A 3D model for coupling dynamics analysis of high-speed train/track system

Abstract

A 3D dynamic model of a high-speed train coupled with a flexible ballast track is developed and is presented in this study. In this model, each vehicle is modeled as a 42 degrees of freedom multi-body system, which takes into consideration the nonlinear dynamic characteristics of the suspensions. A detailed inter-vehicle connection model including nonlinear couplers and inter-vehicle dampers, and the linear tight-lock vestibule diaphragm is established to simulate the effect of the end connections of neighboring vehicles on dynamic behavior. The track is modeled as a traditional three-layer discrete elastic support model. The rails are assumed to be Timoshenko beams supported by discrete sleepers. Each sleeper is treated as an Euler beam and the ballast bed is replaced by equivalent rigid ballast bodies. The reliability of the present model is then validated through a detailed numerical simulation comparison with the commercial software SIMPACK, with the effect of the track flexibility on the train/track interaction being analyzed simultaneously. The proposed model is finally applied to investigate the difference between dynamic performances obtained using the entire-train/track model (TTM) and the single-vehicle/track model (VTM). Several key dynamic performances, including vibration frequency response, ride comfort, and curving performance, calculated by the two types of dynamic models are compared and discussed. The numerical results show that there is a significant difference between the dynamic behaviors obtained by VTM and TTM, and that inter-vehicle connections have an important influence on the dynamic behavior of high-speed vehicles.

Key problems faced in high-speed train operation

“…The modelling considers the vertical, horizontal, and longitudinal dynamic behavior coupling of high-speed train and track. Ling et al (2014) in this special issue models the connections between adjacent vehicles of the train and the effect of the connections on the vertical and horizontal behavior. The analysis of vehicle stability, comfort and safety index has greatly improved, but we still lack understanding of the influence of the train longitudinal behavior, including acceleration, deceleration, vertical extrusion, collision, stretching, deformation and longitudinal wave, and structural characteristics, including train length, length of vehicles, and carriage longitudinal stiffness (Ling et al, 2014).…”

“…Zhong et al (2014) in this special issue considers the effect of wheels with 3-8 order polygonal wear on the wheel/rail rolling contact since the polygonal wear is much related to the wheelset 1-3 order bending resonances occurring when the train operates at high speeds. Ling et al (2014) considers the influence of rail and track slab flexible deformation. However, because of the difficulty of the problem and computing limitations, the present rigid-flexible coupling modeling cannot consider the whole system of vehicle-track, and is only local in scope.…”

Modeling and analyses of a connected multi-car train system employing the inerter

“…The effects of inter-vehicle connections are studied based on multi-body dynamics theory. For instance, Ling et al 11 discussed the impacts of vehicle connections on the dynamic behavior of train models. They compared the dynamic performances of the single-car and the multicar train models without the inerter.…”

Reproduction method of the relative position and posture of vehicle ends on the test bench

“…M Ansari et al 6 studied the effects of the stiffness and damping of the couplers on the longitudinal freight train dynamics. Ling et al 7,8 established a three-dimensional (3D) train-track coupling model with detail models of inter-vehicle connections and studied the effect of inter-vehicle connections on the vehicle performance by comparing with the results of single vehicle-track coupling model. The above researches are carried out by simulation analysis and difficult to simulate the actual operation of the train.…”