A void growth- and coalescence-dependent anisotropic damage model for polymeric foams

Abstract

We present an elastic damage constitutive model for polymeric foam based on thermodynamics framework to consider the effects of anisotropy and the growth and coalescence of cavities. The evolution equation of the proposed model describes the material behavior sustaining anisotropic and unilateral damage. To carry out finite element analysis, the material properties for various polymeric foams are applied to the proposed damage model; we thus implement the proposed damage model in the commercial finite element program as a user-defined material subroutine. In order to validate the proposed anisotropic damage model, the numerical results are compared to the results of a series of tensile and compressive tests on various polymeric foams. Additionally, we propose the failure criterion for this damage model as based on the mass-dependent energy per unit mass at failure. The developed damage model can be used for further research on damage mechanics and finite element analysis of polymeric foams in continuum mechanics.