基于计算机模拟的钛合金线性摩擦焊接焊缝内部残余应力分析

Residual stress analysis of titanium alloy linear friction welding based on computer simulation

基于轮廓法测量通过线性摩擦焊接的TC17钛合金接头内部残余应力是一个能够获得接头内部应力状况的全新破坏性技术。首先将试样切成两半;然后测量由于残余应力的释放而引起的平面轮廓的位移;最后将切面的测量轮廓作为边界条件,用线弹性有限元计算垂直于切割平面的残余应力。对TC17钛合金线性摩擦焊接接头的内部应力分布进行分析。结果表明,TC17线性摩擦焊接焊缝的拉伸残余应力主要集中在距离焊缝中心12 mm的区域内;拉应力峰值处于焊缝中心,达到360 MPa(约为TC17合金屈服强度的1/3);应力在厚度方向的分布是不均匀的,并且内部的应力大于邻近的顶部和底部表面的应力。

Based on contour measurement by TC 17 titanium alloy linear friction welding joint internal residual stress is an access to joint internal stress status of new disruptive technologies. Firstly, cut the sample in half.Then measure the displacement that due to the release of residual stress caused by plane contour. Finally take the section measurement profile as boundary conditions, twisted elastic finite element calculation of cutting plane perpendicular to the residual stress. Analyze internal stress distribution of TC17 titanium alloy linear friction welding joint. The results show that the TC17 tensile residual stress is mainly focused on the distances from the center of the weld area of 12 mm. The peak value of tensile stress in the center of the weld to 360 MPa（about a third of alloy TCI7 yield strength）. The distribution of stress in the thickness direction is uneven,and the internal stress is greater than the top and bottom of the adjacent surface stress.