强激光辐照下纯铝动力学响应和层裂的数值模拟

 采用改进的损伤度函数模型，该模型将材料损伤断裂看作为一种典型的逾渗过程，根据逾渗临界准则，采用应力松弛函数来描述损伤后期微损伤之间的连通效应，考虑了损伤对材料本构的影响，对纯铝在强激光辐照下的动态力学响应和层裂破实验进行了数值模拟。通过高斯分布激光脉冲压力加载，计算分析了激光与样品相互作用。计算结果表明：损伤演化明显地改变了材料力学响应以及样品中波传播特性，计算较精确地再现了实测自由面速度随时间的变化过程。根据计算结果分析了损伤演化过程，485 μm厚样品中损伤的分布主要集中在距离样品后界面100 μm 范围内，具有明显的损伤局部化特征，最大损伤值为11.2%。

Numerical simulation of damage evolution on mechanical behavior and tensile spallation of pure aluminium under laser shock loading

By using a modified damage function model in which the dynamic failure of shocked matter was analogous to a percolation process and a stress release function which was proposed to describe the void coalescence behavior based on the percolation critical theory,the mechanical behavior and spallation of pure aluminum subjected to intense laser irradiation were studied.The laser-driven shock loading was a Gaussian pressure pulse applied at the front surface of the sample.Simulation results indicate that the mechanical response and the wave propagation strongly depend on the damage evolution,which fits the experimental observations very well,which confirms the capability of the damage function model for describing the damage evolution in ductile metals.The damage evolution and damage distribution were analyzed.For the sample with the thickness of 485 μm,the damage was mainly concentrated in the range of 100μm near the rear free surface with a maxmum value of 11.2%.