几何形状对激光冲击波诱发残余应力场的影响

摘要

为了提高钛合金类杆件的疲劳强度,采用Nd:Glass强脉冲激光对TCA漏斗形试件的表面进行了激光冲击处理,用X射线应力仪测试了冲击区域的残余应力,同时利用有限元软件ANSYS对不同形状的试件即平面试件、漏斗形试件和圆柱形试件以及不同的试件直径与光斑直径比η的激光冲击处理过程进行了模拟.结果表明,模拟与试验取得较好的一致性,且漏斗形试件可简化为与之相应的圆柱形试件进行模拟;试件形状对残余应力场的影响主要体现在Y方向和Z方向,而对X方向的残余应力分布几乎没有影响;不同的η主要影响光斑中心处深度方向即径向和周向的残余应力分布,而对轴向影响较小.%In order to improve the fatigue strength of TC4, Nd:Glass pulse laser was used to treat the surface of infundibulate specimen X-ray stress analyzer was adopted to test the residual stress distribution of shocked area, and the process of laser shock on different geometrical specimen with different ratio (η)between the diameter of specimen and laser spot were simulated by ANSYS. The results show that the simulation is in good agreement with experiments. The infundibnlate specimen can be simplified to cylindrical specimen. Geometrical effects on residual stress mainly act on X direction and Z direction and almost no effects on Y direction. The different η's mainly affect residual stress distribution along the indepth direction and the circumferential direction, but very few on longitudinal direction.