidirectional tapes as reinforcement was analyzed, showing the same positive effect. The hybridization led to a 20% improvement in maximum force and a 36% increase in dissipated energy.

  Abstract
  The conception of structural components using thermoplastic composite materials faces a dilemma when selecting the material/manufacturing process pairing. Continuous fiber-reinforced [...]

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• CUSTOMISED AND INTEGRATED SOLE FOR CYCLING MANUFACTURED BY 3D PRINTING OF CONTINUOUS CARBON FIBRE REINFORCED POLYAMIDE

  A. Esnaola, U. Morales, M. Iragi, L. Aretxabaleta, J. Aurrekoetxea

  Materiales Compuestos (Online first).

  
  

  Abstract

  Customised cycling soles are extremely complex to design and manufacture since the plantar pressure distribution and anatomical shape are specific for every foot. This paper explores the potential of topology optimisation and additive manufacturing of continuous fibre reinforced plastic. The highly abstract material distribution resulting from the topology optimization software was interpreted considering the additive manufacturing constraints for getting the detailed design. The selected printing strategy consisted of concentric fibre orientation to better fit load-paths, and the build-orientation aimed to maximise the fibre content, resulting in 30 hours for printing each sole. Regarding the specific stiffness at the hallux and the hell, the new soles are at least 60% higher. Therefore, it has been confirmed that the proposed approach is a powerful tool to design the cycling shoe adapted to the local stiffness of each foot.

  Abstract
  Customised cycling soles are extremely complex to design and manufacture since the plantar pressure distribution and anatomical shape are specific for every foot. This paper [...]

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• Energy absorption capacity of pre-homologated polyamides against fire for 3D-printing

  U. Morales, A. Esnaola, I. Sukia, U. Olaziregi Cuevas, J. Aurrekoetxea

  Materiales Compuestos (2024). Vol. 08 - COMUNICACIONES MATCOMP21 (2022) Y MATCOMP23 (2023), (Núm. 3 - Caracterización - Daño, Fractura y Fatiga), 3

  
  

  Abstract

  Recent advances in developing new concepts for railway structures demand new lightweight structure concepts not only to reduce their energy consumption but also to reduce the load transmitted to the rail track. Fibre-reinforced polymers (FRP) have gained attention in the railway industry due to their lightweight properties, specific strength and stiffness, and corrosion resistance. Most published studies on the design of lightweight structures, for body and rolling stock, focus on continuous fibre-reinforced thermoset polymers (cFRP). However, derailment risk and fire safety must never be compromised due to this weight-reduction process.   Therefore, new structure designs must be impact resistant and the materials must comply with EN-45545-2. A wide variety of fire protection, self-extinguishing or flame retardant systems for composite components and structures are available in the literature. The influence of flame retardant loading on the impact properties of a continuous carbon fibre reinforced polyamide 6 manufactured by 3D printing of continuous carbon fibre prepregs (FFF) has been analysed in the present work. The impact characterisation of a sandwich panel with a bio-inspired cellular core was carried out in this study. From the results, it has been concluded that the pre-homologated materials (Onyx-FR and cCF/PA-FR) have a similar energy absorption capacity (EAS) to that of the reference reinforced polyamide 6 used in 3D printing processes - FFF.

  Abstract
  Recent advances in developing new concepts for railway structures demand new lightweight structure concepts not only to reduce their energy consumption but also to reduce [...]

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