PARAMETRIC ANALYSIS OF THE HUNTING OF A FREIGHT CAR TRUCK ON THE NRC CURVED TRACK SIMULATOR

The development of experimental facilities for rail vehicle testing at the NRC Centre for Surface Transportation Technology is being complem ented by analytic studies. The purpose of this effort has been to gain insight into the dynamics of rail vehicles in order to guide the deve lopment of the Curved Track Simulator (CTS) and to establish an analyt ic framework for the design and interpretation of tests to be conducte d on the CTS. The work described here represents an initial effort tow ards meeting these objectives. Parametric study using linear model of freight truck on the CTS showed that (a) increasing roller radius incr eases critical speed (b) increasing the wheel initial cone angle will decrease the hunting speed (c) increasing the roller cant increases hu nting speed (d) decrowning of the wheelset on the rollers will not eff ect the hunting speed but induces longitudinal destabilizing horizonta l forces at the contact and (e) lozenging of wheelset on the rollers i nduces a yaw moment and the hunting speed decreases with increasing wh eelset yaw angle.