车桥耦合作用下系杆拱桥吊杆疲劳耐久性分析

Fatigue Durability Analysis for Suspenders of a Tied Arch Bridge Under Vehicle-bridge-interaction

针对车桥耦合作用下拱桥吊杆的疲劳耐久性能,以国内某大跨系杆拱桥为依托,建立了系杆拱桥车桥耦合振动的理论分析模型,并对比了桥面不平整度、车速、横向车道和车辆类型等车辆运行参数的影响。采用随机车流模拟程序模拟车辆运行参数,获取不同桥面不平整情况下吊杆的应力谱,运用雨流计数法计算疲劳应力幅与循环次数,结合S-N曲线与Palmgren-Miner疲劳累积损伤准则,对是否考虑腐蚀因素的吊杆疲劳寿命进行了估算。结果表明:不考虑腐蚀作用时,吊杆的疲劳寿命可达100年以上,而考虑腐蚀的影响时,吊杆的疲劳寿命为20年左右,车桥耦合分析需充分计入不同车辆运行参数的差异。

By taking a large-span tied arch bridge as study object,the fatigue durability of arch bridge suspenders under the action of vehicle-bridge-interaction(VBI)are studied.The theoretical analysis model of VBI and numerical model the bridge are established to carry out VBI analysis.In addition,the influences of vehicle operation parameters such as road roughness,speed,transverse lane and vehicle type are compared.Then,the random traffic simulation program was adopted to simulate the vehicle running parameters to calculate the stress response of suspenders under different road roughness.Finally,the rain flow count method was utilized to count the fatigue stress amplitude and cyclic number.By combination SN 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 and20 years respectively and the difference of running parameters of vehicles should be fully considered during the analysis.