Modeling of large inelastic deformations of foams with respect to the point of compaction

The present paper considers constitutive modeling of structural foams undergoing large deformations in combination with high deformation rates. In particular, large inelastic compactions is in focus, involving hardening of the material as the point of compaction of the foam is approached, and rate dependent evolution of the plastic deformation. A phenomenological approach is adopted, where the foam is regarded as a gas-filled porous material formulated in the framework of Theory of Porous Media (TPM). In this framework, an elasto-viscoplastic model of Perzyna type is proposed. As an example of model application, an analysis of an impact test of a polymeric foam cube is presented, involving calibration of the model parameters as well as the actual simulation of the impact test using the finite element code LS-DYNA.