通过编织Kevlar/Epoxy复合材料层合板的平头弹冲击实验,分析了结构在不同冲量下的变形失效模式以及结构的抗冲击性能。实验表明复合板的变形失效模式主要表现为:(1)弹性变形;(2)复合板表面嵌入失效及整体塑性大变形;(3)背面纤维拉伸断裂及分层失效。基于实验研究,运用LS-DYNA 971有限元程序对铺层数不同的复合板在冲击载荷作用下的动态响应过程进行了数值模拟,模拟结果与实验吻合较好,子弹作用区域边缘处首先发生近似圆形的嵌入失效,而在板背面发生近似正方形的破坏区域;计算中重点分析了铺层数对结构动力响应的影响,在一定冲量范围内,通过对铺层数的优化,能够有效地减小后面板挠度,提高结构的能量吸收效率,增强结构的抗冲击性能。
Based on the blunt projectile impact test of woven Kevlar/Epoxy composite laminates, the deformation and failure modes of the composite laminates subjected to impact load were analyzed. Ex- perimental results show that the deformation and failure behaviors were exhibited in the following ways., the global elastic deformation, the global plastic deformation with local embedded failure on the front surface, and the delaminated failure with fibers tension fracture on the back surface. The finite element software LS-DYNA 971 was employed to analyze the dynamic response of the woven Kevlar/ Epoxy composite laminates subject to impact loading. Numerical simulation results show that there is a good agreement of the deformation/failure modes and the back face center-point deflection of the specimens, with those of the experimental results. The failure area on the front face is a circle embed- ded region, but a square failure region on the back face. The numerical simulation is focused on stud- ying the effects of the number of layers on the dynamic response of the structure. Optimizing the number of the layers can effectively reduce the permanent deflection, increase the energy absorption efficiency and improve the impact resistance performance of the structure within a given range of im- pulses.