Fatigue Behavior of Hangers on a Three Tower Suspension Bridge

Oujiang Beikou Bridge under design is a three tower suspension bridge with a main span of 217.405+2x800+275=2092.405m. Fatigue analysis of the hangers on the bridge is a necessity in the design to ensure safety and functionality. In this paper, fatigue life assessment of the hangers is proposed considering both the load effect and the hanger resistance. The load effect is calculated through the random traffic model based on the Monte Carlo simulation and the finite element model established by ANSYS. Random vehicle load and spacing are both simulated in the model and the traffic volume is predicted. The resistance is calculated according to the Eurocode and the corrosion effect is also taken into consideration using the S-N curves for the corroded steel wires. It is noted in the paper that the influence lines of hangers have a wide range and the load effect can be shared by 80 hangers. The fatigue life of hangers on three tower suspension bridge is much longer than the lifetime when the corrosion effect is not considered and the corrosion has a big impact on the fatigue life. The length of hangers is associated with the fatigue damage and the hangers at the two ends of the three tower suspension bridge on the side span suffer the largest fatigue damage.