High-fidelity computational micromechanics of first-fibre failure in unidirectional composites: Deformation mechanisms and stress concentration factors

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:204

Article

Barzegar, Mostafa^1,2  Costa, Josep⁴  Lopes, Claudio S.^1,3 

[1] IMDEA Mat Inst, C Eric Kandel 2, Madrid 28906, Spain

[2] Univ Politecn Madrid, Dept Ciencia Mat, Madrid 28040, Spain

[3] Luxembourg Inst Sci & Technol, 5 Ave Hauts Fourneaux, L-4362 Esch Sur Alzette, Luxembourg

[4] Univ Girona, Polytech Sch, AMADE, Girona 17073, Spain

关键词: Composite materials;    Computational micromechanics;    Stress concentration factors;    Fibre breakage;    Fibre/matrix interface debonding;   

DOI  :  10.1016/j.ijsolstr.2020.08.005

来源: Elsevier

【 摘 要 】

Stress redistribution and damage phenomena in the vicinity of the first-fibre break in unidirectional composites under longitudinal tensile loads are investigated by means of high-fidelity computational micromechanics based on experimentally characterised material constituents. In this framework, periodic microstructures with statistically representative random fibre packings are analysed, and transient dynamic analyses are performed to take into account the progressive failure and recoiling of a breaking fibre. The effects of mechanisms such as curing residual stresses, fibre/matrix debonding and matrix inelastic deformation on the first-fibre failure process are investigated. The stress concentration factors on intact fibres are found to depend on the statistical failure stress of the breaking fibres, and decrease with increasing strength. For the AS4/8552 composite with average constituent properties, maximum stress concentration factors of 20.6%, 16.1% and 14.2% are predicted, respectively, for fibre volume fractions of 50%, 60%, 70%. Material systems with lower fibre-to-matrix stiffness ratios, such as glass/epoxy, result in lower stress concentration factors. The fibre/matrix interface strength is found to have a limited overall influence on stress redistribution around fibre breakage. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

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