Fatigue crack-propagation law of diaphragm-to-rib welded joint in steel bridge deck. (July 2022)

• Record Type: Journal Article
• Authors: Fang, Liang; Fu, Zhongqiu; Ji, Bohai; Gao, Yuqiang
• Is Part Of: Journal of constructional steel research. Volume 194(2022)
• Publication Date: 2022-07
• Subjects: Steel bridge deck -- Diaphragm-to-rib welded joint -- Fatigue crack -- Crack-growth characteristics -- Maintenance occasion; Steel, Structural -- Periodicals; Building, Iron and steel -- Periodicals; Acier de construction -- Périodiques; Construction métallique -- Périodiques; 624.1821
• DOI: 10.1016/j.jcsr.2022.107311
• Languages: English
• ISSNs: 0143-974X

Abstract

Abstract: The crack-growth characteristics at different lengths are diverse, while blind maintenance for cracks cannot achieve satisfactory arresting effect. By carrying out numerical simulation and fatigue tests of diaphragm-to-rib welded joint (DU) specimens, the crack-growth rates, morphology and stress state at the crack tip were explored. The crack-growth process was segmented and reasonable maintenance occasions for DU cracks were proposed. The result shows that the oblique DU crack is affected by in-plane shear under out-of-plane deformation of diaphragm, driving the crack to grow to the horizontal. The DU crack presents the three-stage characteristics of fast-slow-rapid growth with the approximate demarcations of 8 mm and 40 mm. It is recommended to carry out maintenance in the first two stages to avoid entering the third rapid-growth stage. Combined with the applicability of maintenance technologies, classified maintenance methods of ICR, drilling and bolt reinforcement were proposed for cracks in three stages, respectively. Graphical abstract: Unlabelled Image Highlights: Explore the reason for crack turning under out-of-plane deformation of diaphragm. Propose three-stage growth characteristic and its demarcations of diaphragm cracks. Suggest the reasonable maintenance occasion for diaphragm cracks. Provide classified maintenance methods for diaphragm cracks of different lengths.