A new numerical simulation method of 3D rough surface topography with coupling 3D roughness parameters Sdr, Sdq, Spd, Spc, and characteristic functions

The existing surface topography modeling methods based on random process theory make it difficult to realize the coupling of three-dimensional roughness parameters Sdr, Sdq, Spd, and Spc in ISO25178, which are related to the friction and lubrication performance of parts. The paper proposes constraints set for the structure of spatial features in height matrix discrete points during the random switching process, and the accurate coupling of parameters Sdr, Sdq, Spd, and Spc with characteristic functions is achieved by the improved random switching system. The new method is applied to simulate four kinds of finishing surface topography numerically, and the results show that the relative errors of these four parameters are effectively reduced from 5–110 % to 1 %.