On the rate-dependent behavior of open-cell polymeric foams in uniaxial compression

This paper describes some uniaxial compression experiments on polyurtehane foams, and the rheological model proposed to describe the observed response. The response exhibits some peculiar features: strain localization, stress softening, rate dependence, and memory effects. While strain localization can be described in the context of nonlinear elasticity, the other phenomena are intrinsically viscoelastic. In the proposed model, the foam is represented as a chain of elements, each of which consists of an elastic spring with nonconvex strain energy, connected in parallel with a viscoelastic damping element. The results of some preliminary numerical simulations are given.