Spatial Distribution Characteristics of Rail Vibration Acceleration under Train Load

A vehicle-track dynamic model and track-substructure finite element model were established to study the basic parameters and sensitive areas of rail vibration, respectively, when a train passes. The models were developed based on the co-simulation of MBS software GENSYS and finite element software ABAQUS. The wheel-rail forces from the vehicle-track model were used as the excitation source in the track-substructure model, and the effects of train speed, track irregularity, and different types of track supports on rail acceleration were analyzed. The research results show that rail acceleration decays from the head to the foot of a rail, and the acceleration of the rail head above the sleepers is significantly greater than that between the sleepers. The acceleration of the rail head is sensitive to speed. For a ballastless track, as the traveling speed increases from 200 km/h to 350 km/h, the rail head acceleration increases from 1.476 km/s² to 2.980 km/s². The rail acceleration of a continuously supported ballastless track is less than that of the traditional, discrete supported ballastless track. The installation of acceleration sensors outside the rail head is recommended. The frequency and range selection of the sensor should be made taking into consideration the train speed, track irregularity, and other factors.