A review is presented of dynamic modelling of railway track and of the interaction of vehicle and track at frequencies which are sufficiently high for the track's dynamic behaviour to be significant. Since noise is one of the most important consequences of wheel/rail interaction at high frequencies, the maximum frequency of interest is about 5kHz: the limit of human hearing. The topic is reviewed both historically and in particular with reference to the application of modelling to the solution of practical problems. Good models of the rail, the sleeper and the wheelset are now available for the whole frequency range of interest. However, it is at present impossible to predict either the dynamic behaviour of the railpad and ballast or their long term behaviour. This is regarded as the most promising area for future research.

Modelling of Railway Track and Vehicle/Track Interaction at High Frequencies

A review of the modelling of wheel/rail noise generation

During the last years railway companies have observed increasing problems with track damage like rail corrugation, deterioration of ballast or unround wheels. Since the origin of these damages is suspected in the mid-frequency dynamics, research activities in the frequency range from 50 up to 500 Hz have been initiated. The article demonstrates that in comparison to the low and high frequency range the knowledge about physical effects in the mid-frequency range is poor. Apart from a historical literature review on vehicle and track modelling, recently published methods and models are collated and problems in their mathematical treatise are mentioned. Regarding the vehicle, the paper shows the development starting with Klingel's massless wheelset model and ending with sophisticated elastic multibody system models. Concerning the track, different mathematical approaches in frequency and time domain are compared. In the mid-frequency range the pad, ballast and subsoil properties play an important role. Hence...

Vehicle-Track Dynamics in the Mid-Frequency Range

The role of high positive friction (HPF) modifier in the control of short pitch corrugations and related phenomena

A study is presented of the non-linear dynamic interaction between a wheel and rail, excited by rough-ness on the wheel and rail contact surfaces. A moving irregularity model is used to represent the wheel/ rail interaction process in the time-domain. A low order multiple degree-of-freedom system is developed to approximate the infinite track for numerical simulations. The effects of the non-linear contact on the wheel/rail dynamic interaction are investigated through calculations, analysis and comparisons with the results from a linear contact model. The difference between the non-linear and linear interactions is found to be small if the roughness level is not extremely severe and a typical static contact preload exists. The difference increases for low preloads or for high roughness amplitudes. For example, if the wheel and rail surfaces are in good condition (r.m.s. amplitudes of roughness below 15 mm), the linear model can be used without significant error for all static loads down to 25 kN (equivale...

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U. Fingberg

Papers

A model of wheel-rail squealing noise