Train–bridge coupled vibration and vehicle running safety of the rapid maglev transit under crosswind

Abstract

Urban maglev transit, renowned for its high ride comfort and environmental friendliness, has expanded from intra-city operation to intercity services, substantially increasing its exposure to crosswind. However, the vibration characteristics and underlying mechanisms of the wind–vehicle–bridge system under crosswind remain poorly understood, and no operational regulations currently exist. This gap underscores the necessity for in-depth investigation. In this study, the 25 m simply supported beam was selected as the research subject. A coupled dynamics model of the maglev train–track–bridge was then developed and experimentally validated. Subsequently, simulations were conducted to analyze the coupled vibration characteristics and law of the maglev train–track–bridge system under crosswind. Using maglev vehicle’s dynamic responses as key evaluation indices, critical limits for train speed and wind velocity ensuring safe and stable operation of the maglev train were established. Results indicate that train speed of 120 km/h and the crosswind velocity of 20 m/s, the dynamic responses of the track and bridge change only slightly, whereas those of the train increase markedly. Crosswind predominantly intensifies the lateral displacement and roll motion of maglev train. The lateral displacement of the electromagnet and air spring increases from 3.6 mm to 9.78 mm and from 2.95 mm to 20.8 mm, respectively. The carbody roll angular acceleration rises from 0.05 rad/s² to 0.45 rad/s², indicating that roll motion substantially exacerbates carbody vibration. The wind velocity has the most significant impact on guidance gap fluctuations and air spring lateral displacement. When the wind velocity is below 21.9 m/s, maglev train can run safely at the design speed of 120 km/h; for wind velocity between 21.9 m/s and 24 m/s, the train speed reduction is required; and for wind velocity above 24 m/s, suspension of the urban maglev transit is recommended.