In this paper,a semi-analytical calculation model for the coefficient of friction(COF)of single spherical protrusions is presented.It allows the prediction of the deformative friction part(μ_(def))and adhesive fricti...In this paper,a semi-analytical calculation model for the coefficient of friction(COF)of single spherical protrusions is presented.It allows the prediction of the deformative friction part(μ_(def))and adhesive friction part(μ_(def))of the friction pairings steel|polyethylene with ultra-high molecular weight(PE-UHMW)and polyoxymethylene(POM)|PE-UHMW.The experimental studies included unlubricated friction tests,which served to determine the total COF(μ_(def)),as well as tests being lubricated with silicone oil,from whichμ_(def)is obtained.Based on the verification tests,it could be shown that both states of lubrication result in the same deformation and that the relationship between the rear angle(w)andμ_(def)postulated in the calculation model is valid.Therefore,friction tests with segmented spheres were carried out,which allow a specific variation of thew.It can be concluded that for both pairings theμ_(def)is generally of minor significance(approx.1/3μ_(tot))and the influence of theμ_(adh)predominates(approx.2/3μ_(tot))the friction process.Furthermore themtot decreases with increasing contact pressure especially in the low pressure range and depends on the form of motion(continuous and discontinuous).展开更多
基金funded by the Federal Ministry of Economic Affairs and Energy(BMWi)through the“Otto von Guericke”German Federation of Industrial Research Associations(AiF)on the basis of a resolution of the German Bundestag as part of the programme to promote joint industrial research(IGF No.20967 BG).
文摘In this paper,a semi-analytical calculation model for the coefficient of friction(COF)of single spherical protrusions is presented.It allows the prediction of the deformative friction part(μ_(def))and adhesive friction part(μ_(def))of the friction pairings steel|polyethylene with ultra-high molecular weight(PE-UHMW)and polyoxymethylene(POM)|PE-UHMW.The experimental studies included unlubricated friction tests,which served to determine the total COF(μ_(def)),as well as tests being lubricated with silicone oil,from whichμ_(def)is obtained.Based on the verification tests,it could be shown that both states of lubrication result in the same deformation and that the relationship between the rear angle(w)andμ_(def)postulated in the calculation model is valid.Therefore,friction tests with segmented spheres were carried out,which allow a specific variation of thew.It can be concluded that for both pairings theμ_(def)is generally of minor significance(approx.1/3μ_(tot))and the influence of theμ_(adh)predominates(approx.2/3μ_(tot))the friction process.Furthermore themtot decreases with increasing contact pressure especially in the low pressure range and depends on the form of motion(continuous and discontinuous).
