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The mechanical and thermo-physical properties of a coating material affect the lubrication performance. The present study aims at to investigate the effect of mechanical and thermo-physical properties of coating material on the lubrication performance of rolling contact operating under Thermal Elasto-Hydrodynamic Lubrication (TEHL) regime. The mechanical and thermo-physical properties of the coating material considered in the present analysis are elastic modulus, density, thermal conductivity and specific heat. Furthermore, the effect of coating thickness is also studied. The Commercial Multiphysics software ANSYS is used in the present analysis to model and analysis of the finite line contact obtained in the rolling contact. It is observed that the pressure intensity increases with the elasticity of the coating. The maximum fluid pressure developed at the contact region 1.2GPa with the application of material possessing higher modulus of elasticity i.e. 420 GPa. With increase in coating thickness the contacts width reduces. The material having lower density, thermal conductivity and heat capacity exhibits as an insulating material which obstructs the transfer of heat from the fluid to the contacting surfaces. This leads to increase the temperature of the lubricant. With these properties the maximum developed temperature observed to be 351K. [ABSTRACT FROM AUTHOR]

An accurate structural assessment of rails under combined effect of fatigue and corrosion prevents a phenomenal disaster, also saves millions of dollars and people's lives. Recent studies which are proposed to simulate a precise model fail to take into account the different underlying mechanism for rail corrosion. The current study presents a numerical procedure to investigate crack initiation under combined effect of fatigue and corrosion. A three-dimensional (3D) finite element model (FEM) which accounts for rolling contact stresses due to wheel-rail contact loads is developed. Then, stress distribution is used in a MATLAB code to estimate the fatigue crack initiation life. The advantage of the proposed model is considering the combined effect of rolling contact fatigue and corrosion on structural integrity of rails. This model is applied to a case study of rail assessment in Melbourne, Australia. The cracks orientations and locations which were based on the FEM results were in good agreement with the field observations. [ABSTRACT FROM AUTHOR]

The paper presents steady isothermal elastohydrodynamic lubrication (EHL) of elliptical contact with Roelands pressure–viscosity model over varying rotational speed. The governing Reynolds and film-thickness equation for elliptical contact in roller bearings are analysed by using multigrid method with full approximation scheme. The non-dimensional pressure distribution and film-thickness for elliptical contacts are obtained. The distinct friction models appropriate to lubricants in contact regions are predicted. The result shows that rolling contact weariness does not occur on the surfaces with longitudinal roughness and wear or scraping exists in circular EHL contacts with entrainment along major axis to that of minor axis. The computation predicts that minimum film thickness, central film thickness and elastic deformation increase as the rotational speed increases. The computed results are compared with earlier finding which are in good agreement. [ABSTRACT FROM AUTHOR]