多点连续动态激光冲击强化残余应力场数值分析

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1 GW/cm2时最大残余应力为-212.5 MPa,其测量均值为-216.7 MPa,误差为1.9%。激光功率密度从1 GW/cm2增加至4 GW/cm2,残余应力层深度由0.7 mm增加至1 mm。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。 

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

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 of 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 -212.5 MPa; 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/cm2 to 4 GW/cm2, the depth of residual stress layer increased from 0.7 mm to 1 mm. The simulation accuracy was effectively improved on the basis of greatly improving the simulation efficiency, providing a simulation idea for large area LSP numerical simulation of large-scale structures.