Computational Modeling of Fatigue Performance of an Integrated Crosstie System for Advanced Rapid Transit

This paper presents the fatigue behavior of an integrated crosstie system for an Advanced Rapid Transit (ART). The crosstie system consists of steel base plates welded to a hollow structural section, and a concrete guideway slab. The steel-wheeled ART is operated by linear induction motors (LIM) and provides a unique load configuration to the crosstie system, including electromagnetic force and gravity load. To absorb dynamic effects from the ART, elastomeric pads are placed under the base plates. A three-dimensional finite element analysis is conducted to examine the fatigue performance of the crosstie, on the basis of cumulative damage theory. The study focuses on stress progression, displacements, and stress concentrations in the crosstie system subjected to fatigue load of up to three million cycles. The effect of pad deterioration on the fatigue behavior of the crosstie is evaluated. Design recommendations to improve the sustainability of the crosstie system are discussed.