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Spot Weld Fatigue Life Prediction of Auto Set Belt Anchors Using $K_e$

K_e에 의한 차량 안전벨트 앵커의 점용접 피로수명 예측

Kim, Nam-Ho;Lee, Hyeong-Il
김남호;이형일

  • Published : 2000.03.01

Abstract

As the welding spot forms a singular geometry of an external crack type, fatigue failure of spot-welded specimens can be evaluated by means of a fracture parameter. Recasting the load vs. fatigue life relationships experimentally obtained, we predicted the fatigue life of spot-weld specimens with a single parameter denoted the equivalent stress intensity factor. This crack driving parameter is demonstrated to successfully describe the effects of specimen geometry and loading type in a comprehensive manner. The suggested fatigue life formula for a single spot weld can play a key role in the design and assessment of spot-welded panel structures, in that the fatigue strength of multi-spots is eventually determined by the fatigue strength of each single spot. We therefore attempt to evaluate the effectiveness and validity of $K_e$ in predicting the fatigue life of auto seat belt anchor panel. We first establish finite element models reflecting the actual mechanical behavior of 3 types of seat belt anchor specimens. Using finite element models elaborately established, we then obtain the effective crack driving parameter $K_e$ composed of its ductility -dependent modal components. It is confirmed that the $K_e$ concept successfully predicts the fatigue life of multi-spot welded panel structures represented by auto seat belt anchors here

Keywords

Spot Welding;Multi-spot Welding;fatigue Failure;Fatigue Life;Panel Structure;Equivalent Stress Intensity Factor;Auto Seat Belt Anchor

References

  1. Broek, D., 1986, Elementary Engineering Fracture Mechanics, 4th Edition, Martinus Nijhoff Publishers, Chapter 14
  2. ABAQUS Version 5.5 User's Manual, 1995, Hibbitt, Karlsson and Sorensen, Inc., Pawtucket, RI
  3. Wang, P. C. and Ewing, K. W., 1988, 'A J- integral Approach to Fatigue Resistance of a Tensile-Shear Spot Weld,' SAE Paper 880373
  4. Wang, P. C. and Ewing, K. W., 1991, 'Fracture Mechanics Analysis of Fatigue Resistance of Spot Welded Coach-Peel Joints,' Fatigue and Fracture of Engineering Materials and Structures, Vol. 14, No. 9, pp. 915-930 https://doi.org/10.1111/j.1460-2695.1991.tb00725.x
  5. 이형일, 김남호, 이태수, 2000, '점용접시편의 극한하중과 피로특성에 관한 실험적 고찰,' 대한기계학회논문집, 제24권, 제1호, pp. 38-51
  6. Tada, H., Paris, P. C. and Irwin, G. R., 1985, The Stress Analysis of Cracks Handbook, 2nd Edition, Paris Production, Inc., St. Louis
  7. 이태수, 이형일, 신수정, 1998, '점 용접점 파단의 정량적 모델-1 파단조건식,' 한국자동차 공학회 논문집, 제6권, 제6호, pp. 40-52
  8. 신수정, 이형일, 이태수, 최양욱, 1999, '점 용접점 파단의 정량적 모델-2 판형구조해석,' 한국자동차 공학회 논문집, 제7권, 제l호, pp. 161-172
  9. Pook, L. P., 1975, 'Fracture Mechanics Analysis of the Fatigue Behavior of Spot Welds,' International Journal of Fracture, Vol. 11, pp. 173-176 https://doi.org/10.1007/BF00034726
  10. 이형일, 최진용, 1998, '점용접시편의 과부하 해석 및 유효 J-적분에 의한 피로수명예측,' 대한기계학회 논문집 제24권, 3호, pp. 567-580