DEFORMATION AND ENERGY-ABSORPTION OF POLYMER FOAMS AS A FUNCTION OF 2-D INDENTER AND ABSORBER GEOMETRIES

Two-dimensional indenters (flat plate and cylinder) were used to compr ess rectangular and trapezoidal foam energy absorbers as a function of polymer, foam density, and thickness. An increased deformation volume formed when the indenter contact area was less than the foam absorber area, resulting in both increased energy absorption and stress transm itted to the indenter (i.e., ''load spreading''). The deformation volu me was trapezoidal, not prismatic, and was characterized by the indent er geometry, dimensions, and foam thickness. Conservative energy absor ber design can be achieved by using ''energy absorption diagrams'' tha t account for the indenter (i.e., product) and absorber geometry and d egree of load spreading.