激光冲击Johnson-Cook模型材料参数优化

Johnson-Cook model of material parameter optimization for laser shock processing

采用Abaqus有限元软件,建立激光冲击718镍铬合金诱发的残余应力场非线性弹塑性有限元模型,实现激光冲击强化残余应力场的数值仿真.通过仿真分析及试验结果对照,说明以Johnson-Cook模型作为本构关系是可行的,激光冲击能形成残余压应力层,提高疲劳寿命,但由于应变率的差异,必须对JC模型材料参数进行优化,才能取得较精确的结果,并从激光功率密度对残余应力场的分析进一步加以验证.结果表明,提出的JC模型材料参数优化方法简单易行.

The finite element software Abaqus was applied to establish a nonlinear elastic-plastic finite element model for predicting the residual stress distribution induced by laser shock processing（LSP） of Inconel 718.It was shown by comparison between simulation and experimental data that the Johnson-Cook constitutive model was feasible to form a layer of compressive residual stress on the Inconel 718 target surface and improve fatigue life after LSP.However,due to the differences in the strain rate,the JC model material parameters should be optimized in order to obtain more accurate result and that was further verified by using laser power density in the residual stress field analysis.The result showed that this JC model was simple and feasible whose material parameters could be optimized.