高速冲击下多胞材料细观结构中波传播规律

目的获取安全防护结构中细观多胞材料在高速冲击下的波传播规律。方法采用基于3D-Voronoi细观多胞结构数值仿真和基于最小二乘法的局部应变梯度法,研究细观多胞结构在高速冲击下的冲击波波阵面传播规律。通过细观多胞结构数值仿真提取的位移场数据,结合局部应变梯度法得到界面清晰的冲击波波阵面。结果冲击端和支撑端分别诱发右行和左行冲击波波阵面。冲击波波阵面传播过程分为3个阶段,即冲击端诱发右行冲击波阶段、支撑端诱发左行冲击波且未压缩区刚性向右运动阶段和右行冲击波压缩区域与未压缩区域一体刚性向右运动阶段。通过冲击波波速的演化规律研究,分别获取了右行和左行冲击波波阵面的拉氏位置和拉氏波速,通过严格理论推导解释了右行冲击波波阵面具有恒定减加速度的结论。最后对冲击波波阵面划分阶段的合理性进行了验证。结论基于3D-Voronoi细观多胞结构数值仿真和基于最小二乘法的局部应变梯度法可以获取界面清晰的冲击波波阵面,细观多胞结构在高速冲击下的冲击波波阵面传播规律可为安全防护结构的设计和研究提供参考依据。

Propagating Characterization of Shock Wave in the MesoscopicStructure of Cellular Materials

The paper aims to obtain the wave propagation law of mesoscopic cellular materials in the safety protection structure under high-speed impact.In this paper, using numerical simulation based on 3D-Voronoi mesoscopic structure and local strain gradient method based on least square method, the propagation law of shock wave front of mesoscopic structure under high-speed impact is studied. Through the displacement field data extracted by the numerical simulation of the mesoscopic structure, combined with the local strain gradient method based on least square method, the shock wave front with clear interface is obtained. The shock end and the support end induce right and left shock wave fronts respectively. The shock wave front propagation is divided into three stages, namely, the stage of shock wave induced by shock end to the right, the stage of shock wave induced by support end to the left and the uncompressed area moving rigidly to the right, and the stage of right shock wave compressed area and uncompressed area moving rigidly to the right. Through the study of the evolution law of shock wave velocity, the Lagrangian position and Lagrangian wave velocity of the right and left shock wave fronts are obtained respectively, and the conclusion that the right-traveling shock wave front has a constant deceleration is explained through rigorous theoretical derivation. Finally, the rationality of the division of shock wave front is verified. Numerical simulation based on 3D-Voronoi mesoscopic structure and local strain gradient method based on least square method can obtained a clear shock wave front at the interface, and the shock wave front propagation law of mesoscopic cellular material structure under high-speed impact can provide a reference basis for the safety design and research of the protection structures.