Coupled human body and side impact model to predict thoracic response

Low density polyethylene, expanded polystyrene and expanded polypropylene: Strain rate and size effects on mechanical properties

“…The sensitivity of a material to deformation rate may also depend on the material density [2,7]. The rate dependency of polymeric foams is attributed to the viscoelastic properties of the base material, cell collapse or rupture, locking mechanisms that may occur between adjacent deforming cells, movement of gas (air) within the foam, and frictional forces.…”