A Current Problem for Steel Bridges: Fatigue Assessment of Seams´ Repair

Authors: H. Pasternak, A. Chwastek

Abstract:

The paper describes the results from a research project about repair of welds. The repair was carried out by grinding the flawed seams and re-welding them. The main task was to determine the FAT classes of original state and after repair of seams according to the assessment procedures, such as nominal, structural and effective notch stress approach. The first part shows the results of the tests, the second part encloses numerical analysis and evaluation of results to determine the fatigue strength classes according to three assessment procedures.

Keywords: Cyclic loading, fatigue crack, post-weld treatment, seams’ repair.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1126840

References:

[1] T. Nitschke-Pagel, H. Pasternak, G. Lener et al., “Bemessungskonzepte für Trag- und Dauerfestigkeitsberechnungen von Reparaturschweißungen - Repair Welding of Structures”, Research Project IGF-No. 54EBG, 2015.
[2] H. Pasternak, A. Chwastek, “Zur Entwicklung eines Bemessungskonzeptes für die Lebensdauer von Reparaturschweißungen”, Bauingenieur Vol. 90(2015) pp. 47-54 and pp. 272-277.
[3] A. Hobbacher, “Recommendations for fatigue design of welded joints and components”, Doc. IIW XIII-1539-96/XV845-96, Paris, October 2008.
[4] C. Morgenstern et al., “Fatigue design of aluminium welded joints by the local stress concept with fictitious notch radius of rt = 1mm”, International Journal of Fatigue Vol. 28(2006), pp.881-890.
[5] A. Chwastek, “A contribution to the development of fatigue assessments of newly repaired fillet welds based on small specimens" (in German), Dissertation, BTU, Cottbus. Germany 2016, to be published.
[6] DIN EN1993-1-9:2010, Eurocode 3: Bemessung und Konstruktion von Stahlbauten - Teil 1-9: Ermüdung, Dezember 2010.