Behavior pattern and parametric characterization for low density crushable foams

Crushable foams may be used for shock mitigation and impact absorption applications that take advantage of their complex compression behavior. It is highly desirable that their constitutive behavior be characterized by suitable models with meaningful parameters such as Young's modulus for linear elasticity. This work describes constitutive behavior patterns and parametric characterization for low density crushable foams. Compression tests under large deformation were conducted on polyurethane foams of different densities. Various behavior patterns were observed that differ from the well-known three-stage behavior for porous materials. A set of multi-parameter models was proposed to parametrically characterize the behavior patterns. The constitutive model was intended to serve as a framework for crushability characterization.