Unloading response prediction of indentation loaded foam core sandwich structures using extended foam material model with tensile hardening

Prediction of the residual state of sandwich structures after impact or indentation loading is important for estimation of their residual properties and for damage detection purposes. An extended foam material model, that takes into account the degradation of elastic modulus during compression and the changed tensile response after compressive damage of the foam material, was constructed based on the Crushable foam material available in ABAQUS. The model was validated by foam core sandwich beam indentation simulation and comparison with experimental data. The extended model could predict the indentation loading and unloading response accurately and provided improved predictions of the residual state.