The longitudinal harmonic vibrations found in the suspended monorail train (SMT) seriously affected the ride quality and dynamic behaviour. In this work, the experimental and simulated analyses are carried out to reveal the essential phenomenon, occurring mechanism and possible solutions to this issue. Firstly, the ride quality and vibration transmission of the tested SMT system are investigated. It is found that the longitudinal vibrations with the frequency of 2.7Hz occur to the carbody, bogie frame and suspension of the train system. Due to the secondary suspension is lower than the gravity center of the bogie frame, the bogie pitch motion with low damping ratio can be easily excited. The longitudinal components of the bogie pitch motion will transfer to the carbody and wheelset through traction rod and primary suspension, respectively. After that, the multibody dynamic model of a suspended monorail train is developed. Based on the numerical model, some parametric simulations, e.g. rubber stiffness, traction rod height and secondary damping, etc., are carried out to propose solutions to relieve the longitudinal vibrations. Finally, the field tests for the SMT arranging the longitudinal dampers are conducted to verify its improvement to longitudinal vibrations.

在悬挂式单轨列车 (SMT) 中发现的纵向谐波振动严重影响了乘坐质量和动态行为。在这项工作中，进行了实验和模拟分析，以揭示该问题的基本现象、发生机制和可能的解决方案。首先，研究了被测SMT系统的乘坐质量和振动传递。结果表明，列车系统的车体、转向架框架和悬架发生频率为2.7Hz的纵向振动。由于二级悬挂低于转向架框架的重心，容易激发低阻尼比的转向架俯仰运动。转向架俯仰运动的纵向分量将分别通过牵引杆和主悬架传递到车身和轮对。之后，建立了悬挂式单轨列车的多体动力学模型。在该数值模型的基础上，进行了橡胶刚度、牵引杆高度、二次阻尼等参数化模拟，提出了缓解纵向振动的解决方案。最后，对设置纵向阻尼器的 SMT 进行了现场测试，以验证其对纵向振动的改进。