Static and Fatigue Strength of Laser Welded Lap Joints.
Static and Fatigue Strength of Laser Welded Lap Joints.
复制标题
激光焊接搭接接头的静态强度和疲劳强度。
DOI：
10.2207/qjjws.14.586
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Masanori Ohmura
中科院分区：
文献类型：
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作者：
M. Ono;M. Kabasawa;Masanori Ohmura
激光焊接具有焊接速度快、热变形小的优点。因此，激光焊接对于连接薄钢板是非常有吸引力的工艺。本文研究了激光焊接搭接接头的静强度和疲劳强度，搭接接头的抗拉强度由母材强度和焊缝强度中较弱的一个决定。母材的强度用抗拉强度和厚度估算，焊缝的强度用焊缝的硬度和宽度估算。因此，不同母材抗拉强度和厚度的接头强度计算值与试验值吻合较好。疲劳裂纹萌生于焊缝边缘，沿着熔合线向自由面扩展。采用断裂力学方法对不同厚度搭接接头的疲劳强度进行了评估。采用J.Chang和R.采用Erdogan准则和Sih准则对疲劳强度进行评价。结果表明，该方法不仅适用于点焊搭接接头的疲劳强度评估，而且适用于激光焊接搭接接头的疲劳强度评估。
Laser welding has the advantage of high welding speed and provides low heat distortion. Thus, laser welding is very attractive process for joining thin steel sheets. In this study, static and fatigue strength of laser welded lap joints were investigated.Tensile strength of the lap joints was determined by the weaker one between the strength of base metal and that of weld metal. The strength of the base metal was estimated with the tensile strength and thickness, and the strength of the weld metal was estimated with the hardness and width of the weld metal. Thus, the calculated strength coincided with the experimental strength of the joint with different tensile strength and thickness of the base metal.Fatigue crack initiated at the edge of weld metal, and propagated along the fusion line to the free surface. We employed fracture mechanics to evaluate the fatigue strength of the lap joint with different thickness. Stress intensity factor of the lap joint was calculated with the analysis of J. Chang and R. Muki.We employed criterion of Erdogan and Sih to evaluate the fatigue strength. By this criterion, the fatigue strength was well characterized.As a result, this approach, which was originally developed to evaluate fatigue strength of spot welded lap joints, was also effective for fatigue strength of laser welded lap joints.