Skip to main content
Log in

Weld Root Magnification Factors for Semi-Elliptical Cracks in T-Butt Joints

  • Published:
Acta Mechanica Solida Sinica Aims and scope Submit manuscript

Abstract

Many researchers have focused their efforts on fatigue failures occurring on weld toes. In recent years, more and more fatigue failures occur on weld roots. Therefore, it is important to explore the behaviour of weld root fatigues. This paper investigates numerically the Magnification factors (Mk) for types of semi-elliptical cracks on the weld root of a T-butt joint. The geometry of the joint is determined by four important parameters: crack depth ratio, crack shape ratio, weld leg ratio and weld angle. A singular element approach is used to generate the corresponding finite element meshes. For each set of given four parameters of the semi-elliptical root crack, the corresponding T-butt joint is numerically simulated and its Mk at the deepest point of the weld root crack is obtained for the respective tension and shear loads. The variation range of the four parameters covers 750 cases for each load, totaling 1500 simulations are completed. The numerical results obtained are then represented by the curve to explore the effects of four parameters on the Mk. To obtain an approximate equation representing Mk as a function of the four parameters for each load, a multiple regression method is adopted and the related regression analysis is performed. The error distributions of the two approximate equations are compared with the finite element data. It is confirmed that the obtained approximate functions fit very well to the database from which they are derived. Therefore, these two equations present a valuable reference for engineering applications in T-butt joint designs.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Balasubramanian, V. and Guha, B., Analyzing the influences of weld size on fatigue life prediction of FCAW cruciform joints by strain energy concept. Int. J. Pressure Vessel Piping, 1999, 76: 759–768.

    Article  Google Scholar 

  2. Lu, Y.L., A practical procedure for evaluating SIFs along fronts of semi-elliptical surface cracks at weld toes in complex stress fields. Int. J. Fatigue, 1996, 18: 127–135.

    Article  Google Scholar 

  3. Lie, S.T., Zhao, Z. and Yan, S.H., Two-dimensional and three-dimensional magnification factors, Mk, for non-load-carrying fillet welds cruciform joints. Eng. Fract. Mech., 2000, 65: 435–453.

    Article  Google Scholar 

  4. Kirkhope, K.J., Bell, R., Caron, L., Basu, R.I. and Ma, K.T., Weld detail fatigue life improvement techniques. Mar. Struct., 1999, 12: 447–474.

    Article  Google Scholar 

  5. Fricke, W., Review fatigue analysis of welded joints: state of development. Mar. Struct., 2003, 16: 185–200.

    Article  Google Scholar 

  6. Poutiainen, I. and Marquis, G., A fatigue assessment method based on weld stress. Int. J. Fatigue, 2006, 28: 1037–1046.

    Article  Google Scholar 

  7. Khodadad Motarjenmi, A., Kokabi, A.H., Ziaie A.A., Manteghi, S. and Burdekin, F.M., Comparison of the stress intensity factor of T and cruciform welded joints with different main and attachment plate thickness. Eng. Fract. Mech., 2000, 65: 55–66.

    Article  Google Scholar 

  8. Choi, D.H., Choi, H.Y. and Lee, D., Fatigue life prediction of in-plane gusset welded joints using strain energy density factor approach. Theor Appl Fract Mech, 2006, 45: 108–116.

    Article  Google Scholar 

  9. Al, Mukhtar, A.M., Henkel, S., Biermann, H. and Hubner, P., A finite element calculation of stress intensity factor of cruciform and butt welded joints for some geometrical parameters. Jordan Journal of Mechanical and Industrial Engineering, 2009, 3: 236–245.

    Google Scholar 

  10. Dijkstra, O.D., Snijder, H.H. and van Straalen, I.J., Fatigue crack growth calculations using stress intensity factors for weld toe geometries. In: Proc. Eighth Int Conf Offshore Mech Arctic Engng, The Hague, 1989: 137–143.

  11. Thurlbeck, S.D., A Fracture Mechanics Based Methodology for the Assessment of Weld Toe Cracks in Tubular Offshore Joints. PhD thesis, UMIST, 1991.

  12. Hou, C.Y., Fatigue analysis of welded joints with the aid of real three-dimensional weld toe geometry. Int J Fatigue, 2007, 29: 772–785.

    Article  Google Scholar 

  13. Pommier, S., Sakae, C. and Murakami, Y. An empirical stress intensity factor set of Equations for a semi-elliptical crack in a semi-infinite body subjected to a polynomial stress distribution. Int J Fatigue, 1999, 21: 243–251.

    Article  Google Scholar 

  14. Balasubramanian, V. and Guha, B., Effect of weld size on fatigue crack growth behaviour of cruciform joints by strain energy density factor approach. Theor Appl Fract Mech, 1999, 31: 141–148.

    Article  Google Scholar 

  15. Brennan, F.P., Dover, W.D., Kare, R.F. and Hellier, A.K., Parametric equations for T-butt weld toe stress intensity factors. Int J Fatigue, 1999, 21: 1051–1062.

    Article  Google Scholar 

  16. Maddox, S.J., An analysis of fatigue cracks in fillet welded joints. Int J Fract, 1975, 11(2): 221–243.

    Article  Google Scholar 

  17. Newman, J.C. and Raju, I.S., An empirical stress intensity factor equation for the surface crack. Eng. Fract. Mech., 1981, 15: 185–192.

    Article  Google Scholar 

  18. Bowness, D. and Lee, M.M.K., Weld toe magnification factors semi-elliptical cracks in T-butt joints comparison with existing solutions. Int. J. Fatigue, 2000, 22: 389–396.

    Article  Google Scholar 

  19. Bowness, D. and Lee, M.M.K., Prediction of weld toe magnification factors for semi-elliptical cracks in T-butt joints. Int. J. Fatigue, 2000, 22: 369–387.

    Article  Google Scholar 

  20. Fu, B., Haswell, J.V. and Bettess, P., Weld magnification factors for semi-elliptical surface cracks in fillet welded T-butt joint models. Int. J. Fract., 1993, 63: 155–171.

    Article  Google Scholar 

  21. BS 7910: Guide to Methods for Assessing the Acceptability of Flaws in Metallic Structures, BSI 2005.

  22. Gilles, P. and Franco, C., A new J-estimation scheme for cracks in mismatching welds—the ARAMIS method. In: Mismatching of Welds, Eds by Schwalbe, M. and Kocak, K.H., London: Mechanical Engineering Publications, 1994: 661–683.

    Google Scholar 

  23. Eripret, C. and Hornet, P., Prediction of overmatching effects on the fracture of stainless steel cracked welds. In: Mismatching of weld, Eds by Schwalbe, K.H. and Kocak, M., London: Mechanical Engineering Publications, 1994: 685–708.

    Google Scholar 

  24. Wang, Y.Y. and Kirk, M.T., Geometry effects on failure assessment diagrams. In: Proceedings of Second International Symposium on Mismatching of welds, Reinstorf-Luneburg, Germany, 1996.

  25. Francis, M. and Rahman, S., Probabilistic analysis of weld cracks in center-cracked tension specimens. Computers and Structures, 2000, 76: 483–506.

    Article  Google Scholar 

  26. Ganta, B.R. and Ayres, D.J., Analysis of Cracked Pipe Weldments, EPRI Report No. NP–5057, Electric Power Research Institute, Palo Alto, February, 1987.

  27. Rahman, S. and Brust, F., An estimation method for evaluating energy release rates of circumferential through-wall cracked pipe welds. Eng. Fract. Mech., 1992, 43: 417–430.

    Article  Google Scholar 

  28. O’Donoghue, P.E., Atluri, S.N. and Pipkins, D.S., Computational strategies for fatigue crack growth in three dimensions with application to aircraft components. Eng. Fract. Mech., 1995, 52: 51–64.

    Article  Google Scholar 

  29. Gurney, T.R., An analysis of some fatigue crack propagation data for steels, subjected to pulsating tension loading. Weld Res. Int., 1979, 9: 45–52.

    Google Scholar 

  30. Fricke, W. and Kahl, A., Numerical and experimental investigation of weld root fatigue in fillet-welded structures. International Shipbuilding Progress, 2008, 55: 29–45.

    Google Scholar 

  31. Zhou, C.Z., Yang, X.Q. and Luan, G.H., Effect of root flaws on the fatigue property of friction stir welds in 2024-T3 aluminum alloys. Mater. Sci. Eng. A, 2006, 418: 155–160.

    Article  Google Scholar 

  32. Kanvinde, A.M., Gomez, I.R., Roberts, M., Fell, B.V. and Grondin, G.Y., Strength and ductility of fillet welds with transverse root notch. Journal of Constructional Steel Research, 2009, 65: 948–958.

    Article  Google Scholar 

  33. Chung, H.Y., Liu, S.H., Lin, R.S. and Ju, S.H., Assessment of stress intensity factors for load-carrying fillet welded cruciform joints using a digital camera. Int. J. Fatigue, 2008, 30: 1861–1872.

    Article  Google Scholar 

  34. Kim, I.T., Weld root crack propagation under mixed mode and cyclic loading. Eng. Fract. Mech., 2005, 72: 523–534.

    Article  Google Scholar 

  35. Bowness, D. and Lee, M.M.K., Weld toe magnification factors for semi-elliptical cracks in T-butt joints. OTO Report 99014, Health and Safety Executive, 1999.

  36. Henshell, R.D. and Shaw, K.G., Crack tip finite elements are unnecessary. Int. J. Numer. Meth. Engng., 1975, 9: 495–507.

    Article  Google Scholar 

  37. Barsoum, R.S., On the use of isoparametric finite elements in linear fracture mechanics. Int. J. Numer. Meth. Engng., 1976, 10: 25–37.

    Article  Google Scholar 

  38. ABAQUS User’s Manual, Version 6.3, Hibbitt, Karlsson and Sorensen, Inc. 2002.

  39. Fung, Y.C., A First Course in Continuum Mechanics, 2nd ed., Prentice-Hall, 1977.

  40. Cohen, J., Applied multiple regression/correlation analysis for the behavioral sciences, 3rd ed., Mahwah, NJ: L Erlbaum Associates, 2003.

    Google Scholar 

  41. Curve Fitting Toolbox, Functions, Data fitting for MATLAB, notes for R2009b. The Math Works Inc, 2009.

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Yeping Xiong.

Additional information

Project supported by the National Basic Research Program (973 Program) of China (No. 2011CB711102). The authors would like to acknowledge Professor M.M.K. Lee for providing information and deep discussions.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Song, Z., Xiong, Y., Xie, J. et al. Weld Root Magnification Factors for Semi-Elliptical Cracks in T-Butt Joints. Acta Mech. Solida Sin. 26, 317–330 (2013). https://doi.org/10.1016/S0894-9166(13)60029-4

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1016/S0894-9166(13)60029-4

Key Words

Navigation