ANALYSIS OF The DYNAMIC STRESS RESPONSE OF THE HANGERS IN ARCH BRIDGE UNDER SPEED-VARYING VEHICLE

The hangers of arch bridge are important bearing components and also the components which are easily destroyed. The main reason of hanger failure is the fatigue damage under the alternating stress caused by the dynamic coupling of vehicles and bridge structure. The vehicle-bridge coupling simulation is conducted for a large-scale concrete-filled steel tube arch bridge by considering the road roughness, 3-D characteristics and speed-varying of the vehicle. The axial forces, bending moment and nouniformity of the alternating stress over hanger sections are discussed. The results show that the acceleration of the vehicle will significantly increase the vehicle impact on the bridge, and the bending moment in hanger section is obviously influenced by vehicle speed, acceleration, and road roughness, while the lateral bending moment is usually larger than the longitudinal bending moment. The dynamic stress over the hanger section shows significant nonuniformity, with the maximum value being about twice the minimum, while the percentage of the bending stress is about 30% of the total stress. These factors should be considered in design, maintenance, monitoring and evaluation for this kind of bridge.