不同波长激光冲击强化力学效应数学模型构建

Construction of mathematical models for mechanical effects oflaser shock strengthening with different wavelengths

为实现更好的强化效果,克服强化后表面形貌不够均匀等问题,设计不同波长激光冲击强化的力学效应数学模型。使用Johnson-Cook模型构建金属构件的材料本构模型,对基础材料模型加载激光冲击波压力,以激光冲击强化原理为依据,构建不同波长下的构件激光冲击强化有限元模型。基于构建的有限元模型,探究材料的动态屈服强度与构件材料的雨贡纽弹性极限之间的关系,构建应变与冲击波峰值压力之间的理论模型,根据该模型表示激光冲击强化产生的残余压应力,完成不同波长激光冲击强化力学效应数学模型的构建。测试结果表明,基于该模型强化后,实验构件表面形貌整体比较均匀,凹坑深度较小,过光斑中心直线上构件材料表面位移变化区间在[-0.4,0.5]之间,说明设计模型性能较好,具有实用性。

To achieve better strengthening effects and overcome issues such as uneven surface morphology after strengthening,a mathematical model for mechanical effects of laser shock strengthening with different wavelengths is designed.Using the Johnson Cook model to construct a material constitutive model of metal components,the basic material model is loaded with laser shock wave pressure,and based on the principle of laser shock strengthening,a finite element model of component laser shock strengthening at different wavelengths is constructed.Based on the constructed finite element model,this study explores the relationship between the dynamic yield strength of materials and the Hugoniu elastic limit of component materials,constructs a theoretical model between strain and peak pressure of shock waves,and represents the residual compressive stress generated by laser shock strengthening according to this model.The construction of a mathematical model for the mechanical effects of laser shock strengthening at different wavelengths is completed.The test results show that after strengthening based on this model,the surface morphology of the experimental components is generally uniform,with small pit depths.The displacement range of the component material surface on the straight line passing through the center of the light spot is between[-0.4,0.5],indicating that the design model has good performance and practicality.