多胞金属材料在中速压溃下的波传播规律及本构行为研究

Cellular material, which is widely used in anti-impact field, will inevitably experience the impact environment of moderate-velocity crushing during the application. But the previous work has been mainly focused on the low-velocity and high-velocity mechanical behavior of cellular materials. Thus, it is urgent to understand the mechanical behavior of cellular materials under the specific impact scenario of moderate-velocity crushing. A cell-based finite element simulation method is mainly applied to carry out numerical experiments of cellular metallic materials under moderate-velocity crushing in this project, which is intended to observe the deformation characteristics and wave propagation phenomena, reveal the law of wave propagation, develop characterization methods of wave propagation scale information and investigate the influence of meso-scale parameters on the characteristic information of wave propagation. Considering the multi-scale characteristics of cellular materials, a theoretical wave propagation model in account of scale effect will be proposed to research the variations of physical quantities such as stress and strain, which is based on the understanding of the characteristic scale information of wave propagation. The dynamic stress-strain constitutive behavior will be investigated based on the above research under moderate-velocity impact. The mesoscopic deformation mechanism and corresponding relation with macroscopic mechanical behavior will be revealed. The expected results may provide sufficient understandings of dynamic mechanical behavior of cellular metallic materials under moderate-velocity impact, which is contributed to provide theoretical guidance for impact resist and anti-blast design. This research will also provide thoughts and methods for other porous structural materials.

冲击防护领域被广泛使用的多胞材料在应用过程中不可避免地会经历中等速度压溃的冲击环境，但现有工作主要集中于对其低速和高速压溃情形下的力学行为的研究。因此迫切需要认识多胞材料在中速压溃的特定冲击情形下的力学行为。本项目拟主要采用细观有限元模拟的方法对多胞金属进行中等速度压溃的动态数值实验，观察变形特征及波传播现象，揭示波传播规律，发展波传播特征尺度信息的表征方法，研究细观参数的变化对波传播特征信息的影响规律；考虑到多胞材料的多尺度特征，基于波传播特征信息建立计及尺度影响的波传播理论模型，研究应力、应变等物理量的变化规律；基于上述研究，考察多胞金属材料的动态应力-应变本构行为，揭示中速压溃下的细观变形机理及其与宏观力学行为的关联。通过该课题的研究，预期获得对多胞金属在中等速度压溃下动态力学行为的认识，为冲击防护及抗爆设计提供理论指导，也为其他多孔结构材料的研究提供思路和方法。

本项目主要针对冲击防护领域被广泛使用的蜂窝铝及泡沫铝等多胞材料在中速压溃下的动态力学性能展开研究，基于细观有限元模拟得到了多胞材料的变形模式及波传播规律，发展了波传播特征信息表征方法；基于改进SHPB装置开展了直接撞击实验，获得了中速压溃下特征参量的变化规律；建立了计及尺度影响的塑性波传播理论模型，得到了应力、应变等物理参量的变化关系，拓展了多胞材料在动态压溃下的动态应力-应变行为。基于本项目研究，加深了对多胞金属动态压溃力学行为的认识，可为特定工程应用背景下的冲击防护及抗爆设计提供理论指导，也可为其他非均质材料/结构的应用研究提供思路和方法。