Microstructural Effects on the Static and Dynamic Mechanical Properties of Polyurethane Foam

ABSTRACT Artificial cartilage foam (ACF) is a novel polyurethane foam, characterized by a pore structure that is partially connected and partially closed. The present study proposes a novel mesoscale model with mixed cellular pores, and investigates the effects of parameters such as strain rate of the soft matrix, air, and interconnectivity between pores on the mechanical properties of foam materials. The research reveals that the strain rate effect of the cellular foam matrix significantly enhances the plateau stress of the foam material under high‐speed compression. Additionally, it is demonstrated that the connectivity and pore size parameters have a noticeable influence on the mechanical performance of the matrix mixed cellular foam materials. Furthermore, the investigation extends to the internal development of the material under both high‐speed and static compression, a phenomenon that is difficult to observe experimentally. The study finds that the different stress plateau regions caused by dynamic and static compression are primarily due to pore deformation, and the deformation sequence of the pores is related to their spatial positions, with pores located in the damage zone being more likely to deform. Finally, under high‐density conditions, the soft matrix results in increased lateral deformation, forming a horizontal densification zone. The methods and conclusions of this study can be applied to material design in the materials industry, providing guidance for the production of polymer foam materials.