The vehicle-bridge interaction influence on suspender of arch bridge under various driving parameters

The fatigue durability of suspenders is the key problem in the operation and maintenance stage of the bridge. Based on the research background of a long-span tied arch bridge in China, the theoretical model of vehicle-bridge- interaction (VBI) is established. The numerical model of the bridge was established to carry out VBI analysis. Then, the influence of road roughness, speed, transverse lane and vehicle type are analyzed, the parameters that should be considered during the analysis of VIB were determined. Finally, the random traffic simulation program was adopted to simulate the traffic parameters to calculate the stress spectrum of suspenders under different driving parameters. In addition, the rain flow count method was utilized to count the fatigue stress amplitude and its cyclic number. By combination S–N curve with Palmgren-Miner cumulative damage criterion, the fatigue life of uncorroded suspenders and corroded suspenders was estimated. The results show that the fatigue life of suspenders considering corrosion or not are 100 years and 20 years, respectively and the difference of driving parameters of vehicles should be fully considered during the analysis.