An effective secondary suspension system for isolating the high-frequency vibrations of suspended monorail vehicle running on a flexible track beam

Abstract

ABSTRACT Secondary suspension system is a core component of a suspended monorail vehicle (SMV), which plays a vital role in suppressing the car-body vibrations. This article aims to investigate the vibration isolation performance of an external secondary system (ESSS) for the SMV. Firstly, the structural features and mechanical mechanism of the ESSS are elaborated, which are compared with those of an existing internal secondary suspension system (ISSS) in the SMV. Then, an effective analysis method for the vehicle-track beam interaction of the suspended monorail system (SMS) is established based on the rigid-flexible coupling dynamics theory, in which the main modal information of the track beam is considered. Furtherly, applying the established analysis method, the vehicle-track beam vibrational responses between the ISSS and ESSS are compared under the local irregularity of beam-end junction and random track irregularity, and the superiorities of adopting the ESSS are revealed. Finally, by comprehensively considering the vehicle-track beam vibrational responses, several crucial parameters of the ESSS are selected appropriately. Results show that the ESSS has a significant advantage in isolating the high-frequency vibrations of the SMV compared with the existing used ISSS; simultaneously, it could also effectively decrease the track beam vibration. To guarantee good vehicle riding comfort, the vertical stiffness and damping with the ESSS are recommended to be 0.05∼0.2 MN/m and 10∼30 kN·s/m, respectively. Highlights ➢ Structural features and mechanical mechanisms of an effective ESSS for the SMV are introduced. ➢ A high-efficiency analysis method for vehicle-track beam interaction of the SMS is established. ➢ By a comparison with the commonly used IEEE, the advantages and significance of the ESSS are revealed ➢ Several crucial design parameters of the SMV with ESSS are selected appropriately.