Analysis of Ride Comfort of a High-Speed Train Based on a Coupled Track-Train-Seat-Human Model with Lateral, Vertical and Roll Vibrations

To study the ride comfort of a high-speed train running at a constant speed on a tangent track, a 3D rigid-flexible coupled track-train-seat-human model was developed. The flexible carbody model consisted of six plates with out-of-plane and in-plane vibrations interconnected by artificial springs, and was calibrated using a modal test available in a published paper. The ride comfort was evaluated by total equivalent acceleration calculated by the weighted root-sum-of-square of the weighted root-mean-square of lateral, vertical and roll accelerations at the feet, seat-buttock and human-backrest interfaces. It was concluded the track rigidity had the most influence on lateral, vertical and roll vibrations of the floor above 16 Hz, but had no obvious influence on ride comfort. The flexible carbody model showed intensified floor vibration in lateral, vertical and roll directions above 8 Hz compared with the rigid one, so rigid carbody model caused great underestimation of total equivalent acceleration. The total equivalent acceleration showed increasing tendency as increasing speed. For symmetrical seat positions, the equivalent accelerations showed analogous tendency as the speed. The ride comfort at the carbody center and close to the ends was the worst. Regardless of the seat position and speed, vertical acceleration on the seat pan was the most severe, followed by the vertical acceleration at the feet. The neighbouring subject usually resulted in reduced total equivalent acceleration. The damping of the carbody effectively reduced the total equivalent acceleration for every speed. The effect of the suspension stiffness and damping on ride comfort was also studied.