Numerical simulation of root-deck crack propagation of orthotropic steel bridge deck

Abstract

The fatigue crack at the rib-to-deck joint that initiated at the weld root and propagated through the deck plate is one of the most common and unfavorable crack types on orthotropic steel deck (OSD). To evaluate the fatigue performance of OSD during its life-cycle in a more accurate way, a numerical simulation method to reproducing the behavior of this type of crack was established based on linear elastic fracture mechanics (LEFM) in this paper. Firstly, the crack growth at the weld root was provided by the fatigue test using the beach marking method. Then, by adopting the proposed crack propagation simulation method, the crack growth in the test was simulated and the fatigue cracks growth life was predicted. Finally, some factors that may have a great influence on crack propagation behaviors were analyzed, including the lack of penetration defects (LOP) at the weld root, the angle between the crack surface and the deck plate, initial crack depth as well as crack aspect ratio. Accordingly, a practical approach was put forward to estimate the fatigue life based on the test, which can be applied to actual structures that are manufactured by the same process of the specimens, and the inspection and maintnenance works can be benefitted.