Вестник Научно-исследовательского института железнодорожного транспорта (Apr 2023)
Effects of rail canting on the contact stress and pressure in the wheel–rail system
Abstract
Introduction. An urgent task today is to optimise the interaction between rolling stock and the railway track. A solution to it will increase train speed, enhance the safety and service life of wheels and rails. The service life of wheels and rails is under significant influence of contact stress and pressures. Their magnitude depends on the track geometry, including rail canting, contact spot and elastic properties of the contacting elements.Materials and methods. The authors analysed the effects of rail canting on contact stress and pressure in the wheel – rail system at various loads from the rolling stock wheels, and assessed the effects of the underrail base elasticity on deformation and stress in the contact spot ignoring the force interaction between the track and the rolling stock when the overall stiffness of the track changes. Thus, this work sets the magnitude of the forces transmitted from the wheels of the rolling stock to the rails as the input data for determining the stress-strain state of the wheel – rail system. For the analysis, the authors developed a finite element model for calculating the stress-strain state of the wheel – rail system at various compaction degrees of the underrail base. The analysis of the obtained calculated data led to conclusions about the influence of the underrail base elasticity and the canting on the contact stresses and pressures in the wheel – rail system. The authors also assessed the effects of rail canting on the stress-strain state of the wheel – rail system for deviations from the standard position within the allowed limits.Results. The calculation results show that the change in the underrail base elasticity has a weak effect on contact pressures and stresses (excluding the effect on the immediate force interaction of the rolling stock and the track). At the same time changes in the canting within the allowable values from 1/12 to 1/60 causes the contact stresses to exceed the yield strength of the rail steel, which, among other reasons, reduces the durability of the material and, as a result, reduces the service life of the rails, and, at the same time, increases the risk of brittle fracture in the area of extreme mechanical stress.Discussion and conclusion. The obtained results of the calculation show that such a parameter of the rail track as canting requires control, since a change in the stress-strain state of the rails due to a change in canting affects their service life and traffic safety in general. It is suggested to automated and manual diagnostic tools to monitor this parameter.
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