Description: The model for low-density foams previously available in Abaqus/Explicit assumed the Poisson's ratio of the material to be equal to zero. While this assumption provides a good representation of the behavior of foams under large compressive strains, it fails to capture the nonzero Poisson's ratio observed at small strains. The low-density foam model has now been enhanced to include Poisson effects to better capture the behavior of these materials in a large range of strains and strain rates.

The model requires as input the stress-strain response of the material for both uniaxial tension and uniaxial compression tests. Poisson effects are included by also specifying lateral strain data for each of these tests. Rate-dependent behavior is specified by providing the uniaxial stress-strain curves for different values of nominal strain rates. Both loading and unloading rate-dependent curves can be specified to better characterize the hysteretic behavior and energy absorption properties of the material during cyclic loading.