大跨度简支钢桁梁桥车-桥耦合振动影响因素分析

以黄韩侯铁路新黄河特大桥156m简支钢桁梁桥作为工程背景,建立车辆动力模型、桥梁有限元模型并考虑轮轨关系,以蛇形运动和轨道不平顺作为系统的自激激励源,利用大型有限元软件ANSYS以及UM(Universal Mechanism)动力学分析软件联合进行仿真分析。从桥梁结构的桥门架、宽跨比、曲线钢桁梁桥和车辆系统的轨道不平顺以及货车编组角度出发,研究大跨度简支钢桁梁桥车-桥耦合振动的影响因素。经过计算分析得出:钢桁梁桥桥门架对桥梁跨中加速度影响较大;曲线钢桁梁桥随着线路半径的增大,各车辆动力响应参数逐渐变小,轮轨力受到影响;钢桁梁桥宽跨比的增加使得横向刚度随之增加,桥梁横向振动变小;各项车辆动力响应均随着轨道情况变差而总体呈现逐渐增大趋势,车辆安全性、舒适性和平稳性指标逐渐变差;全列空车编组和空重混编对钢桁梁车-桥耦合系统是不利的编组形式,实际情况中应该避免。

Analysis of the Influencing Factors of Train-bridge Coupled Vibration of a Large-span Simply-supported Steel Truss Railway Bridge

With the rapid development of rail transportation in China, high-speed and heavy-load railways have become the trend of development in this field. In such systems, it is important to consider the interaction process between the train and the bridge, along with the influential factors, when a train passes through a bridge. In this paper, a 156-m long simply-supported steel truss bridge of the Huang Han-hou New Yellow River Railway is taken as an example. A dynamic model of the train-bridge was constructed considering a wheel-rail relationship. Serpentine movements and track irregularity were used as self-excited excitation sources of the train-bridge system. The finite element software ANSYS and UM (Universal Mechanism) were used to simulate the train-bridge coupled vibrations. The influence of the bridge structure of the portal frame, wide-span ratio, curve of the steel truss and track irregularity, as well as the marshaling coaches on the train-bridge coupled vibrations were discussed with the numerical simulations. The results showed that the gantry of the steel truss bridge had greater influence on the acceleration. As the line radius of the curved steel truss bridge increased, the dynamic responses of the train became smaller, thus affecting wheel-rail force. Moreover, with increasing wide-span ratio, the lateral stiffness of the bridge increases, and the bridge lateral vibration became smaller. When the track conditions became worse, the dynamic responses of the train increased considerably and the comfortable and stability worsened. The findings indicate that the full empty grouping and empty-weight mixed grouping schemes are harmful to the coupled system of a train-bridge, which should be avoided in practical operation.