Prediction of bulk mechanical properties of PVC foam based on microscopic model:Part I-Microstructure characterization and generation algorithm

Abstract

The mechanical properties of porous materials greatly depend on their microstructures, so the generation of realistic microstructures is the premise for a sound numerical simulation and analytical prediction. This paper presented the microstructure generation of three kinds of transversely isotropic closed-cell polyvinyl chloride (PVC) foams with different densities based on the geometric characteristics obtained from the X-ray computed tomography (CT) technology. Advancing front method was used to densely pack a set of spheres whose volume distribution is proportion to the cell volume distribution and the microstructure was formed by Laguerre tessellation. Then the geometric characteristics of the numerical models were compared with those from the CT. The good consistence proves that the proposed method is accurate and efficient to produce the representative microstructure of the PVC foams. Finally, a method was proposed to optimize the microstructure of small size numerical specimens, by which the small specimens could give similar geometric characteristics to those of the large specimens.