轻质梯度多孔金属夹芯结构的弹道冲击破坏机理研究

Metal sandwich structure with a graded cellular core is a new lightweight multifunctional structure with extensive potential applications in protective structures and it is significant and helpful to investigate the ballistic impact failures. Based on experiments, this project will systematically investigate the ballistic penetration and perforation failures of the metal sandwich structures with a graded cellular core. Firstly, the ballistic experiments for the sandwich structures are systematically performed by employing high velocity gas gun to study the ballistic impact mechanism. Secondly, the microstructure models for the graded cellular cores and the sandwich structures are then developed, respectively. The ballistic penetration and perforation processes of the graded cellular cores and the sandwich structures impacted by the high velocity projectiles are simulated by using finite element method. The ballistic impact mechanisms of the graded cellular cores and the sandwich structures are then revealed.Effects of the cell configurations, sizes, strain rates, projectile configurations and density gradient on the ballistic impact failures are analyzed. The influences of the structural components on ballistic limit velocity and residual velocity, and energy absorption ability are studied further. Finally, the analytical models for the ballistic limit velocity and residual velocity of the sandwich structures impacted by the high velocity projectiles are proposed.

梯度多孔金属夹芯结构是一类有广泛应用潜力的新型轻质防护结构，研究其弹道冲击破坏机理有重要理论意义和实用价值。本项目拟以实验为基础，研究梯度多孔金属夹芯结构的弹道冲击破坏机理。首先，利用高速气炮高速加载装置，实验研究梯度多孔金属夹芯结构的弹道行为。其次，建立梯度多孔金属及其夹芯结构的精细结构模型，借助有限元方法模拟弹道侵彻与贯穿过程，揭示梯度多孔金属及其夹芯结构在弹道冲击过程中的破坏机理，分析芯材孔构型、尺寸、应变率、弹体形状、密度梯度分布等因素，对夹芯结构弹道冲击破坏的影响，进而研究各结构组分对夹芯结构弹道极限速度和击穿后弹体剩余速度的影响以及各自的吸能表现。最后，建立梯度多孔金属夹芯结构计算弹道极限速度和击穿后弹体剩余速度的分析模型。

梯度多孔金属夹芯结构是一类有广泛应用潜力的新型轻质防护结构，研究其弹道冲击破坏机理有重要理论意义和实用价值。本项目以实验为基础，研究了密度梯度多孔金属泡沫铝夹芯结构的弹道冲击破坏机理。实验通过高速气炮加载，获得了高速冲击下不同密度梯度多孔金属夹芯结构的失效模式，建立了梯度多孔金属及其夹芯结构的精细结构模型，借助有限元方法模拟弹道侵彻与贯穿过程，揭示梯度多孔金属及其夹芯结构在弹道冲击过程中的破坏机理。. 研究了爆炸载荷下几何非对称蜂窝铝夹芯结构的动力响应及吸能机理，发展了其大挠度动力响应的理论分析模型，理论预测与实验结果吻合得很好，结果表明，面板非对称性对夹芯结构的变形和失效模式有重要的影响。进一步发展了爆炸载荷下金属泡沫夹芯梁结构大挠度动力响应的简化分析模型和爆炸载荷下金属泡沫夹芯板大挠度动力响应分析模型，理论预测与有限元计算结果吻合得很好。. 研究了密度梯度分布金属泡沫的抗冲击响应，提出了一个冲击波在密度梯度泡沫金属中传播的理论分析模型，理论预测与有限元计算结果吻合的很好，该研究结果对梯度泡沫设计提供了重要理论依据。