Experiments on Elastic Polyether Polyurethane Foams Under Multiaxial Loading: Mechanical Response and Strain Fields

We study experimentally the mechanical response of elastic polyether polyurethane (EPP) foams up to large strains over the range of commercially available densities and for a variety of loading conditions. To this end, we subject the foams in a set of EPP foams to five different tests, namely, compression along the rise direction, compression along a transverse direction, tension along the rise direction, simple shear combined with compression along the rise direction, and hydrostatic pressure combined with compression along the rise direction. The set of EPP foams consists of foams of five apparent densities ranging from $50.3kg/m3$ to $221kg/m3$⁠. For each test and foam density, we report the mechanical response in the form of a stress-strain curve or a force-displacement curve. For some tests and foam densities, we use a digital image correlation method to measure the strain field on the surface of the foam. In a discussion of our experimental results, we put emphasis on the relation between the stress-strain or force-displacement curve recorded in a test and the attendant strain fields.