Influence of weld details on fracture behavior of connections using high-strength steel. (February 2019)

• Record Type: Journal Article
• Authors: Yang, Yiting; Wang, Yan; Yang, Fan; An, Qi
• Is Part Of: Journal of constructional steel research. Volume 153(2019)
• Page Start: 578
• Page End: 587
• Publication Date: 2019-02
• Subjects: Beam-to-column connection -- Fracture toughness -- Weld details -- High strength steel -- Stress intensity factor -- J-integral; Steel, Structural -- Periodicals; Building, Iron and steel -- Periodicals; Acier de construction -- Périodiques; Construction métallique -- Périodiques; 624.1821
• DOI: 10.1016/j.jcsr.2018.11.004
• Languages: English
• ISSNs: 0143-974X

Abstract

Abstract: Based on post-earthquake research, brittle fracture of steel structures typically occurs near connection weld seams. The study proposes a new welded structure to improve the fracture resistance of connections. The fracture toughness of steel may decrease with increases in steel strength, and thus the fracture behavior of connections using high strength steel (HSS) was studied. Local welded specimens with different design details were tested under quasi-static loads, a finite element model was established, and initial cracks were assumed to analyze the fracture behavior of three types of local welded structures. Based on fracture mechanics, mode I elastic stress intensity factor ( K I ) and inelastic J-integral ( J I ) at the crack tip were calculated to predict the failure modes of HSS connections with different local welded structures. The experimental results were consistent with the expected results predicted via fracture mechanics, and the fracture of the specimen with the new design detail involving a backing strip welded at both sides occurred at a location away from the weld seam. The results indicated that the new design detail of local welded structure improves the fracture behavior of HSS connections. Highlights: A new design detail for welded structures was proposed to improve the fracture resistance of welded connections. Quasi-static tests of local welded specimens using 460 MPa high strength steel were conducted. Two failure modes were observed in the tests: fracture at the weld seam and fracture at the base metal of beam flange. Fracture behavior of the new welded structure was analyzed based on fracture mechanics. The new design detail effectively improved the fracture resistance of welded connections.