The Response of a New Lightweight Rail Track System (LR55) to Various Loading Environment

Abstract

The finite element method is used to determine the response of a new lightweight rail track system (LR55) to various loading environments. To calculate the vertical displacement of the rail track system and the vertical pressure in the sub-base and sub-grade layers due to wheel loads and loads exerted by transversely passing vehicles across the track, the global stiffness matrix of the structure is determined. This is done by using one and two dimensional finite element programs. In the two dimensional finite element analysis, linear isoparametric elements with 4-node quadrilateral and 3-node triangular shapes in the discretised mesh of the whole structure are used, also non-homogeneous materials with isotropic of linear elastic behaviour are assumed for all the components forming the track system and surrounding media. The results of the one dimensional finite element program are compared with those predicted from analytical approach in order to validate the finite element program developed. From the various examples presented the LR55 proves to withstand the main-line railway loading and the vertical pressure distribution in the sub-base and sub-grade of the pavement are within the allowable limit.