The numerical simulation on laser trepanning of square-slotted hole and hole array in stainless steel sheets with and without ultrasonic assistance was reported for analyzing the stress fields on the workpieces trepanned. Based on reasonable modification and verification for the established models using corresponding experimental results, the transient and/or residual stress distribution characteristics, which were induced by single hole trepanning and hole array trepanning with and without ultrasonic assistance, were analyzed systematically and numerically using finite element method (FEM) coupled with self-developed subprograms after predicting the transient temperature fields. The influence of ultrasonic assistance on stress reduction was also discussed. It was shown that the distribution characteristics of equivalent von-Mises stress fields on the top surface of laser trepanned workpiece were different from those on its corresponding bottom surface. For laser-trepanned workpieces, the residual stress distribution characteristics predicted after sufficient cooling were different from the corresponding transient stress characteristics simulated without sufficient cooling. As a whole, the ultrasonic assistance resulted in a small change for the distribution trend of the transient/residual stress field predicted, while the influence of ultrasonic-induced softening effect on laser trepanned workpiece was primarily demonstrated by the effective reduction of the stress values.

报道了在有超声辅助和无超声辅助的情况下，不锈钢缝隙方孔和孔阵列的激光打孔的数值模拟，以分析被打孔工件上的应力场。在对已有模型进行合理修改和验证的基础上，采用相应的实验结果，对有限元和无超声辅助下的单孔开孔和孔阵列开孔引起的瞬态和/或残余应力分布特征进行了有限元分析和数值模拟。预测瞬态温度场后，该方法（FEM）与自行开发的子程序结合使用。还讨论了超声辅助对减轻应力的影响。结果表明，激光刻蚀工件上表面的等效von-Mises应力场分布特征与其对应的下表面上的等效应力场分布特征不同。对于激光打磨的工件，充分冷却后预测的残余应力分布特征与没有充分冷却时模拟的相应瞬态应力特征不同。总体而言，超声辅助使所预测的瞬态/残余应力场的分布趋势发生了很小的变化，而超声诱导的软化效果对激光精轧工件的影响主要通过有效降低应力值来证明。对于激光打磨的工件，充分冷却后预测的残余应力分布特征与没有充分冷却时模拟的相应瞬态应力特征不同。总体而言，超声辅助使所预测的瞬态/残余应力场的分布趋势发生了很小的变化，而超声诱导的软化效果对激光精轧工件的影响主要通过有效降低应力值来证明。对于激光打磨的工件，充分冷却后预测的残余应力分布特征与没有充分冷却时模拟的相应瞬态应力特征不同。总体而言，超声辅助使所预测的瞬态/残余应力场的分布趋势发生了很小的变化，而超声诱导的软化效果对激光精轧工件的影响主要通过有效降低应力值来证明。