Grinding treatment effect on rib-to-roof weld fatigue performance of steel bridge decks

Fu, Zhuojia; Ji, Bohai; Kong, Xiangming; Chen, Xiang

doi:10.1016/j.jcsr.2016.09.018

Cited by 36 publications

(11 citation statements)

References 9 publications

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“…Fatigue cracks usually initiate in correspondence of stress localizations caused by geometric discontinuities and notches [ 7 ]. Therefore, it is important to assess the stress concentration of welded joints for both accurate prediction of their fatigue life and to propose a geometrical shape of the weld (for example, by grinding [ 8 ]) that could improve the fatigue performance.…”

Section: Introductionmentioning

confidence: 99%

Parametric Formula for Stress Concentration Factor of Fillet Weld Joints with Spline Bead Profile

2020

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The existing parametric formulae to calculate the notch stress concentration factor of fillet welds often result in reduced accuracy due to an oversimplification of the real weld geometry. The present work proposes a parametric formula for the evaluation of the notch SCF based on the spline weld model that offers a better approximation of the real shape of the fillet weld. The spline model was adopted in FE analyses on T-shape joints and cruciform joints models, under different loading conditions, to propose a parametric formula for the calculation of the SCF by regression analysis. In addition, the precision of parametric formulae based on the line model was examined. The magnitude of the stress concentration was also analyzed by means of its probability distribution. The results show that the line model is not accurate enough to calculate the SCF of fillet weld if the weld profile is considered. The error of the SCF by the proposed parametric formulae is proven to be smaller than 5% according to the testing data system. The stress concentration of cruciform joints under tensile stress represents the worst case scenario if assessed by the confidence interval of 95% survival probability.

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Section: Introductionmentioning

confidence: 99%

Parametric Formula for Stress Concentration Factor of Fillet Weld Joints with Spline Bead Profile

2020

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“…These parameters for two grinding types are shown in Table 8. The grinding radius r and depth of grinding type 1 (GT1) are 3 mm and 0.5 mm, respectively, and the grinding arc intersects with the deck [34]. The grinding type 2 (GT2) is a new grinding type proposed in the present study.…”

Section: Influence Of Grinding Typesmentioning

confidence: 87%

“…The grinding treatment effectively increases the transitional radius of the welds and reduces the stress concentration without changing the local microstructure, which improves the fatigue life of deck-rib welding details. Furthermore, the influence of the grinding radius and depth of the local stress field at the weld toe have been studied [33,34]. In the present study, a new grinding type is proposed, and the influence of the grinding radius on the fatigue life is discussed based on the stress integration approach.…”

Section: Appl Sci 2019 9 X For Peer Review 2 Of 25mentioning

confidence: 95%

Influence of Weld Parameters on the Fatigue Life of Deck-Rib Welding Details in Orthotropic Steel Decks Based on the Improved Stress Integration Approach

et al. 2019

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Fatigue cracks in orthotropic steel decks (OSDs) have been a serious problem of steel bridges for a long time. The structural stress approach is an important approach for fatigue life evaluation of welded structures. Firstly, two parameters and the mesh sensitivity of the stress-based integration equivalent structural stress approach (stress integration approach for short) are analyzed in this paper. Then, the applicability of the master S-N curve is verified based on experimental data of the deck-rib welding details in OSDs. Finally, the multi-scale finite element model (FEM) of Jiangyin Bridge is established, and the bridge fatigue life calculation steps based on the stress integration approach are given. The influence of the slope of the master S-N curve at high cycles on the bridge fatigue life is discussed. Further, the weld parameter influences on the bridge fatigue life are analyzed, as including the following: (1) The determination of the influence of the weld size changes caused by weld manufacturing errors on the bridge fatigue life; (2) the proposal of a new grinding treatment type, and the analysis of influence of the grinding radius on fatigue life; and (3) a comparison of the fatigue life of the deck-rib welding details under 80% partial penetration and 100% full penetration. The results show that the structural stress calculated by the stress integration approach does not change significantly with the parameters of the isolation body width w and the distance δ between the crack propagation surface and the reference surface. To simplify the calculation, δ is set as 0, and w can be set as the mesh size along the weld length direction. The mesh size of the stress integration approach is recommended as 0.25 times the deck thickness. The slope of the master S-N curve at high cycles significantly affects the bridge fatigue life, and a slope of 5 is reasonable. The weld parameter studies for the deck-rib welding details in the OSD of Jiangyin Bridge show that the change of weld size caused by manufacturing errors can obviously affect the bridge fatigue life, and the fatigue life of five different weld types varies from 51 years to 113 years. The new grinding treatment type, without weakening the deck, is beneficial to improving the bridge fatigue life. The fatigue life increases by approximately 5% with an increase of the grinding radius of 2 mm. The fatigue life of 80% partial penetration is slightly higher than that of 100% full penetration.

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“…Considering the cracking characteristics in real bridges, 7 gages were set along the transverse of the deck, which were 10mm from the welding end to measure the nominal stress. The distance 10mm was determined by the stress gradients of the welding end to ensure the nominal stress was not affected by the geometric discontinuity [18]. In the vicinity of the welding end, the space between the gages was comparatively smaller, namely 35mm.…”

Section: Stop-hole and Cfrp Reinforcement(sj6)mentioning

confidence: 99%

Fatigue Repairing Craftsmanship of Deck-to-Vertical Stiffener Weld in the Steel Bridge Deck

2019

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Experiments and FE analysis were conducted on the fatigue repairing techniques of deck-to-vertical stiffener weld in the steel bridge deck. The steel bridge deck was modeled to analyze cracking reason of deck-to-vertical stiffener weld. The fatigue repairing experiment was carried out on three repairing techniques. The fatigue life and stress distribution of the deck-to-vertical stiffener weld were analyzed and repairing effects were compared. Repairing craftsmanship with different parameters was modeled to study change of stress distribution. Besides, influence of welding residual stress, stop-hole and CFRP reinforcement on fatigue repairing was discussed. The results showed that cracks of welding end on the deck were induced by out of plane deformation while those on the vertical stiffener were caused by combined out-of-plane and inplane deformation, which was more prone to cracking. Residual tensile stress reached yield strength of steel after rewelding, thus hammering and polishing after re-welding could improve fatigue life of the weld. The re-welding techniques had more favorable repairing effects than stop-hole and CFRP reinforcement.

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Grinding treatment effect on rib-to-roof weld fatigue performance of steel bridge decks

Cited by 36 publications

References 9 publications

Parametric Formula for Stress Concentration Factor of Fillet Weld Joints with Spline Bead Profile

Parametric Formula for Stress Concentration Factor of Fillet Weld Joints with Spline Bead Profile

Influence of Weld Parameters on the Fatigue Life of Deck-Rib Welding Details in Orthotropic Steel Decks Based on the Improved Stress Integration Approach

Fatigue Repairing Craftsmanship of Deck-to-Vertical Stiffener Weld in the Steel Bridge Deck

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