FATIGUE DAMAGE PARAMETER OF SPOT WELDED JOINTS UNDER PROPORTIONAL LOADING

  • KANG H. T. (Department of Mechanical Engineering, University of Michigan)
  • 발행 : 2005.06.01

초록

In this paper, the author proposes a fatigue damage parameter of spot welded joints under proportional loading. The proposed fatigue damage parameter is developed based on von Mises' equivalent stress and local structural stress at the edge of spot weld nugget. The structural stress at the edges of the weld nugget in each sheet is calculated using the forces and moments that are determined by finite element analysis. A structural equivalent stress is then calculated by von Mises' equivalent stress equation. The structural equivalent stresses are correlated to experimental fatigue life of the spot welded joints. The proposed parameter is evaluated with fatigue test data of spot welds subjected to multi axial and tensile-shear loads. Sheppard's parameter and Rupp and co-workers' parameter are also evaluated with the same test data to compare with the author's parameter. This proposed parameter presents a better correlation with experimental fatigue data than those of Sheppard's and Rupp and co-workers' parameter. The proposed parameter should be very effective for durability calculations during the early design phase since coarsely meshed finite element models can be employed.

키워드

참고문헌

  1. Barkey, M. E., Kang, R. and Lee, Y. (2001). Failure modes of single resistance spot welded joints subjected to combined fatigue loading. International Journal of Materials and Product Technology 16, 617, 510-526 https://doi.org/10.1504/IJMPT.2001.001278
  2. Reyes, P. and Fermer M. (1996). A spot-welded fatigue analysis module in the MSC/FATIGUE environment SIAT'96, India, Dec. 5-7
  3. Kan, Y. (1976). Fatigue resistance of spotwelds - An analytical study. Metals Engineering Quarterly, November, 26-36
  4. Kang, H. and Barkey, M. E. (1999). Fatigue life estimation of resistance spot-welded joints using an interpolation/extrapolation technique. International Journal of Fatigue 21,8,769-777 https://doi.org/10.1016/S0142-1123(99)00043-2
  5. Kang, H. (1999). Fatigue Analysis of Spot Welds Subjected to Combined Tension and Shear Loading, Ph.D Dissertaition, The University of Alabama
  6. Radaj, D. and Zhang, S. (1991a). Stress intensity factors for spot welds between plates of unequal thickness. Engineering Fracture Mechanics 39, 2, 391-413 https://doi.org/10.1016/0013-7944(91)90053-4
  7. Radaj, D. and Zhang, S. (1991b). Simplified formulae for stress intensity factors of spot welds. Engineering Fracture Mechanics 40, 1,233-236 https://doi.org/10.1016/0013-7944(91)90142-N
  8. Radaj, D. and Zhang, S. (1992). Stress intensity factors for spot welds between plates of dissimilar materials. Engineering Fracture Mechanics 42, 3, 407-426 https://doi.org/10.1016/0013-7944(92)90163-9
  9. Rupp, A., Storzel, K. and Grubisic, V. (1995) Computer aided dimensioning of spot welded automotive structures. SAE Paper No. 950711, Detroit, Michigan
  10. Sheppard, S. D. (1993). Estimation of fatigue propagation life in resistance spot welds. Advances in Fatigue Predictive Techniques: Second Volume, ASTM STP 1211, Philadelphia, 169-185
  11. Sheppard, S. D. (1996). Further refinement of a methodology for fatigue life estimation in resistance spot weld connections. Advances in Fatigue Predictive Techniques: 3rd Volume, ASTM STP 1292, Philadelphia, 265-282
  12. Swellam, M. H., Kurath, P. and Lawrence, F. V. (1991). electric-potential-drop studies of fatigue crack development in tensile shear spot welds. ASTM STP 1122, ASTM, Philadelphia, PA, 383-401
  13. Swellam, M. H. and Lawrence, F. V. (1991). A fatigue design parameter for spot welds. Fracture Control Program Report No. 157 (Also Ph.D Dissertation of MH. Swellam), University of Illinois at Urbana-Champaign
  14. Young, W. C. (1989). Roark's Formulas for Stress & Strain Sixth Edition. McGraw-Hill Inc., New York