连续梯度多孔金属夹芯结构的抗冲击性能及失效机理研究

The study focuses on the response of cellular metal sandwich composite structures with continuous gradients. By employing the experiments, numerical simulations and theoretical analysis systematically, dynamic responses under the intensive loading (blast and impact loading) will be investigated comprehensively. The mechanisms of deformation failure and energy dissipation will be provided. Propagation laws of stress wave in continuous graded cellular metals and failure mechanism wave-induced will be analyzed, combined with the principle of equal area to establish the dynamic plastic analytical model coupling the face sheets and cores of the continuous graded cellular sandwich structures subjected to the intensive loading, and to deduce the analytical formulations of sandwich composite structures with geometrical and physical asymmetries. Feasibility analysis will be executed on the cellular metal apparatus to fulfill uniform load impact on large scale structures. Lagrangian analysis method based on the velocity fields will be extended to stress wave propagation in the continuous graded cellular cores, to build the theoretical analysis model. Overall, the study will afford theoretical and technical supports for the applications of graded cellular metal sandwich structures in the engineering.

本项目以连续梯度多孔金属复合夹芯结构为研究对象，通过系统的实验、数值模拟及理论分析，对其在爆炸、均布撞击两种典型强动载荷作用下的动力行为展开系统研究。给出其在强动载荷作用下的变形失效机制及能量耗散机理；分析应力波在连续梯度多孔金属中的传播衰减规律以及波致失效机制，结合“等面积原则”方法，建立强动载荷作用下连续梯度多孔金属夹芯结构的面板-芯层耦合塑性动力学分析模型，并给出几何非对称、物理非对称夹芯复合结构的解析表达式；研究利用泡沫金属加载阵列装置实现较大面积均布撞击加载的可行性；将基于速度场的Lagrangian分析法扩展到连续梯度芯层中应力波传播特性分析中，提出其理论分析模型。进而为梯度多孔金属夹芯复合结构的工程应用提供理论与技术支持。

本项目采用实验、理论和数值模拟相结合的方法，对连续梯度多孔材料及其 夹芯结构在高速冲击、爆炸、均布撞击等典型强动载荷作用下的动力行为展开了系统研究。给出了芯层密度梯度分布参数对结构变形失效模式的影响，并与同质量的实体铝板及均匀芯层夹芯板的抗爆性能进行了对比分析；重点研究了应力波在连续梯度多孔金属芯层中的传播衰减规律及能量耗散、分配机制；建立强动载荷作用下连续梯度多孔金属夹芯结构的面板-芯层耦合塑性动力学分析模型；将基于速度场的 Lagrangian 分析法推广到了连续梯度芯层中应力波传播特性研究中，提出了其理论分析框架。确定了压缩冲击波在多孔金属材料中的传播特性及所产生的最大峰值应力与载荷强度、作用时间、材料特性以及材料的不均匀程度的关系。为梯度多孔金属夹芯复合结构的工程应用提供了理论与技术支持。