基于激光冲击波三维无损打标的数值模拟

Numerical simulation of 3-D nondestructive marking based on laser shock wave

为了研究激光冲击波打标后标记区域的残余应力分布与材料变形情况,基于ANSYS/LS-DYNA建立了激光冲击波打标的三维有限元模型,通过激光诱导的冲击波加载,进行了打标的数值模拟。模拟结果表明,激光冲击波作用后的标记区域网格形成了与载荷直径相仿的凹坑,其残余应力均表现为压应力,并随着形变量的逐渐增加,在标记中心残余压应力达到最大值;材料厚度方向的残余压应力随着材料厚度的增加而不断减小,在1mm^1.4mm深度范围内载荷的作用效果不明显。这一结果可用于指导激光冲击波三维无损打标残余应力场的理论分析及其实验研究。

In order to study the distribution of residual stress and distortion, a FEM model of marking by means of laser shock waves was established based on ANSYS/LS-DYNA. By loading the shock waves induced by laser, a numerical simulation of marking was carried out. The simulated results showed that the mesh of marking area acted by laser shock waves formed a crater with dimension similar to the diameter of the load, and its residual stress was compressive stress. As the amount of the deformation increased gradually, the residual compressive stress in the center of marking area reached the maximum ; the residual compressive stress along the thickness of the material declined as the thickness increased, and the loading effect was not obvious in the depth of 1mm - 1.4mm. The results are applicable in theoretical analysis and experimental research of residual stress field of 3-D nondestructive marking based on laser shock wave.