Test methodModelling of the strain rate dependent deformation behaviour of rigid polyurethane foams

Rigid polymer foams exhibit excellent mechanical properties for the use in impact and crash components of lightweight structures, such as core layer of sandwich-structures. The design of these lightweight structures strongly depends on secured knowledge of the stress-strain response at various strain rates. For the purpose of predicting the strain rate dependent behaviour under compression loading, an analytical model based on a Burgers model was developed and validated with comprehensive experimental tests of a rigid closed-cell polyurethane foam with different densities (230 kg/m3, 420 kg/m3 and 610 kg/m3) using a servo-hydraulic high speed testing machine at defined strain rates, ranging from 0.0004 s−1 to 8 s−1.