Predictions of carbon fibre sheet moulding compound (CF-SMC) mechanical properties based on local fibre orientation

A non-deterministic multiscale methodology is proposed to predict variability in longitudinal tensile stiffness and strength of unidirectional composite plies. Local composite strength and stiffness are predicted at the microscale and assigned to finite elements models, which represent the material at the scale of a ply. In doing so, fibre volume fraction variations and fibre misalignment are accounted for. The local strength is computed using a fibre break model able to reproduce the onset and accumulation of the fibre breaks at the microscale. A large number of simulations were performed at both scales to study the convergence of the mean values of strength and the variability. It is shown that the local volume fraction variation has a major role in the material failure prediction, while very small misalignment can be considered negligible.status: publishe