Title: Application of SQP and dynamic mode tracking to the determination of the critical speed of rail vehicles

Authors: Yuping He, John McPhee

Addresses: Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, Oshawa, Ontario, L1H 7K4, Canada. ' Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada

Abstract: A method is presented for determining the critical speed of rail vehicles. Dynamic Mode Tracking (DMT) is used to identify the dynamic modes for a given speed and a Sequential Quadratic Programming (SQP) algorithm determines the critical speed at which the least-damped mode has zero damping. It is shown that the SQP algorithm without DMT often fails to find the critical speed. In comparison, the combined SQP-DMT algorithm provides a reliable identification of the critical speed. This integrated algorithm can be applied to rotor dynamics, wind turbine dynamics, aeronautics, and road vehicle dynamics for automatically identifying the critical speed corresponding to a linear stability analysis.

Keywords: sequential quadratic programming; SQP; dynamic mode tracking; DMT; critical speed identification; rail vehicles; linear stability analysis; lateral stability; heavy vehicles; railways.

DOI: 10.1504/IJHVS.2007.013261

International Journal of Heavy Vehicle Systems, 2007 Vol.14 No.2, pp.193 - 212

Published online: 14 Apr 2007 *

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