Research on Fatigue Strength for Weld Structure Details of Deck with U-rib and Diaphragm in Orthotropic Steel Bridge Deck

Abstract

The orthotropic steel bridge deck weld structure would easily cause fatigue cracking under the repeated action of vehicle load. This paper took the steel box girder in a bridge as a research object, researched the mechanical properties of the steel plate and the microstructure of the welded joint, then designed the fatigue specimens of the deck plate and did the fatigue test. The Δσ-N curves and stress amplitudes of the weld details of the deck plate with U-rib and diaphragm under different probabilities of survival were obtained. After extended the Δσ-N curves to the long life range, the fatigue damage calculation equation of the detail was proposed, and the cut-off limit under the 50% and 97.7% probability of survival were 81.50 MPa and 53.11 MPa, respectively. Based on the actual vehicle load spectrum and simplified finite element model of the steel box girder section, the stress amplitude of the details of the weld joint was calculated. The calculation result shows that the maximum stress amplitude of the concerned point was 38.29 MPa, less than the cut-off limit. It means that the fatigue strength of the details of the weld joint meet the requirement of the fatigue design.

Fracture, Fatigue, and Structural Integrity of Metallic Materials

“…Thus, in the fatigue context, Yao et al [1] analyze the fatigue behavior of aluminum foam sandwich panels fabricated through liquid diffusion welding and adhesive methods, also providing microstructural and metallurgical analyses; Chen et al [2] investigate the fatigue behavior of a given steel bridge deck by characterizing (experimentally) the fatigue performance of the deck plates and the deck welded details, and performing stress analysis. Hardy and DuQuesnay [3] characterize the fatigue performance of hi-lok fasteners used in aircraft structural joints and subjected to multiple collar replacements, as well as the corresponding behavior under static loading conditions.…”

Modeling of fatigue failure mode in U‐rib to deck joints in orthotropic bridge structures

“…The local stress concept, including the notch structural stress method with various fictitious notch radii, is investigated and considered by Karakas et al 19–22 Besides, the notch stress method has been extended for evaluating fatigue performances of welded structures in multiaxial stress states by Tao, 23 Luca, 24 and Ran 25 . The recommended evaluation methods on the fatigue properties of OBD are associated with some limitations 15,26–29 . Pei and Dong 30 further extended this method to a low‐cycle fatigue regime and came up with a structural strain method, which can correlate both high‐ and low‐cycle fatigue data weldments made from different base metals into a master E‐N curve.…”

Study of Secondary Effects of Fatigue Cracks in Cross Partitions of Steel Plate Reinforced Steel Box Girders

“…However, the fatigue of the parent material of the curved cutout of the cross-sectional plate is still the main fatigue disease of the steel box girder [4][5][6][7]. Although a lot of research has been conducted on the optimization of the reinforcement of steel box girder cross-sectional cutouts [8,9]. However, under the wheel load, the effect of the optimized reinforcement of the cross-sectional slit on the stress distribution in the critical parts of the steel box girder (curved slit, cross-sectional slit, U-rib, deck slab, etc.)…”