Energy absorbability of foamed rigid polyurethane was studied by static compression and impact tests on knee and head models with the shapes prescribed in MVSS (Motor Vehicle Safety Standard in U.S.A.). The following results were obtained.
(1) Foamed rigid polyurethane absorbs much energy in a manner similar to ductile materials.
(2) The MVSS for the knee model is satisfied by a foamed rigid polyurethane with the density of 0.075g/cm3 and the thickness of 120mm, and the MVSS for the head model is satisfied by the one with 0.04g/cm3 density and 80mm thickness.
(3) No dependence of deformation behavior and energy absorbability of foamed rigid polyurethane on the deformation rate was observed.
(4) The compressive load F and absorbing-energy E in knee model or head model tests can be described simply as follows;
where σp is the plateau stress obtained by the flat indenter test, l is an indentation depth of the knee model or the head one, and S is the cross section of the indenter perpendicular to the direction of a compressive load.