A NON-LINEAR MODEL OF A TWO-AXLE RAILWAY VEHICLE

Mathematical models of railway vehicles were developed in the course of earlier studies at Saab-Scania AB during the period 1970-1976. These permit stability analysis of small-perturbation dynamics of vehicles with separate axles, with bogies and with double bogies. One model was also programmed for a hybrid computer system and allows time history simulation. The purpose of the present study is to develop a mathematical model of a two-axle freight car running on flexible track. The wheel/rail contact forces and the axle suspensions are represented by non-linear functions, as are the track irregularities. The mode will be implemented on a hybrid computer system. The fully developed hybrid simulator will be run with known track data. The results will be used for comparison with the behavior of the corresponding real freight car running on the same track.