A Comparison of Analytical and Experimental Performance Data for a Two-Axle Freight Car

Abstract

The dynamic performance of a two-axle lightweight freight car has been determined through a combined analytical and experimental program. A fourteen degree of freedom vehicle model has been developed, employing nonlinear damping and stiffness suspension elements and nonlinear geometric and creep force wheel/rail interaction models. Analytical results have been compared with experimental field test data. Dynamic vehicle simulations agree closely with field test data for operation on vertical and crosslevel perturbed track. Simulations of the vehicle operating on curved and laterally perturbed track are in reasonable agreement with field test data in predicting performance trends for conditions approaching wheel climb derailment limits. Precise predictions of vehicle performance under wheel flanging conditions require detailed knowledge of local wheel/rail profiles and friction level.