ABSTRACT
In this study, three-dimensional homogeneous finite element analysis of truncated octahedral unit cells consisting of hyperelastic beams were conducted to predict macroscopic mechanical characteristics of polyurethane foam while considering its microscopic structure. Homogenization theory was applied to original finite element analysis code, and unit cells for simulation were assumed to be subject to periodic boundary conditions. The relative density of homogenization analysis was adjusted based on the width of the beams in the unit cell model. The polyurethane matrix was assumed to be represented by incompressible hyperelasticity. The Mooney-Rivlin model and incompressible condition were applied to this hyperelasticity. The material parameters of the Mooney-Rivlin model for the polyurethane matrix were identified with the tensile loading test results. Furthermore, compression tests on polyurethane foam with various relative densities were conducted to verify the applicability of the analysis. The analysis results had good agreement with the compression test results.
