FEM analysis study on fatigue strength and fracture morphology in spot welded joints of structural steels

被引：1
作者：
Tohgo, Keiichiro [1 ]
Ohguma, Tomoya [2 ]
Shimamura, Yoshinobu [1 ]
Ojima, Yoshifumi [3 ]
机构：
[1] Dept of Mech. Eng., Shizuoka Univ., Naka-ku, Hamamatsu
[2] Graduate School, Shizuoka Univ., Naka-ku, Hamamatsu
[3] Material Eng. Dept, Mitsubishi Motors Corp., Okazaki, 444-501, Hashime-cho
来源：
Zairyo/Journal of the Society of Materials Science, Japan | 2009年 / 58卷 / 07期
关键词：
Fatigue strength; Finite element method; Fracture mechanics; Fracture morphology; Spot welded joints; Threshold of fatigue crack growth; Ultra-high strength steels;
D O I：
10.2472/jsms.58.627
中图分类号：
学科分类号：
摘要：
In this paper, fatigue tests and finite element method (FEM) analyses are carried out on spot welded joints of mild steel (270MPa class) and ultra-high strength steel (980MPa class) in order to investigate the influence of strength level of base steels on fatigue strength and fracture morphology of spot welded joints. From the fatigue tests the following results are obtained : (1) The fatigue limit of spot welded joints is almost the same in both steels. (2) Three-dimensional morphology of crack initiation and growth around a nugget is made clear. (3) The fatigue fracture morphology of spot welded joints depends on the load level in the ultra-high strength steel, but not in the mild steel. From the discussion based on the FEM analyses the following results are obtained: (4) The fatigue limit of spot welded joints can be predicted by stress intensity factors around a nugget, fracture criterion from a mixed mode crack and threshold values for fatigue crack growth in base steels. (5) The plastic deformation around a nugget in spot welded joints strongly affects the fatigue fracture morphology. © 2009 The Society of Materials Science, Japan.
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页码：627 / 634
页数：7
相关论文
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