The determination of a constitutive equation for polystyrene bead foam.

Abstract

Polystyrene Bead (PSB) foam is often used as an energy dissipator to reduce the likelihood of serious injury to motor vehicle passengers during accidents. The purpose of this study was to investigate and model the behaviour of PSB foam subjected to quasi-static and dynamic deformation. A wide range of tests was conducted. By factoring into separate functions the effects of thickness, density, strain, and initial and instantaneous strain rate, the response of the foam can be simulated. The resulting constitutive equation can be used to accurately describe both the quasi-static and the dynamic deformation responses. The validity of the model is demonstrated with experimental data. The behaviour of PSB foam is briefly discussed in relation to the biomechanics of head injury.