考虑残余应力的激光搭接焊接头拉伸和疲劳试样宽度标准化

Standardized width of tensile and fatigue specimens of laser lap welded joints considering residual stress

摘要: 抗剪强度和疲劳强度是激光搭接焊接头性能的两个最重要指标。关于激光搭接焊接头的拉伸和疲劳试样的宽度选取，目前还没有相应的标准进行规定。以不锈钢薄板激光搭接焊接头为研究对象，通过残余应力数值与试样宽度变化关系的测定，确定了考虑和不考虑残余应力影响的拉伸和疲劳试样合理宽度，比较了有无残余应力试样抗剪强度的区别。结果表明，残余应力通过改变焊接接头受力状态和微观变形均匀性降低了薄板激光搭接焊接试样的抗剪强度。

Abstract: The shear strength and fatigue strength are important mechanical properties of the laser lap welded joints. However, no standard has regulated the dimensions of the tensile and fatigue specimens. In this paper, the reasonable widths of the laser lap welded specimens were determined by taking account of the residual stress. The shear strengths of specimens with residual stress and without residual stress were studied. It was found that the residual stress reduced the shear strength of the laser lap welded joints by change the stress state and micro-deformation uniformity.