tailieunhanh - Handbook of Lubrication Episode 1 Part 4

Tham khảo tài liệu 'handbook of lubrication episode 1 part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Volume II 61 NOMENCLATURE awn AntiWear Number logi0k logi0 1 k A Area of apparent load support Ar Area of asperity load support Aw Area being worn B Surface profile correlation distance c Width of load support area in direction of motion d Depth of material worn from surface E Relative effective elastic modulus 2 E 1E 2 E 1 E 2 Young modulus of elasticity 1 Poisson ratio 2 FP Fs Plowing friction force shear friction force f fb fss Friction coefficient beginning and steady-state friction coefficients h Thickness of rheodynamic film between asperities H Hardness of surface in stress units multiply Brinell Knoop or Vickers hardness numbers by to convert to MN m2 MPa from the normal hardness number units which are kg force mm2 k kb kss Wear coefficient beginning and steady-state wear coefficients L Face width of line contact b Sliding distance break-in sliding distance n Number of times surface passes through loaded area P Apparent pressure on load support area W A Pe Pp Average pressure on elastically plastically deformed asperity r Asperity tip radius U Sweep velocity of surface through load support area Us Sliding velocity vector difference of sweep velocities of two surfaces through load support area V Volume of material worn from a surface V Us sliding speed W Load normal to load support area n Viscosity A Film thickness parameter ratio of fluid film thickness to composite rough- ness of wearing surfaces or to diameter of particles in fluid film if they are larger than three times the composite surface roughness Ơ Root mean square surface roughness for two surfaces in contact composite roughness is square root of sum of squares of the RMS roughness of the two surfaces T Shear stress ty Plasticity index REFERENCES 1. Bowden F. P. and Tabor D. The Friction and Lubrication of Solids Oxford University Press London 1954. 2. Archard J. F. Wear theory and mechanisms. ASME Wear Control Handbook Peterson M B. and Winer W. O. American Society of Mechanical Engineers .