Journal Article

Dynamic evaluation on ride comfort of metro vehicle considering structural flexibility

Zhu, Guo, Chen, Zhaowei

2021

Overview

Traditional rigid vehicle model cannot reflect structural local vibration and flexible deformation, which may affect the accuracy in evaluating ride comfort of metro vehicle. Aiming at this issue, this paper proposes a research method of flexible dynamic behavior based on flexible multi-body dynamics (FMBD), considering the structural flexibilities of key parts of metro vehicle in detail, to study the ride comfort of metro vehicle. First, finite element models of carbody and frame are established, which are then reduced by substructure theory and Guyan reduction method. On this basis, the flexible vehicle-track coupled dynamic model is established. After investigating the difference between the flexible model and traditional rigid model, the ride comfort of metro vehicle on straight line and curve line is then evaluated subjected to rail random irregularity, short-wave excitation and long-wave excitation, respectively. Finally, correlations of carbody vibrations at different locations are deeply investigated. Results show that carbody accelerations calculated by flexible model are larger than those obtained by rigid model. The sensitive frequency band of human is obviously reflected and calculated by flexible model, indicating that the ride comfort of metro vehicle can be more accurately evaluated with the flexible vehicle model. Flexible modes and local vibrations are obviously reflected in carbody vibrations. Vibration at PR (point on roof) location is largest, and vibration at PC (point on floor center) location is smallest. Ride comfort is very sensitive to long-wave excitation while is not sensitive to short-wave excitation. It is not accurate enough to evaluate ride comfort of metro vehicle only according to vibration at floor center, and more data at different locations should be concerned, especially vibrations at air spring locations.

• Publisher: Springer London,Springer Nature B.V
• Subject: Accuracy / Air springs / Bending stresses / Civil Engineering / Dynamic models / Efficiency / Electrons / Engineering / Finite element method / Flexibility / Floors / Frequencies / Mechanical Engineering / Methods / Original Article / Passenger comfort / Straight lines / Structural Materials / Vehicles / Vibration / Wave excitation