TRACK GEOMETRY MODELING FOR RAIL VEHICLE STUDIES.

This paper discusses a general model of track geometry for rail vehicle dynamic simulation studies. The model characterizes both deliberate work changes, such as track curvature and superelevation, and unintentional changes due to track irregularities. The deliberate track changes represent inputs which permit the simulation of the dynamic response of vehicles during curve entry, negotiation, and exit. The unintentional variations are used to model stochastic track inputs, such as alignment, gauge, and crosslevel irregularities, and to represent deterministic inputs due to rail joints and other phenomena. The general track model is coupled with a vehicle dynamic curving simulation routine that can be used to study the performance of vehicles with different suspension designs and wheel profiles operating on a variety of track environments. Here, selected simulation results of vehicle dynamic response due to track geometry variations are presented.