风-浪联合作用下大跨度桥梁车-桥耦合振动分析

为研究波浪对跨海桥梁风车-桥耦合振动系统的影响，针对跨海桥梁所处风大、浪高的极端环境，建立了波浪-风-列车-桥梁动力模型，将风场视为空间相关的平稳高斯过程，高速列车采用质点-弹簧-阻尼器模型模拟，精细化全桥模型通过有限元方法建立，考虑风-列车-桥梁之间的耦合作用，波浪作为外部荷载施加到该耦合体系中。以主跨532 m某海洋桥梁为例，通过自主研发的桥梁科研软件BANSYS （Bridge Analysis System），分析了波高、风速、车速对耦合模型车辆和桥梁响应的影响。结果表明：风车-桥耦合振动体系的车辆和桥梁响应受波浪影响显著，车辆和桥梁响应在与波浪荷载一致的方向增加显著，15 m·s^-1风速下，考虑波浪影响的车辆横向加速度最大值约是不考虑波浪时的1.3倍，考虑波浪影响的跨中横向位移最大值约是不考虑波浪时的22倍，而在非一致方向波浪对车-桥响应的影响较小；不同风速下，波浪对车辆横向加速度影响显著，考虑波浪影响的车辆横向加速度约是不考虑波浪时的1.2倍，而车辆竖向加速度、轮重加载率、倾覆系数等指标主要受风速的影响；波浪基频与桥梁横向位移响应谱主峰频率一致，波浪已成为影响桥梁横向位移响应的控制因素；波浪减弱了车速对车-桥响应的影响，随着波高的增加，车辆和桥梁响应对车速的变化更不敏感。

Coupled Vibration Analysis of Vehicle-bridge for Long-span Bridge Under Wind and Wave

In order to study the effect of the waves on the wind-vehicle-bridge coupling vibration system for a sea-crossing bridge, the wave-wind-vehicle-bridge dynamic model was established. The wind field was regarded as a spatially dependent Gaussian process. The high-speed trains adopt the mass-spring-damper model, and a fined full-bridge model was established by the finite element method. The wind-vehicle-bridge coupling was considered, and waves were applied to the coupling system as external loads; as an example, the Ocean Bridge with the main span of 532 m was studied. The vehicle and bridge responses were analyzed using Bridge Analysis System (BANSYS)our bridge research software, under the influence of wave height, wind speed and vehicle speed.The results show a significant impact of wave loads on the vehicle and bridge response in the wind-vehicle-bridge system; the response increases significantly in the direction consistent with the wave load. At a wind speed of 15 m·s^-1, the maximum lateral acceleration of the vehicle considering the waves is about 1.3 times than without, and the maximum lateral displacement at mid-span considering the wave is about 22 times than without. The waves thus have a lesser impact on the responses in non-uniform directions. The effect of waves on the lateral acceleration of the vehicle at different wind speeds is significant; the lateral acceleration of the vehicle considering the waves is approximately 1.2 times than without. The indicators such as the vehicle's vertical acceleration, wheel unloading rate, and overturn factors are mainly affected by the wind speed. The fundamental frequency of the wave is consistent with the peak frequency of the lateral displacement response spectrum of the bridge. Waves thus play a major role in the transverse displacement response of a bridge. Waves weaken the impact of the vehicle speed on the vehicle and bridge response. As the wave height increases, the vehicle and bridge responses become less sensitive to the vehicle's speed.