Fatigue Strength Upgrading of Cover Plate Ends by Welded Extensions in Existing Steel Bridge Girders
Publication: Journal of Bridge Engineering
Volume 23, Issue 7
Abstract
This paper investigates the fatigue upgrading of typical cover plate joint connections in existing steel bridge girders through cover plate extension. The upgraded detail is created by removing the existing transverse end weld, then welding the extension to the existing cover plate with the underlying plate acting as backing. The extended cover plate should end in a zone of low stress variation. The fatigue resistance of this detail is investigated by means of scaled specimen and beam testing as well as a corroborating detailed finite-element parametric study. The different potential crack initiation sites as well as the three-dimensional effects due to the presence of longitudinal welds are considered. It is found that, depending on the exact geometry of the joint, cracks may initiate either from the weld toe or the weld root. A classification of the joint in appropriate detail categories is proposed. Depending on the thicknesses of the cover plate extension, the existing cover plate, and the underlying plate, the detail category may vary between FAT 50 (or E') and FAT 80 (or D) according to standard classifications.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This research project was financed by the Swiss Federal Railways (CFF SA). The authors wish to thank CFF SA engineers Alexandre Michon and Jean-Jacques Reber for the fruitful discussions and practical propositions made during the course of this research project as well as the experimental report drafting. They also wish to thank Martina Paronesso for her help in the final preparation of the paper. Financial support was also provided by École Polytechnique Fédérale de Lausanne (EPFL) for the completion of the finite-element studies discussed in the paper. Any opinions, findings, and conclusions or recommendations expressed in this paper are those of the authors and do not necessarily reflect the views of sponsors.
References
AASHTO. (2014). LRFD bridge design specifications, 7th Ed., Washington, DC.
ANSYS 16.2 [Computer software]. ANSYS, Canonsburg, PA.
CEN (European Committee for Standardization). (2005). “Eurocode 3: Design of steel structures–Part 1-9: Fatigue.” EN1993-1-9, Brussels, Belgium.
CEN (European Committee for Standardization). (2008). “Execution of steel structures and aluminium structures–Part2: Technical requirements for steel structures.” EN 1090-2:2008, Brussels.
El Haddad, M. H., Topper, T. H., and Smith, K. N. (1979). “Prediction of non propagating cracks.” Eng. Fract. Mech., 11(3), 573–584.
Gurney, T. R. (1979). Fatigue of welded structures, 2nd Ed., Cambridge University Press, Cambridge, U.K.
Hobbacher, A. (2016). “Recommendations for fatigue design of welded joints and components.” IIW-2259-15, 2nd Ed., Springer, Berlin.
ISO. (2014). “Welding-Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded)—Quality levels for imperfections.” ISO 5817, Geneva.
Kuhlmann, U., and Kudla, K. (2015). “Ermüdungsfestigkeit von Lamellenstößen bei Vollwandträgern mit dicken Gurten: Experimentelle und numerische Untersuchungen [Fatigue resistance of lamella joints of plated steel girders with thick flanges: Experimental and numerical investigations].” Stahlbau, 84(3), 203–212 (in German).
Livieri, P., and Lazzarin, P. (2005). “Fatigue strength of steel and aluminium welded joints based on generalised stress intensity factors and local strain energy values.” Int. J. Fract., 133(3), 247–276.
Meneghetti, G., and Lazzarin, P. (2007). “Significance of the elastic peak stress evaluated by FE analyses at the point of singularity of sharp V‐notched components.” Fatigue Fract. Eng. Mater. Struct., 30(2), 95–106.
Sedlacek, G., Hobbacher, A., Nussbaumer, A., Stötzel, J., and Schäfer, D. (2014). Commentary to EC-3–EN 1993–Part 1–9—Fatigue, S. Citarelli, B. Eichler, and M. Feldmann, eds., RWTH Aachen Stahlbau Univ., Aachen, Germany.
Taylor, D., Barrett, N., and Lucano, G. (2002). “Some new methods for predicting fatigue in welded joints.” Int. J. Fatigue, 24(5), 509–518.
Information & Authors
Information
Published In
Journal of Bridge Engineering
Volume 23 • Issue 7 • July 2018
Copyright
© 2018 American Society of Civil Engineers.
History
Received: Jan 26, 2017
Accepted: Nov 10, 2017
Published online: Apr 23, 2018
Published in print: Jul 1, 2018
Discussion open until: Sep 23, 2018
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.