The Experts below are selected from a list of 30 Experts worldwide ranked by ideXlab platform
Frank R. Jones - One of the best experts on this subject based on the ideXlab platform.
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The effect of temperature on stress transfer between a broken Fibre and the adjacent Fibres in unidirectional Fibre composites
Composites Science and Technology, 2008Co-Authors: Shabnam Behzadi, Frank R. JonesAbstract:Abstract The effect of yielding of a polymer-matrix on stress transfer between a broken Fibre and an adjacent Fibre has been studied using a three-dimensional (3D) finite element model. The full stress–strain curves of Araldite MY0510 epoxy resin have been measured as a function of temperature. The elasto-plastic behaviour of the epoxy resin has been included in a 3D multi-Fibre FE model. The yielding of the matrix affects the axial strain development along both the fractured and the Neighbouring Fibre. The intensified axial strain at the intact Neighbouring Fibre has been found at the immediate radial distance from the broken Fibre. Strain concentration factor (SCF) of the nearest Neighbouring Fibre decreased as a result of an increase in temperature.
Sung Kyu Ha - One of the best experts on this subject based on the ideXlab platform.
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Geometrical range of microscopic stress distribution change due to Fibre array irregularities for thermally and transversely loaded CF/epoxy composites
Plastics Rubber and Composites, 2020Co-Authors: Masaki Hojo, Masaaki Mizuno, Thomas Hobbiebrunken, Taiji Adachi, Mototsugu Tanaka, Sung Kyu HaAbstract:A detailed numerical investigation has been carried out to investigate the effect of local Fibre array irregularities on microscopic interfacial normal stress for transversely loaded unidirectional carbon Fibre/epoxy composites with random Fibre arrangement. Linear elastic finite element analyses were carried out for a two-dimensional image based model composed of 70 Fibres. One Fibre in this image based model is replaced with resin as the resin equivalent Fibre, and the resulting change in microscopic interfacial normal stress distribution is investigated. Three Fibres are selected for the resin equivalent Fibres to clarify the individual local geometrical irregularity. Calculations were carried out for three loading conditions: case A, cooling of -155 K from the curing temperature; case B, transverse loading of 75 MPa chosen as an example of macroscopic transverse fracture strength and case C, both cooling from the curing temperature and transverse loading of 75 MPa. The effect of Fibre array irregularities on the interfacial stress state is limited to the region between the resin equivalent Fibre and its first Neighbouring Fibres. The contribution of the second Neighbouring Fibre is small and that of further Fibres is negligible.
Warren Hepples - One of the best experts on this subject based on the ideXlab platform.
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Influence of voids on damage mechanisms in carbon/epoxy composites determined via high resolution computed tomography
Composites Science and Technology, 2014Co-Authors: A.e. Scott, Ian Sinclair, S.m. Spearing, Mark Mavrogordato, Warren HepplesAbstract:A multi-scale computed tomography (CT) technique has been used to determine the material structure and damage mechanisms in hydrostatically loaded composite circumferential structures. Acoustic emission sensing was used to locate macroscopically regions of high damage under load to inform the computed tomography. The resultant images allow direct three-dimensional analysis of voids, Fibre breaks and cracking, for which a high level of confidence can be placed in the results when compared to other indirect and/or surface-based methods. Ex situ analysis of loaded samples revealed matrix cracking in the longitudinally wound plies, whilst Fibre breaks were observed in the circumferentially wound plies. The matrix cracking within the longitudinally wound plies is shown to interact directly with intralaminar voids. The correlation of voids with Fibre breaks in the circumferentially wound plies is less distinct. A three-dimensional tessellation technique was used to analyse the spatial distribution of the voids and to compare with single Fibre break locations. Whilst there was no first order correlation between Fibre break densities and void volume fractions or void dimensions, a distinct correlation was found between voids and nearest Neighbouring Fibre breaks, where 2.6-5 times more Fibre breaks occurred immediately adjacent to a void than would be expected for randomly distributed breaks. (C) 2013 Elsevier Ltd. All rights reserved.
Shabnam Behzadi - One of the best experts on this subject based on the ideXlab platform.
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The effect of temperature on stress transfer between a broken Fibre and the adjacent Fibres in unidirectional Fibre composites
Composites Science and Technology, 2008Co-Authors: Shabnam Behzadi, Frank R. JonesAbstract:Abstract The effect of yielding of a polymer-matrix on stress transfer between a broken Fibre and an adjacent Fibre has been studied using a three-dimensional (3D) finite element model. The full stress–strain curves of Araldite MY0510 epoxy resin have been measured as a function of temperature. The elasto-plastic behaviour of the epoxy resin has been included in a 3D multi-Fibre FE model. The yielding of the matrix affects the axial strain development along both the fractured and the Neighbouring Fibre. The intensified axial strain at the intact Neighbouring Fibre has been found at the immediate radial distance from the broken Fibre. Strain concentration factor (SCF) of the nearest Neighbouring Fibre decreased as a result of an increase in temperature.
Masaki Hojo - One of the best experts on this subject based on the ideXlab platform.
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Geometrical range of microscopic stress distribution change due to Fibre array irregularities for thermally and transversely loaded CF/epoxy composites
Plastics Rubber and Composites, 2020Co-Authors: Masaki Hojo, Masaaki Mizuno, Thomas Hobbiebrunken, Taiji Adachi, Mototsugu Tanaka, Sung Kyu HaAbstract:A detailed numerical investigation has been carried out to investigate the effect of local Fibre array irregularities on microscopic interfacial normal stress for transversely loaded unidirectional carbon Fibre/epoxy composites with random Fibre arrangement. Linear elastic finite element analyses were carried out for a two-dimensional image based model composed of 70 Fibres. One Fibre in this image based model is replaced with resin as the resin equivalent Fibre, and the resulting change in microscopic interfacial normal stress distribution is investigated. Three Fibres are selected for the resin equivalent Fibres to clarify the individual local geometrical irregularity. Calculations were carried out for three loading conditions: case A, cooling of -155 K from the curing temperature; case B, transverse loading of 75 MPa chosen as an example of macroscopic transverse fracture strength and case C, both cooling from the curing temperature and transverse loading of 75 MPa. The effect of Fibre array irregularities on the interfacial stress state is limited to the region between the resin equivalent Fibre and its first Neighbouring Fibres. The contribution of the second Neighbouring Fibre is small and that of further Fibres is negligible.
