Generation and homogenization of foamed polymer RVEs: microstructure-mechanical properties relationship
Résumé
The main purpose of this study is to better understand the relationship between the microstructure of foamed polymer and mechanical properties. X-Ray tomography was performed on polypropylene foam specimens machined from injected plates. These plates were obtained for different thicknesses and exhibit different microstructure morphologies. The tomography scans were first digitalized and meshed. Then, numerical simulations were performed on representative volume elements (RVEs) to get homogeneous mechanical property of the material using a parallel C++ library Cimlib developed at CEMEF. Numerical methods described in this study focused on immerged or body-fitted strategy (FE context - level set framework - meshing adaptation) for exact and statistical RVEs generation. The numerical results were compared to experimental testing performed under tension and compression at different strain rates using image correlation. Good agreement was observed between simulations performed at the mesoscale and experimental tests carried out at the macroscale for both real and statistical RVEs. This methodology opens a way for the development of digital materials designed for specific mechanical properties.