Prediction of damage in randomly oriented short-fibre composites by means of a mechanistic approach

A micro-macro mechanistic approach to damage in short-fibre composites is developed in this paper. At the micro-scale, the damage mechanisms such as matrix cracking and fibre/matrix debonding are analysed to define the associated damage variables. The stiffness reduction law dependent on these variables is then established using micromechanical models and average orientation distributions of fibres and microcracks. The macroscopic response is obtained by means of thermodynamics of continuous media, continuum damage mechanics and a finite element formulation.