大件运输车作用下宽幅斜拉桥动力响应分析

Dynamic response analysis of wide cable-stayed bridge under customized transportation vehicle

为研究大件运输车辆作用下桥梁的动力响应,建立了以实际工程为背景的宽幅斜拉桥有限元模型和精细化的车辆有限元模型,并利用LS-DYNA程序的接触算法实现了相较于传统方法更为真实的车-桥耦合振动模拟,以车辆类型、行驶车道、行驶速度等为参数,对比不同工况下桥梁的振动响应。结果表明:在大件运输车辆通过宽幅斜拉桥时,相较于标准车辆会引起桥梁更大的竖向下挠和拉索索力;边车道工况下桥梁的竖向位移变幅和索力变幅大于中间车道工况下的变幅;大件运输车辆行驶速度的提升会使桥梁竖向下挠和拉索索力增加,且相较于中间车道工况,边车道工况下桥梁响应对车速的敏感度更高。

An finite element model of wide cable-stayed bridge and refined finite element model of vehicle are established for the purpose of studying the dynamic responses under customized transportation vehicle(CTV),based on a practical engineering background.Compared with traditional methods,a more realistic simulation for vehicle-bridge coupled vibration is realized by using the contact algorithm within LS-DYNA.According to the parameters of vehicle type,lane and speed,the obtained conclusion from contrastive analysis of bridge's vibration response in different working conditions are as follows.When CTV passes wide cable-stayed bridge,it brings greater vertical deflection and cable force to bridge compared with standard vehicles.Amplitude of bridge's vertical displacement and cable force in side lane working condition is larger than that in middle lane working condition.The increase of CTV's passing speed brings greater vertical displacement and cable force,and the sensitivity of bridge dynamic responses to vehicle speed is higher in side lane working condition compared with the middle lane working condition.