Documents published in Scipedia

• New analytical models for non-symmetric Double Cantilever Beam and End-Notched Flexure tests

  F. Mujika, A. Arrese, J. Gracia, A. Boyano

  Materiales Compuestos (2024). Vol. 08 - COMUNICACIONES MATCOMP21 (2022) Y MATCOMP23 (2023), (Núm. 3 - Caracterización - Daño, Fractura y Fatiga), 5

  
  

  Abstract

  The fundamentals of new analytical models based on energy and coenergy of deformation are explained to analytically address asymmetric interlaminar fracture tests. After reviewing some concepts of laminated beam theory, the energy release rate as a function of coenergy is determined from a global point of view, including in an unprecedented way the contribution of hygrothermal stresses. On the other hand, after the determination of the J integral in the cohesive zone, the conditions required for the asymmetric fracture tests to occur in pure mode in linear elastic fracture are explained, based on the forces and displacements of the crack tip. Furthermore, knowing these forces and displacements, it is possible to determine the energy release rate that corresponds to each fracture mode.

  Abstract
  The fundamentals of new analytical models based on energy and coenergy of deformation are explained to analytically address asymmetric interlaminar fracture tests. After reviewing [...]

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• Analytical approach for two-plane bending applied to unidirectional composite plates

  U. Garitaonaindia, N. Carbajal, M. Isasa, F. Mujika

  Materiales Compuestos (2024). Vol. 08 - COMUNICACIONES MATCOMP21 (2022) Y MATCOMP23 (2023), (Núm. 3 - Caracterización - Daño, Fractura y Fatiga), 2

  
  

  Abstract

  In this work, a new analytical procedure is developed to obtain the displacement field of a unidirectional composite plate subjected to bending in two planes. The analysed configuration consists of a plane plate supported at four points to which a point force is applied at the centre. The calculation procedure is based on the strain energy. The effects created by bending moments, torsional moments and shear forces in the plate have been considered. The results obtained analytically have been validated by comparing them with existing literature and with numerical simulations performed with the finite element software ABAQUS. High correlations have been obtained for the values corresponding to the vertical displacements in different alignments of points belonging to the plate, however, the same has not occurred with the distribution of moments.

  Abstract
  In this work, a new analytical procedure is developed to obtain the displacement field of a unidirectional composite plate subjected to bending in two planes. The analysed [...]

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• Two-plane bending test applied to unidirectional composite laminates

  U. Garitaonaindia, N. Carbajal, M. Isasa, F. Mujika

  Materiales Compuestos (2022). Vol. 07 - COMUNICACIONES MATCOMP21 (2022), (Núm. 2 - Aplicaciones Industriales - Caracterización), 178

  
  

  Abstract

  This paper analyses the two-plane bending test to characterise the behaviour of unidirectional composite laminates. This test consists of a flat plate supported at four points to which a point force is applied at the centre. Currently, this configuration is not mathematically solved for orthotropic materials. Initially, the displacements and bending moments produced in plates of isotropic material have been analysed by means of numerical simulation and analytical approach. The results obtained have been corroborated with other works published in the scientific literature. Subsequently, the numerical models and the analytical development have been applied to plates formed with orthotropic material, in the configuration of the two-plane bending test. For this purpose, rectangular plates with different aspect ratio have been analysed in order to obtain different stress ratios along the fibre and perpendicular to it. Finally, the results obtained both by numerical simulation and by the analytical approach have been compared with experimental tests carried out on unidirectional composite specimens made of epoxy matrix and carbon fibre.

  Abstract
  This paper analyses the two-plane bending test to characterise the behaviour of unidirectional composite laminates. This test consists of a flat plate supported at four points [...]

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• Descomposición en modos en ensayos de fractura interlaminar y de uniones adhesivas con brazos de grieta asimétricos

  F. Mujika

  Materiales Compuestos (2023). Vol. 08 - COMUNICACIONES MATCOMP21 (2022) Y MATCOMP23 (2023), (Núm. 1 - Caracterización - Sostenibilidad y Reciclaje), 28

  
  

  Abstract

  Las pruebas de flexión con entalla final y viga en doble voladizo se diseñaron para caracterizar la fractura interlaminar de materiales compuestos en modos puros I y II. En ambos casos, los especímenes tienen una longitud de fisura inicial en la mitad del espesor. En el caso de especímenes bimaterial, si la grieta está ubicada en el medio del espesor, el modo mixto podría existir, debido a la asimetría material. El objetivo del presente estudio es proponer relaciones geométricas para obtener condiciones de modo puro cuando se ensayan especímenes bimateriales en configuraciones DCB y ENF.

  Abstract
  Las pruebas de flexión con entalla final y viga en doble voladizo se diseñaron para caracterizar la fractura interlaminar de materiales compuestos en modos puros [...]

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• Determination of the flexural and shear moduli in curved section specimens by means of bending tests

  I. Adarraga, F. Mujika, F. De Caso

  Materiales Compuestos (2022). Vol. 07 - COMUNICACIONES MATCOMP21 (2022), (Núm. 2 - Aplicaciones Industriales - Caracterización), 177

  
  

  Abstract

  In recent years, wooden and concrete poles are replacing by others made of fiberglass-reinforced polyester. The advantages of this material compared to traditional ones are its low weight, ease of transport and resistance to corrosion, fire and weather. Due to the great variability in the mechanical properties provided by manufacturers, it may be useful to define a bending test procedure to characterize the material using specimens obtained from poles. Since these specimens have a curved section, it is necessary to analyze the influence of shear when the width and length of the specimen vary. In this study, the effect of shear is analyzed to obtain the flexural and shear moduli by means of bending tests with different lengths of the specimen.

  Abstract
  In recent years, wooden and concrete poles are replacing by others made of fiberglass-reinforced polyester. The advantages of this material compared to traditional ones are [...]

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