Phase field study on fracture behavior of crushable polymer foam

•The “crushable foam” model is combined with the phase field method to describe the fracture behavior of polymer foam materials.•The model considers the compaction characteristics and the asymmetry of tension and compression of porous materials.•The numerical stability and effectiveness of the phase field model are illustrated by simulating the uniaxial tensile fracture and the pure shear fracture.•The initiation, propagation, branching, and merger of cracks in porous foam material under complex loading are reproduced by using the proposed model. Polymer foam is a widely used material across various industries for its lightweight and exceptional energy absorption capability. Nevertheless, its porous structure and compaction properties present challenges in simulating crack initiation and propagation. The phase field method has attracted much attention for its advantages in predicting cracks. In this paper, we combine the phase field method with the “crushable foam” model and introduce the modified Drucker-Prager failure criterion to establish the phase field model of polymer foam materials. Material parameters are calibrated using experimental data from uniaxial compression, uniaxial tensile and shear punching experiments. The typical tensile, shear and compression instability fracture processes of polyurethane are then simulated using the proposed model, and the numerical results agree well with the experimental results. This indicates that the coupled phase-field crushable foam model not only exhibits the compaction properties of polymer foam materials but also accurately predicts its crack propagation under complex loading. Studying the fracture behavior of polymer foams under complex loads can enhance their engineering applications.