冲击作用下多孔材料热力学特征的模拟与分析

Simulation study of shock wave reaction on porous material

强冲击波的作用可在多孔材料中诱发复杂的时空耗散过程,在这期间系统整体处于远离平衡的状态,对这一过程的稳定模拟和结果分析均具有较强的挑战性。使用近期针对超高速碰撞而发展起来的物质点方法对这一过程进行模拟,引入积分几何和数值图像处理中的形态学描述来处理和分析系统热力学特征量例如温度的Turing斑图,揭示出3个Minkowski泛函(白色区域相对面积、边界总长度、欧拉特征量)与系统中"高温区"所占份额、"热点"在空间的分布方式之间的对应,揭示出Minkowski泛函演化特征与冲击波及多孔材料相互作用过程之间的对应。研究了孔隙度和冲击波强度对物质状态参量的影响。

Complex spatial-temporal dissipative structures occur in shocked porous material. The system is globally in nonequilibrium. Both the simulation and data analysis for such a system are challenging. The system was simulated by using the material-point method which was developed recently. The Minkowski functionals were introduced to describe the Turing pattern of the map of state variable like temperature. The relevance among the three Minkowski functionals, the area fraction of the high-temperature regions and the distribution of ＂hot-spots＂ in space was pointed out. The shock wave reaction with inhomogeneous material was studied by analyzing the evolution of Minkowski functionals. The effects of porosity and shock-wave-strength were investigated.