Dynamic compressive strength and crushing properties of expanded polystyrene foam for different strain rates and different temperatures

In this study, static and dynamic compression and crushing tests were conducted on expanded polystyrene (EPS) foam for material characterisation at high strain rates. This was done to obtain the stress-strain curve for different temperatures and densities. An influence of the strain rate on the experimental data was shown. The resulting curves for modelling were extracted from the experimental data, which were obtained from high speed drop tower tests. The methodology for the processing of the experimental data for use in the finite element (FE) modelling was presented. The foam material model of LS-Dyna was used to simulate the dynamic compression process. This model is dedicated to modelling crushable foam with optional damping, tension cut-off, and strain rate effects. The adjustment of the material parameters for successful modelling has been reported. This FE model of EPS foam was validated with experimental data using impact on a “kerbstone” support. This model can be applied for simulation of dynamic loads on a bicycle helmet. It is useful for designing a reliable bicycle helmet geometry for different types of accidents.