An analysis of endurance limit-modifying factors depending on bead shape and thickness in load-carrying welded T-joints

  • Fatih GüvenEmail author
  • Hikmet Rende
Technical Paper


Welded joints are frequently used in machine construction, ships, and bridges and must function safely throughout their service life as determined for certain circumstances defined in design codes, standards, and guidelines. Although complex analysis of welded joints gives satisfactory results, factors that modify the endurance limit are common in industrial use. The endurance limit-modifying factors given in reference books are unable to generalize to all types of welded joints. Furthermore, cracks in fillet welded T-joints are likely to start from the toe of the weld bead; however, the weld throat thickness is considered in the calculation of the strength of a welded joint. In this study, we examined the stress concentrations of load-carrying welded T-joints considering bead shape and thickness via finite element analysis and verified the model experimentally. We utilized an electromechanical cylinder to carry out experiments to obtain stresses near the weld bead via strain gauges. The submodeling technique was implemented to obtain results in the regions of stress concentrations as accurately as possible. The results of finite element analysis were in good agreement with experimental results. The present study showed that the ratio of weld throat thickness to plate thickness significantly affects the stress concentration factors of load-carrying welded joints. The maximum stress decreased significantly depending on bead shape and thickness. Endurance limit-modifying factors gathered via analyses assuming the weld as a notch and considering plate thickness could be used in the fatigue strength calculations of welded joints.


Notch effect Fatigue strength Finite element analysis Submodeling Steel Welded joint 



This work was supported by the Scientific Research Projects Coordination Unit of Akdeniz University (Project No.: FBA-2017-1940).


  1. 1.
    Schmid SR, Hamrock BJ, Jacobson BO (2013) Fundamentals of machine elements, 3rd edn. CRC Press, Boca RatonGoogle Scholar
  2. 2.
    Hobbacher A (2016) Recommendations for fatigue design of welded joints and components. Springer. CrossRefGoogle Scholar
  3. 3.
    DIN 18800 (1981) Steel structures, dimensioning and design (German). Beuth Verlag, BerlinGoogle Scholar
  4. 4.
    Eurocode 3 (1984) Common uniform rules for steel structures (German). KölnGoogle Scholar
  5. 5.
    Niemann G, Winter H, Hoehn B-R (2005) Maschinenelemente band I: Konstruktion und Berechnung von Verbindungen, Lagern, Wellen, 4th edn. Springer, BerlinGoogle Scholar
  6. 6.
    Steinhilper W, Röper R (1986) Machinen-und Konstruktions-elemente, Band II. Springer, BerlinGoogle Scholar
  7. 7.
    Decker K (1992) Machinenelemente. Carl Hanser Verlag, MünschenGoogle Scholar
  8. 8.
    Radaj D (1990) Design and analysis of fatigue resistant welded structures. Woodhead Publishing. CrossRefGoogle Scholar
  9. 9.
    Zhang G, Richter B (2000) A new approach to the numerical fatigue-life prediction of spot-welded structures. Fatigue Fract Eng Mater Struct 23:499–508CrossRefGoogle Scholar
  10. 10.
    Zhang G, Eibl M, Singh S (2002) Methods of predicting the fatigue lives of laser-beam welded lap welds subjected to shear stresses. Weld Cut 2:96–103Google Scholar
  11. 11.
    Sonsino CM (2009) A Consideration of allowable equivalent stresses for fatigue design of welded joints according to the notch stress concept with the reference Radii rref = 1.00 and 0.05 mm. Weld World 53:R64–R75CrossRefGoogle Scholar
  12. 12.
    Kranz B, Sonsino CM (2010) Verification of fat values for the application of the notch stress concept with the reference Radii rref = 1.00 AND 0.05 mm. Weld World 54:64–75CrossRefGoogle Scholar
  13. 13.
    Baumgartner J, Schmidt H, Ince E et al (2015) Fatigue assessment of welded joints using stress averaging and critical distance approaches. Weld World 59:731–742CrossRefGoogle Scholar
  14. 14.
    Pedersen MM, Mouritsen OO, Hansen MR et al (2010) Re-analysis of fatigue data for welded joints using the notch stress approach. Int J Fatigue 32:1620–1626CrossRefGoogle Scholar
  15. 15.
    Fricke W (2008) Guideline for the fatigue assessment by notch stress analysis for welded structures. Int Inst Weld 13:2208–2240Google Scholar
  16. 16.
    Baumgartner J, Bruder T (2013) An efficient meshing approach for the calculation of notch stresses. Weld World 57:137–145CrossRefGoogle Scholar
  17. 17.
    Hobbacher A (1996) Fatigue design of welded joints and components. Woodhead Publishing, CambridgeCrossRefGoogle Scholar
  18. 18.
    Fricke W (2012) IIW Recommendations for the fatigue assessment of welded structures by notch stress analysis. Woodhead Publishing, CambridgeCrossRefGoogle Scholar
  19. 19.
    Madenci E, Guven I (2015) The finite element method and applications in engineering using ANSYS, 2nd edn. Springer, New YorkCrossRefGoogle Scholar

Copyright information

© The Brazilian Society of Mechanical Sciences and Engineering 2020

Authors and Affiliations

  1. 1.Department of Machinery and Metal Technology, Başkent OSB Vocational School of Technical SciencesHacettepe UniversityAnkaraTurkey
  2. 2.Department of Mechanical Engineering, Faculty of EngineeringAkdeniz UniversityAntalyaTurkey

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