A CAE based procedure to predict the low velocity impact response of a composite CAI specimen

The integrated procedure allowed to obtain a better understanding of the influence of some numerical parameters on the simulation results

ABSTRACT

The residual strength, in particular the compression strength after damage due to low velocity impact, is one of the most critical issue for composite laminates. Indeed, composite structures submitted to low energy impacts reveal a brittle behavior and can undergo significant damage in terms of matrix cracks, fiber breakages and delaminations. Such damage is particularly dangerous because it may be undetectable by visual inspection and can drastically reduce the pristine mechanical characteristics of the structure. Generally the behavior of composite materials with respect to this issue is experimentally evaluated by the standard CAI (Compression After Impact) test. For this reason, in order to simulate the impact event, an LS-DYNA FE model of this test was developed and coupled with modeFRONTIER. The integrated procedure allowed to obtain a better understanding of the influence of some numerical parameters on the simulation results (sensitivity analysis), moreover the configuration which provided the best agreement with the experimental data (optimization analysis) was computed.