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Fatigue Design of Spot Welded Lap Joint Considered Residual Stress

잔류응력을 고려한 점용접이음재의 피로설계

Son, Il-Seon;Bae, Dong-Ho;Hong, Jeong-Gyun;Lee, Beom-No
손일선;배동호;홍정균;이범노

  • Published : 2000.03.01

Abstract

Because welding residual stress is formidable result in electric resistance spot welding process, and it detrimentally affect to fatigue crack initiation and growth at nugget edge of spot welded la p joints, it should be considered in fatigue analysis. Thus, accurate prediction of residual stress is very important. In this study, nonlinear finite element analysis on welding residual stress generated in process of the spot welding was conducted, and their results were compared with experimental data measured by X-ray diffraction method. By using their results, the maximum principal stress considered welding residual stress at nugget edge of the spot welded lap joint subjected to tension-shear load was calculated by superposition method. And, the $\Delta$P- $N_f$ relations obtained through fatigue, tests on the IB-type spot welded lap joints was systematically rearranged with the maximum principal stress considered welding residual stress. From the results, it was found th2at fatigue strength of the IB-type spot welded lap joints could be systematically and more reasonably rearranged by the maximum principal stress($\sigma$1max-res considered welding residual stress at nugget edge of the spot welding point.

Keywords

Spot Welding;IB(In-plane Bending);Type Specimen;Fatigue StrengthWelding Residual Stress;Nonlinear Finite Element Analysis-ray Diffraction Method;Maximum Principal Stress;Fatigue Limit

References

  1. Ilseon Sohn, 1989, 'A study on the fatigue design methods and expert system development for thin steel sheet spot-welded lap joint,' Ph,D thesis, Sungkyunkwan University
  2. Nied, H. A., 1984, 'The Finite Element Modeling of the Resistance Spot Welding Process,' Welding Research Supplement, pp. 123-132
  3. Goldsmith, A., 1961, 'Handbook of Thermo Physical Properties of Solid Materials,' Reversed Edition, Vol. II, The Macmillan Co, pp. 28-56
  4. RWMA, 1981, 'Residual Welding Manual,' Vol. 1, pp. 119-143
  5. Rigaku Co., 1987, 'X-선 응력측정장치 manual,' pp. 1-16
  6. Shigley, J. E. and Mischke, C. R., 1989, Mechanical Engineering Design, 5th Edition, Mcgraw-Hill, pp. 286-288
  7. Bae, D. H., 1988, 'Stress Distribution and Fatigue Strength Evaluation of a Single Elliptical Spot Welded Lap Joint under Tension-Shear Load,' Transaction of JSAE, No. 39, pp. 98-104
  8. JSAE Committee, 1987, 'The Data Book of Spot- welding Fatigue Strength,' JSAE
  9. Radaj, D., Zhaoyun, Z. and Mohrmann, W., 1990, 'Local Stress Parameter at The Weld Spot of Various Specimen,' Engineering Fracture Mechanics, Vol. 37, No. 5, pp. 993-951
  10. Huda, H., 1997, 'Electro Thermal Analysis of Electric Resistance Spot-welding Process by 3-D FEM,' Journal of Materials Processing Technology, No. 63, pp. 672-677 https://doi.org/10.1016/S0924-0136(96)02705-7
  11. Tsai, C. L. and Dickinson, D., 1989, 'Study of Nugget Formation in Resistance Spot-welding using Finite Element Method,' 1989 Material Park conference, ASM International Materials, pp. 43-53
  12. Anastassiou, M., 1990, 'Residual Stress and Micro Structure Distribution in Spot-welded Steel Sheet; Relation with Fatigue Behavior,' Material Science and Engineering, A125, pp.141-156
  13. Bae, D. H., 1981, 'The Fracture Mechanical Fatigue Strength Evaluation of IB Type Spot-Welded Lap Joint under Tension-Shear Load,' KSAE Review, Vol. 13, No. 5, pp. 42-50
  14. Radaj, D., Zhang, S., 1995, 'Geometrically Nonlinear Behavior of Spot-welded Joint in Tensile and Compressive Shear Loading,' Engineering Fracture Mechanics, Vol. 51, No. 2, pp. 281-294 https://doi.org/10.1016/0013-7944(94)00126-3
  15. Fujimoto, 1979, 'The Stress and Displacement of IB Type Spot-welded Lap Joint under Tension-Shear Load,' JSAE Review, No. 17
  16. ASTM, 1981, 'Residual Stress Effect in Fatigue,' ASTM STP 776