斜拉桥主梁损伤对车激索力响应的影响研究

Research on the Influence of Girder Damage of Cable-stayed Bridge to Cable Force Responses Under the Action of Moving Vehicle Load

以斜拉桥的损伤识别为目的,提出了一种索力比指标,研究了斜拉桥在车辆荷载激励下,主梁发生损伤时斜拉索索力比指标的变化规律。以实验室独塔斜拉桥试验模型为研究对象,基于ANSYS建立其空间板壳有限元模型,以单元刚度的折减模拟主梁损伤,对主梁在不同位置损伤、不同程度损伤两类工况下,车辆荷载激励下斜拉索的索力比指标变化进行了数值仿真。结果表明:车辆荷载激励下,斜拉索的索力比指标与主梁的损伤位置和损伤程度存在一定的对应关系。为后续基于车辆荷载激励下的索力响应指标识别斜拉桥损伤方法的研究提供了重要的参考,具有一定的理论意义。

In order to detect the damage of the cable-stayed bridge, the cable force ratio index is presented in this paper. The cable force ratio indexes are studied while the main girder of cable-stayed bridge is damaged under the action of moving vehicle load. Taking a single-tower cable-stayed bridge test model as research object, a space plate shell finite element model is established by ANSYS. The damage of main girder is simulated by the stiffness reduction. Numerical simulation is done to research the change of cable force ratio index when the girder has different damage locations and different damage extent under vehicle excitation. It is shown that the cable force ratio index is closely connection with damage location and extent of girder when the vehicle load across the bridge. The research presented in this paper provides some theoretical reference for damage detection based on cable force response index under vehicle load excitation.