冲击波和破片群联合作用下高强聚乙烯/泡沫铝夹芯复合结构毁伤响应特性

Damage Response Characteristics of UHMWPE/aluminum Foam Composite Sandwich Panel Subjected to Combined Blast and Fragment Loadings

为提高舰船在冲击波和破片群联合作用下抗毁伤能力,提出一种新型高强聚乙烯/泡沫铝夹芯复合结构,旨在采用TNT炸药和预制破片的方式开展其在联合作用下毁伤响应的数值研究。基于有限元软件LS-DYNA,模拟结构在冲击波和破片群联合作用下的动态响应过程,与典型工况的实验结果对比验证数值模型的可靠性。在此基础上,分析特征点的速度与加速度响应以及能量吸收特性,获得结构的毁伤响应特征,进一步探讨面板厚度配置对结构失效模式和塑性变形的影响。结果表明:夹芯复合结构加速度时程曲线中破片和上面板中心点加速度均存在两个明显的峰值,分别是由于破片撞击强度较大的上面板和高强聚乙烯芯层所引起;上面板和泡沫铝在复合结构整体塑性耗散功中占主导;等质量条件下,上下面板等厚的配置在上面板对于破片的速度衰减能力减弱不大情况下,下面板具有足够强的抗弯能力,使得下面板塑性变形最小,具有最优的抗联合毁伤性能。

A novel composite sandwich panel with UHMWPE and aluminum foam cores is proposed.The damage mechanism of composite sandwich panel under the combined blast and fragment loading is studied by using LS-DYNA software.The synergetic effects of blast and fragment loadings were achieved by attaching the pre-fabricated fragments to the bottom surface of the cylindrical TNT explosive.The proposed numerical model was validated by comparing the simulated results with the existed experimental data.Based on the calibrated numerical model,the whole dynamic response process,velocity and acceleration response at feature point,as well as the energy dissipation characteristics for the composite sandwich panel were analyzed in detail.Further attention was paid to the effect of face-sheet thickness on the failure modes and plastic deformation of panel.The numerical results reveal that there are two evident peaks in the acceleration-time curve of the fragment and front face-sheet center,which are caused due to the impact of fragments on the front face-sheet and UHMWPE core.The front face-sheet and aluminum foam core contribute to most of the energy absorption.For the target panel with equal face-sheet thickness,a superior blast performance is achieved by well balancing between the penetration resistance of front face-sheet and the bending stiffness of back face-sheet.