Abstract: In order to study the interaction between vehicle and straddle type monorail beam, a simply-supported PC track beam of straddle type monorail line in Chongqing was taken as the research object to establish the coupled vibration model. Each car in the monorail train was idealized as a dynamic system of 15-degrees-of-freedom. The cornering characteristics of the tires were taken into consideration. Vehicle’s differential equations were derived by using Lagrange formulation. The track beam was idealized as Euler beam and its differential equations were derived by using modal synthesis method. The dynamic responses of the coupled system were studied at different running velocities, which were compared with the field-test data and the results of the model which has no cornering characteristics. The results show that a proper correlation is found and the model which considers cornering characteristics gives a more actual result. The cornering characteristics can be ignored when studying the vertical coupled vibration problem and should be taken into consideration when studying the lateral problem.

Key words: bridge engineering, straddle type monorail, coupled vibration system of vehicle and beam, cornering characteristic

摘要： 为研究跨座式单轨交通车辆-轨道梁系统的耦合振动，以重庆市跨座式单轨交通-预应力混凝土简支梁为研究对象，建立了车辆和轨道梁的耦合振动模型。每节车辆简化为15个自由度的动力系统，并考虑所有轮胎的侧偏特性。车辆运动微分方程由拉格朗日方程导出，轨道梁简化为欧拉梁，用模态综合法建立其运动微分方程。计算了列车以不同车速通过时轨道梁的动力响应，并与实测结果和不考虑轮胎侧偏特性的模型做了比较。计算结果表明：考虑轮胎侧偏特性的模型的计算值及变化规律更接近实测值；研究竖向耦合振动问题时可不考虑轮胎的侧偏特性，研究横向耦合振动问题时应该考虑侧偏特性的影响。

关键词: 桥梁工程, 跨座式单轨交通, 车辆-轨道梁耦合振动, 侧偏特性