Fatigue behaviour of a welded I-section under a concentrated compression (wheel) load. (January 2018)

• Record Type: Journal Article
• Authors: Wardenier, Jaap; de Vries, Peter; Timmerman, Gerrit
• Is Part Of: Journal of constructional steel research. Volume 140(2018)
• Page Start: 163
• Page End: 173
• Publication Date: 2018-01
• Subjects: Crane runway girder -- Compression load -- Fatigue -- Fatigue cracks -- Crack growth -- Residual tensile stresses; Steel, Structural -- Periodicals; Building, Iron and steel -- Periodicals; Acier de construction -- Périodiques; Construction métallique -- Périodiques; 624.1821
• DOI: 10.1016/j.jcsr.2017.10.027
• Languages: English
• ISSNs: 0143-974X

Abstract

Abstract: This paper deals with the evaluation of fatigue cracks under a concentrated compression (wheel) load in an I-section with full penetration welds between the web and flange. The objective is to investigate whether cracks stop or nearly stop when they have grown through the residual tensile stress field. These experimental investigations are part of a review of a crane runway girder where after 20 years of service fatigue cracks were observed in the flange at the toe of the full penetration weld. The fatigue analysis of the actual crane runway girder is described in (Wardenier et al., 2017). The fatigue tests under a concentrated wheel compression loading show that, for the specimens considered on a scale of about 1:2 with stiffeners at one side, the cracks only initiate and grow at the non-stiffened side to about 50 to 60% of the web thickness and then stop. Based only on the nominal stress range under the wheel, determined according to EN 1993-6 and neglecting the shear stress effect, an equivalent fatigue class of about 160 N/mm 2 was found for crack initiation in the web, whereas the minimum ratio in life between visually observed crack initiation and maximum crack length was about a factor 3. Comparison of the codes for a wheel loading in compression shows large discrepancies in effective width and fatigue classes to be used. Highlights: The paper presents fatigue test results of a welded I beam under a concentrated compression (wheel) loading. The tests show that in these test specimens the cracks initiate only at the side grow to about 50 to 60% of the web thickness and then stop. The minimum ratio in life between visually observed crack initiation and maximum crack length was about 3. The codes for wheel loading in compression show large discrepancies in effective length and fatigue classes to be used.