多点连续动态激光冲击强化残余应力场数值分析

Continuous dynamic numerical analysis of residual stress field under multi-point laser shock peening

为了提高激光冲击强化(LSP)数值模拟效率及计算精度,基于传统激光冲击仿真策略,提出了一种连续显式动态冲击仿真策略。使用显式动态分析完成多次冲击,再进行隐式静态分析得到稳定残余应力场;建立ABAQUS三维平板有限元模型,基于该策略研究了多次冲击后残余应力场的分布;Python后处理后,残余应力模拟值与测量值吻合较好。结果表明:当激光功率密度为1GW/cm^2时最大残余应力为-212.5MPa,其测量均值为-216.7MPa,误差为1.9%。激光功率密度从1GW/cm^2增加至4GW/cm^2,残余应力层深度由0.7mm增加至1mm。验证了该策略的准确性,在大幅度提高仿真效率的基础上有效地提高了模拟精度,为大型结构大面积激光冲击强化数值模拟提供了一种仿真思路。

In order to improve the efficiency and accuracy of numerical simulation of laser shock peening(LSP),a continuous explicit-dynamic impact simulation strategy was proposed based on the traditional simulation strategy.The explicit-dynamic analysis was used directly to simulate the multiple shot peening.And then the implicit-static analysis was used to obtain the stable residual stress field after being balanced.The three-dimensional finite element model of a plate was established by ABAQUS.Based on this strategy,the distribution o£residual stress field after repeated impacts was studied.After Python post-processing,the simulated values were in good agreement with the experimental measurements.It was shown that the maximum residual stress was—212.5MPa;the mean value was—216.7 MPa,and the error was 1.9%when the laser power density was 1 GW/cm2.With the increase of laser power density from 1 GW/cm^2 to 4GW/cm^2,the depth of residual stress layer increased from 0.7 mm to 1 mm.The simulation accuracy was effectively improved on the ba-sis o￡greatly improving the simulation efficiency,providing a simulation idea for large area LSP numerical simulation of large-scale structures.