Dynamic Analysis of Resilient Crosstie Track for Transit System

Abstract

A dynamic analysis of a new track system, developed for a light rail transit vehicle powered by linear induction motors (LIMs) is made by a specially developed computer package. The track system, which incorporates steel crossties, is modeled by the finite-element method, while the vehicle is modeled separately as a combination of masses, springs, and dampers. The two models, which are linked through wheel loads, are applied to at-grade guideways in a study of the influences of a number of parameters on the dynamic behavior of the track and on the variation of the LIM air gap. The important parameters include vehicle-track interaction, nonlinearity, and stiffness of the tie pads, rail surface profile, and vehicle speed. The dynamic distributions of the LIM and wheel loads among the crossties are also discussed. It is shown that both the surface profile of the rail and the vehicle-track interaction affect the displacement response of the track significantly, while the wheel loads are mainly affected by the rail profile.