Vol.127, No.2, 2021, pp.549-574, doi:10.32604/cmes.2021.014727
OPEN ACCESS
ARTICLE
Fatigue Crack Propagation Analysis of Orthotropic Steel Bridge with Crack Tip Elastoplastic Consideration
  • Ying Wang1,*, Zheng Yan1, Zhen Wang2
1 Jiangsu Key Laboratory of Engineering Mechanics, Southeast University, Nanjing, 211189, China
2 China Railway Major Bridge Reconnaissance and Design Institute Co., Ltd., Wuhan, 430056, China
* Corresponding Author: Ying Wang. Email:
Received 24 October 2020; Accepted 08 February 2021; Issue published 19 April 2021
Abstract
Due to the complex structure and dense weld of the orthotropic steel bridge deck (OSBD), fatigue cracks are prone to occur in the typical welding details. Welding residual stress (WRS) will cause a plastic zone at the crack tip. In this paper, an elastoplastic constitutive model based on the Chaboche kinematic hardening model was introduced, and the extended finite element method (XFEM) was used to study the influence of material elastoplasticity and crack tip plastic zone on the law of fatigue crack propagation. By judging the stress state of the residual stress field at the crack tip and selecting different crack propagation rate models to investigate the crack propagation law when plastic deformation was considered, the propagation path and propagation rate of fatigue crack of the OSBD were obtained. The results show that, whether the residual stress field is considered or not, the plastic deformation at the crack tip will not cause the obvious closure of the fatigue crack at the U-rib toe during the crack propagation process, but will significantly affect the crack propagation path. When material plasticity is considered, the propagation angle of fatigue crack at the U-rib toe basically remains unchanged along the short-axis direction of the initial crack, but is going up along the long-axis direction, and the crack tip plastic zone inhibits the propagation of the crack tip on one side. Compared with linear elastic materials, the crack propagation law considering material plasticity is more consistent with that in actual bridge engineering. In terms of the propagation rate, if the residual stress field is not considered, the fatigue crack propagation rate at U-rib toe with plasticity considered is slightly higher than that without plasticity considered, because plastic deformation will affect the amplitude of energy release rate. When considering the WRS field, the fatigue crack propagation rate at U-rib toe is increased due to the combined actions of plastic deformation and stress ratio R.
Keywords
Extended finite element; fatigue crack propagation; orthotropic steel bridge deck; welding residual stress; plastic deformation
Cite This Article
Wang, Y., Yan, Z., Wang, Z. (2021). Fatigue Crack Propagation Analysis of Orthotropic Steel Bridge with Crack Tip Elastoplastic Consideration. CMES-Computer Modeling in Engineering & Sciences, 127(2), 549–574.
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