中文摘要：

应用有限元方法分析了基于十四面体模型的三维闭孔泡沫材料的动态力学性能。计算中所有十四面体具有相同的尺寸，主要研究了不同初始冲击速度、不同相对密度以及组成泡沫的机体材料的应变强化对泡沫材料的变形模态、平台力及密实化应变能的影响，尽可能全面地描述了泡沫材料的能量吸收特性。数值结果表明：冲击速度对泡沫模型的模态影响较大，特别受到高速冲击时，冲击端泡沫形成“I”形然后向支撑端传播；相对密度对能量吸收能力的贡献较大，密实化应变能随相对密度呈二次曲线变化；冲击速度、相对密度及机体材料的应变强化分别与坪应力呈线性关系。

英文摘要：

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.