Numerical simulation of the damage behavior of bidirectionally reinforced ceramic cross-ply laminates

The behavior of bidirectionally reinforced SiC/SiC cross-ply laminates is s tudied with the help of numerical simulations based on the finite element m ethod (FEM). Within the presented model the composite is regarded on the la yer scale considering each layer as homogeneous with 'layer properties'. Br ittle cracking as well as damage effects can appear within each layer, whic h is why both a damage and a fracture model for the plies is derived. The d amage model is based on damage variables depending on the strain state. Fra cture is checked using a fracture criterion, a crack and a post-failure mod el. In this way fracture can be considered for multiaxial stress states and the statistical distribution of strength values as well as load transfer e ffects after crack initiation can be taken into account. By subjecting the structure to a cooling down process before mechanical loading in one of the fiber directions the residual thermal stresses within the layers can also be regarded. The purpose of the simulations is to indicate the influence of important parameters on the composite behavior.