Finite element analysis of dynamic crushing behaviors of closed-cell foams based on a tetrakaidecahedron model

The cellular structures of closed-cell foams were modeled as tetrakaidecahedrons and their dynamic crushing behaviors were simulated by the finite element method. In the numerical simulation, all the tetrakaidecahedrons have the same sizes. Numerical calculations were carried out to investigate principally effects of different impacting velocities, relative densities and strain hardening moduli of solid materials on deformation modes, plateau stress and densification strain energy. Energy absorption capacities of foams were comprehensively described. Numerical results show that deformation modes are greatly affected by impacting velocity. Especially when the foams are subjected to high-velocity impact, the I-shaped mode can be observed near the impacting rigid platen, and this deformation mode propagates towards the supporting rigid platen. Relative density contributes to energy absorption capacity significantly. Densification strain energy varies parabolically with relative density. In addition, there is a linear relationship between the three parameters including impact velocity, relative density and ratio of hardening modul to elastic modul of solid material and the plateau stress respectively.