Research on Vibration Characteristics of a Flexible Vehicle-Ladder Track System

As a means of vibration reduction, the ladder track has seen broad implementation in urban rail transit. However, issues such as increased vibration noise, rail corrugation, and fastener failure have been observed in certain sections of the ladder track during later operation. To investigate the mechanisms behind these phenomena and provide comprehensive insights into the system's response to various operational conditions, this study employed vehicle-track coupled dynamic theory to establish a three-dimensional finite element model of the flexible vehicle-ladder track system. The vibration transmission and dynamic response characteristics of the vehicle-ladder track system were analyzed. The findings revealed that the vehicle-track resonance and anti-resonance phenomena were more prominent in the medium- to low-frequency range. At specific frequencies, the wheelset exhibited various vibration modes, and the fastener force was found to closely correlate with the ladder vibration mode. Furthermore, the influence of speed on diverse components of the vehicle-ladder track system, in terms of maximum vibration and the dominant vibration frequency range, differed considerably. This study provides a more comprehensive and reasonable exploration of the modeling and dynamic behavior of vehicle-ladder track systems.