Heterogeneous structures with inhomogeneous inclusions under elastohydrodynamic lubrication contact with consideration of surface roughness

Abstract

In order to predict the microscopic response of surface coatings and subsurface inhomogeneous inclusions, a semianalytical solution is developed for heterogeneous materials subjected to elastohydrodynamic lubrication contact. In this solution, the inhomogeneous inclusions are homogenized according to Eshelby's equivalent inclusion method with unknown eigenstrains to be determined. The topmost coating is assumed as an inhomogeneous inclusion of finite size and thus simulated with the same methodology. The disturbed surface deformation due to the presence of coatings and inhomogeneous inclusions are iteratively introduced into the lubricant film thickness until a convergence is achieved. The effects of surface roughness on the pressure and film thickness profiles and subsurface elastic fields are considered to approach the engineering practice. This solution takes into account the interactions between the loading body, the fluid lubricant and the coating/substrate system with embedded inclusions.

Multigrid solution of 2D and 3D stress fields in contact mechanics of anisotropic inhomogeneous materials

“…(2)-(4) are used to solve the top boundary displacements and pressure distribution for the contact problem satisfying the Hertz-Signorini-Moreau condition, Eq. (5).…”

“…Relatively recent examples are the Voronoi finite element model was used for damage mechanics by Warhadpande and Sadeghi [4] who observed that surface defects have a significant effect on RCF life in heavily loaded lubricated conditions. Considering surface coating, subsurface inclusions and surface roughness, Dong et al [5] developed an approach for computing the stress field distribution. In their study, both inclusions and coating were homogenized using the Eshelby's equivalent inclusion method.…”

An investigation of the elastic cylindrical line contact equations for plane strain and stress considering friction

“…20 Surface roughness 21,22 and lubrication, which do exist in real cylindrical contact applications, such as rolling element bearings and gears, are also not considered. 23 In many rolling element bearing problems, elastohydrodynamic lubrication (EHL) will occur, which is a different problem than what is considered here. However, the contact area and deformations are often in the same order of magnitude as EHL problems.…”

Thermoelastohydrodynamic Characteristics of Low-Temperature Helium Gas T-Groove Face Seals

“…Thermoelastohydrodynamic problems have always played an essential role in the precise design of gas face seals [ 1 , 2 , 3 , 4 , 5 , 6 ] and other mechanical elements [ 7 , 8 , 9 , 10 ] since both thermal distortion and elastic distortion significantly affect sealing performance. However, with the rapid development of pre-cool technology using low-temperature and high-pressure helium gas in hypersonic engines [ 11 , 12 ], there arouses a new thermoelastohydrodynamic lubrication problem, where not only the face distortions [ 13 , 14 , 15 , 16 ] but also the real-gas properties [ 17 , 18 ] become nonignorable, since compressibility coefficient, viscosity, and heat capacity vary obviously with decreasing temperature.…”