Determination of Relaxation Moduli and Poisson‘s Ratio in Uniaxially Loaded Solid Polyethylene Foam Specimens as Part of Full Material Characterization

Abstract

The mechanical behavior of a solid polyethylene foam is characterizedby a constitutive equation which is of second order in the linearstrain tensor. It turns out that for the determination of the sixtime dependent material functions relaxation tests intension/compression, torsion and, for instance, in isotropic tension andcompression are necessary. For tension/compression tests theexperimental procedure is described in detail. Main emphasis is givento the methods of optical deformation measurement techniques. Resultsfor the relaxation moduli in tension/compression and for the Poisson‘sratio are presented.