Firstly

the surface roughness data of a test-piece are measured by a roughness profile measuring analyzer. By using of the Fourier transform nonlinear approximation method

the measured data are used to build a roughness function which is then added to the oil film thickness equation and a gearing mixed elastohydrodynamic lubrication model is established. Based on this model

46 groups numerical calculation of mixed elastohydrodynamic lubrication are carried out through changing the date of roughness when gearing parameters and other lubricant parameter are fixed. The computing results show that

with the film ratioKincreased

the ratio of the vertical stripes average film thickness hav/has is gradually increased and in the last approaching to 1

on the contrary

the transverse stripe decreased and in the last approaching to 1. At the end

the quantitat ive relationship between hav/ has and the film ratioKare created based on the regression analysis of the above 46 groups calculational results.