An extended linear model for the prediction of short pitch corrugation

According to Grassie and Kalousek (S.L. Grassie and J. Kalousek, Proc. Inst. Mech. Eng., Parr F, 207 (1993) 57-68) for most of the corrugation problems causes and treatments are known. Only roaring rails or short pitch corrugation still are unsolved problems. This paper presents an advanced linear model for the prediction of short pitch corrugation. It bases on the idea of a feedback between structural dynamics and wear. Since the last presentation in 1990 (K. Hempelmann, F. Hiss, K. Knothe and B. Ripke, Wear, 44 (1991) 179-195), the model of the contact mechanics has been improved. The calculation of global corrugation growth rates provides an easier and better understanding of the results. Two main mechanisms of the corrugation formation have been identified. The contact mechanics provide a filter (contact filter) which suppresses the growth of very short wavelength corrugation. Stiff loci in the vertical structural dynamics, mainly of the track, cause high contact forces and lead finally to corrugation. Some results of parameter studies are presented, others and their influence on the formation of corrugation are summarized.