Mechanical behaviour of EPS foam under combined compression-shear loading

Abstract

Finite Element Analysis (FEA) has been used to investigate the deformation response of EPS foam under different quasi-static and dynamic loading conditions, combining compression and shear. All numerical simulations were performed using commercial finite element software. The compressive and shear forces within the EPS foam during the loading process were predicted by the numerical simulations, and these were validated against experimental results performed previously. The experimental results indicated that, under combined compression and shear loading, the shear deformation of the EPS foam material tends to decrease its compressive strength compared with that under pure compression. Both compressive and shear stress at yield also showed strain-rate effects under dynamic combined compression and shear loading. The numerical predictions agree well with experimental results at the early stage of deformation under quasi-static loading conditions, but less well under dynamic loading conditions, albeit the forces at yield were predicted with relative accuracy. This indicates that constitutive models for crushable foam that are currently incorporated into finite element models need to be refined in future to obtain better predictions.