激光喷丸诱导的残余应力的有限元分析

激光喷丸成形是一项新技术,是利用强激光辐照材料表面产生的高压冲击波对材料内部诱导的残余应力来成形金属板料的,控制残余应力场的分布是精确成形板料的关键。有限元模拟技术是预测激光诱导的残余应力场的有效方法之一。该文建立激光诱导残余应力模拟的模型,讨论了模拟过程中关键问题的技术处理,如加载历史、本构关系、网格划分、求解时间等。数值模拟的过程主要包括动态分析和静态分析两个步骤,模拟结果表明,残余压应力的大小和残余压应力层的深度随激光的功率密度的增加而增加,最后趋于饱和。模拟结果和试验结果较为一致。

Finite element simulation of residual stress induced by laser peening

Laser peen forming is a production process used to create curved metal parts from sheet,which employs the residual stress induced by laser to form metallic sheet.Finite element analysis is an effective method to predict the field of residual stress in the material treated by laser shot peening.The elastic-plastic constitutive model of material acted by stress wave is discussed.A finite element modeling was established and an analysis procedure including dynamic analysis and static analysis is presented in detail to predict the residual stress field.History of the energies during dynamic analysis is analyzed and validated by the theoretical calculation.The magnitude of compressive residual stresses and the affected depth can be increased and gradually reach the saturated state with the increase of laser power density.The predicted residual stress field for single laser shot peening is well correlated with the available experimental data.