Abstract
A numerical solution for line contact elastohydrodynamic lubrication (EHL) occurring on the rough surface of heterogeneous materials with a group of particles is presented in this study. The film thickness disturbance caused by particles and roughness is considered into the solution system, and the film pressure between the contact gap generated by the particles and the surface roughness is obtained through a unified Reynold equation system. The inclusions buried in the matrix are made equivalent to areas with the same material as that of the matrix through Eshelby’s equivalent inclusion method and the roughness is characterized by related functions. The results present the effects of different rough topographies combined with the related parameters of the particles on the EHL performance, and the minimum film thickness distribution under different loads, running speeds, and initial viscosities are also investigated. The results show that the roughness morphology and the particles can affect the behavior of the EHL, the traction force on a square rough surface is smaller, and the soft particles have more advantages for improving the EHL performance.
Highlights
E contact components with inhomogeneities have been investigated by many researchers. e heterogeneous particles distributed in the matrix can be described as a domain that has the same material properties as the matrix but with eigenstrains [1] through the equivalent inclusion method (EIM) proposed by Eshelby [2]. en, to solve the contact problem of inhomogeneous materials, a semianalytic solution for inhomogeneous inclusions with arbitrary shape in an isotropic half space under contact loading through the EIM was proposed by Zhou et al and is widely used [3]. e contact pressure and the subsurface stress field for the contact problem of anisotropic elastic inhomogeneities with ellipsoidal shape were analyzed by Koumi et al [4]
Zhu presented a numerical solution of the effects of the surface roughness on the pressure spike and the film constriction [16]. e surface roughness could affect the distribution of film thickness and pressure and destroy the film in the lubricated contact, which may cause mixed lubrication [17, 18]. e interaction of asperities and friction force in the movement of a lubricated contact can be affected by the roughness, and this is disadvantageous for the improvement of an elastohydrodynamic lubrication (EHL) environment workings under a heavy load [19]
E following conclusions can be drawn from the study: (1) e minimum film thickness of EHL on the same rough surface is reduced compared to that in a smooth surface. e central film thickness is reduced and is smaller than that of the outlet area as the hardness of the particles is increased
Summary
It is well known that the EHL film thickness is very thin, which makes the film sensitive to the deformation and morphology of the contact surface. E surface roughness could affect the distribution of film thickness and pressure and destroy the film in the lubricated contact, which may cause mixed lubrication [17, 18]. E performance of the EHL film thickness, pressure, and shear force between oil and the contact surfaces are related to the surface topography and the material properties. Erefore, considering the influences of both inhomogeneous materials and surface rough topography on EHL, it is meaningful to explore an effective method to reduce the friction of heavy-load lubricated contacts and improve the lubrication environment in actual production. According to the principle of EIM proposed by Eshelby [2], the inhomogeneous particles can be equivalent to an area that has the same elastic modulus as that of the matrix but subject to eigenstrains e. According to the elastic field of the Eshelby problem, the displacement of the response point (x1, x2) caused by particles inside the matrix can be written as
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
