Key parameter selection of suspended monorail system based on vehicle–bridge dynamical interaction analysis

This study aims to select the proper key parameter values of suspended monorail system (SMS) by analysing the vehicle–bridge dynamical interaction. First, a coupled dynamical model of vehicle–bridge system is established by using ANSYS parameter design language (APDL). Further, the car-body accelerations obtained by the proposed model and field test are systematically analysed in frequency domain. A sensitive parameter influencing the vehicle ride comfort is identified. The key parameter value of the bridge is selected with the objective to improve the vehicle-bridge vibration level. Finally, accounting the out-of-round tyre, the dynamical performance of vehicle and bridge is investigated under periodic harmonic disturbance, and proper values of secondary suspension parameters of vehicle subsystem are selected. Results show that the space between bridge stiffeners is a sensitive parameter that can aggravate the car-body acceleration. This space is finally suggested to be 1.2–1.4 m in order to effectively reduce the vehicle-bridge dynamical interaction. Controlling the vertical stiffness of secondary suspension to be less than 0.2 MN/m, the periodic harmonic disturbance can be effectively isolated. To ensure a reasonable vibration level of vehicle–bridge system suffering from periodic harmonic disturbance, the vertical damping of secondary suspension is suggested to be about 27 kN·s/m.