Numerical Simulation of Fatigue Cracking of Diaphragm Notch in Orthotropic Steel Deck Model

• Published in: Materials Vol. 16; no. 2; p. 467
• Main Authors: Zeng, Yong, He, Hongwei, Qu, Yu, Sun, Xudong, Tan, Hongmei, Zhou, Jianting
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 04-01-2023; MDPI
• Subjects: Accuracy; Bridge decks; Composite materials; Crack initiation; Crack propagation; Decomposition; diaphragm; Diaphragms; Displacement; Fatigue cracking; Fatigue cracks; Fatigue failure; Fatigue tests; Finite element analysis; Finite element method; Fracture mechanics; Growth models; Horizontal orientation; Mathematical models; Metal fatigue; OSD; Partial differential equations; Plane stress; Propagation; Simulation; Steel bridges; Steel decks; Stress propagation; Technical services; the first principal stress; XFEM; OSD; diaphragm; fatigue cracking; the first principal stress; XFEM
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16020467

Orthotropic steel deck (OSD) are widely used in steel bridges because of their many advantages, but the structures and stresses of OSD are complex and sensitive to fatigue. Based on the model test, the structural fatigue analysis of OSD is carried out by using the extended finite element method (XFEM) to understand and reveal the causes of fatigue detail cracks and the generation and propagation of fatigue cracks at the welding ends of diaphragms, U-ribs, and diaphragms, which are the main structural fatigue details of the deck. The results show that: the fatigue crack at the diaphragm opening is not caused by a single factor, but the horizontal relative displacement is the root-cause of the fatigue crack; the contribution of out-of-plane displacement to the fatigue crack is more significant than that of vertical displacement or in-plane stress, which often leads to the initiation and propagation of the fatigue crack; the crack-propagation direction is perpendicular to the contour of principal stress, and the crack propagates into the plate along the high-stress area in the horizontal direction, which is in accordance with the basic theory of crack propagation. The research methods can provide technical support for the design of similar structures.