Damage mechanisms in short glass fibre reinforced thermoplastic during in situ microtomography tensile tests

Micromechanical modelling of short fibre reinforced thermoplastics requires identification of damage mechanisms and their kinetics as a function of their microstructure. A compact tensile machine has been designed to observe damage mechanisms during in situ microtomography tensile tests. 3D pictures of the gage length are presented at different levels of damage, from the initial state to the failure of the specimen. Fibre failure, damage at fibre ends, debonding and damage growth in the matrix have been identified as damage mechanisms for these materials. Vicinity between crossing fibres has been pointed out as microstructural configurations driving the damage mechanisms. An analysis of the damage evolution (density, morphology and orientation) allows to establish a macroscopic failure scenario, consistent with microscopic observations.