波纹膜片中空激光冲击成形仿真研究

Simulation research on hollow laser shock forming of corrugated diaphragm

为了改善波纹膜片实心激光冲击成形时膜片的中心部位容易产生反向塑性变形,甚至发生破裂的问题,采用数值模拟的方法探索了波纹膜片中空激光冲击成形,通过分析膜片成形后的截面轮廓以及厚度分布研究了中空激光光斑对波形膜片成形性能的影响。研究结果表明:在进行波纹膜片中空激光冲击成形时合适的光斑内径可以有效地减小膜片中心区域的反向塑性变形,使膜片和凹模底部贴合更紧密;并且合适的光斑内径可以有效地改善波纹膜片冲击成形后的厚度分布,避免膜片中心部位厚度严重减薄造成的破裂失效。

In solid laser shock forming of corrugated diaphragm,there are several problems in central part of the dia- phragm, such as producing reverse plastic deformation and even occurring fracture. To solve those problems, numerical simulation is applied to explore hollow laser shock forming of the diaphragm. Effect of hollow laser spot on diaphragm formability is researched through analyzing section contour and thickness distribution of the diaphragm after shock forming. The result shows that when conducting hollow laser shock forming of corrugated diaphragm, reverse plastic deformation in central part of the diaphragm can be effectively reduced by adopting appropriate inner diameter of hollow laser, which makes the diaphragm fit die more tightly. Thickness distribution of the diaphragm after shock forming can also be improved with appropriate inner diameter,which avoids facture in central part of the diaphragm as a result of severe thinning.