Yu Yin, Wang Wenqiang, He Hongliang, Lu Tiecheng
National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP, 621900, Mianyang, People's Republic of China and Department of Physics and Key Laboratory for Radiation Physics and Technology of Ministry of Education, Sichuan University, 610064, Chengdu, People's Republic of China.
National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP, 621900, Mianyang, People's Republic of China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Apr;89(4):043309. doi: 10.1103/PhysRevE.89.043309. Epub 2014 Apr 28.
The influence of the evolution of numerous voids on macroscopic properties of materials is a multiscale problem that challenges computational research. A shock-wave compression model for brittle material, which can obtain both microscopic evolution and macroscopic shock properties, was developed using discrete element methods (lattice model). Using a model interaction-parameter-mapping procedure, qualitative features, as well as trends in the calculated shock-wave profiles, are shown to agree with experimental results. The shock wave splits into an elastic wave and a deformation wave in porous brittle materials, indicating significant shock plasticity. Void collapses in the deformation wave were the natural reason for volume shrinkage and deformation. However, media slippage and rotation deformations indicated by complex vortex patterns composed of relative velocity vectors were also confirmed as an important source of shock plasticity. With increasing pressure, the contribution from slippage deformation to the final plastic strain increased. Porosity was found to determine the amplitude of the elastic wave; porosity and shock stress together determine propagation speed of the deformation wave, as well as stress and strain on the final equilibrium state. Thus, shock behaviors of porous brittle material can be systematically designed for specific applications.
大量孔隙演化对材料宏观性能的影响是一个具有挑战性的多尺度计算研究问题。利用离散元方法（晶格模型）建立了一种脆性材料的冲击波压缩模型，该模型能够同时获得微观演化和宏观冲击性能。通过模型相互作用参数映射程序，计算得到的冲击波剖面的定性特征和趋势与实验结果相符。在多孔脆性材料中，冲击波分裂为弹性波和变形波，表明存在显著的冲击塑性。变形波中的孔隙坍塌是体积收缩和变形的自然原因。然而，由相对速度矢量组成的复杂涡旋模式所表明的介质滑动和旋转变形也被确认为冲击塑性的一个重要来源。随着压力的增加，滑动变形对最终塑性应变的贡献增加。发现孔隙率决定弹性波的振幅；孔隙率和冲击应力共同决定变形波的传播速度以及最终平衡状态下的应力和应变。因此，可以针对特定应用系统地设计多孔脆性材料的冲击行为。
