Numerical Simulation of Wheel-rail Interfaces in Heavy Freight Corridors using Hybrid Rigid-deformable Model. (2018) - Khan, M.R.
Abstract: Design and operation of dedicated railway freight corridors require detailed analysis of the arduous loading conditions imposed by trains during heavy load transit. A hybrid rigid-deformable numerical model is formulated for estimating the increase in wheel-rail frictional stresses, contact pressures, equivalent von-Mises stresses and strains produced in the axle, corresponding to an increase in the applied axle load. The hybrid model considers the wheel-rail system to be a combination of deformable wheel-set running on rigid rails, which considerably reduces the computational demands and time associated with the analysis of large number of nodes and elements in the numerical model. Validation of the model was done by analyzing a section of Italian rail UNI-60 and contact pressure results were correlated with the data available from literature. Wheel-rail contact analyses were then performed on Indian Railways IRS-52 track section, for heavy axle loads upto 32.5 tonnes, as proposed by Indian Railways for dedicated freight corridors. A Hertzian elliptical contact patch was observed at the wheel-rail interface. Assessment of contact pressure and frictional stresses were then done at the wheel-rail interfaces for a load range of 20 to 32.5 tonnes, and it was noted that the increase in pressures were non-linear, with a quadratic trend. The variation in stresses and strains induced in the axle during loading could also be estimated, since wheel-set was modelled to be deformable in nature. The model analyses are expected to be useful to the railway authorities for designing rail and wheel sections to cater the intense loading conditions in dedicated freight corridors.