Numerical Simulation And Analysis Of Percolation Parameters Of Surface Topography

Because of the existence of surface peak and valley, there are irregular void between the contacted interface, which have important effects on fluid flow on the interface. This paper focuses on the measurement method of three dimensional surface microstructure’s percolation characteristics, introducing percolation characteristics to surface characterization in the form of characterization parameters, providing theoretical basis for surface percolation characteristics’evaluation, and providing the basis for introduce surface percolation characteristics to sealing leak and lubrication analysis. Surface percolation parameters presented by this thesis provide a new direction for the function of surface morphology characterization.In order to study the effect of solid surface topography on surface percolation, as well as 3D surface topography characterization parameters and images, by controlling the shape, spacing and depth, area ratio, a series of 45 steel specimens with the same surface arithmetic average height Sa and different surface microstructure were designed and manufactured by laser surface texturing. All the surfaces were measured by non-contact 3D Optical Profiler Talysurf CCI Lite and characterized by ISO 25178. On the basis of mechanical rheological model and site percolation, the article explore the representation effect of percolation on surface topography and define surface percolation characteristic parameters, besides compile the corresponding algorithm based on MATLAB software according to the parameters’ definition. By analyzing the percolation characteristic of the simulation Gaussian random surface and real surface data, the article reveal percolation rule of surface. Analyze micro-textured surface shape、depth、area ratio’s effect on surface percolation characteristic. At the same time, analyze the percolation characteristic of the simulation micro-texture surface and real micro-texture surface.Based on the curves and image analysis of surface percolation parameter, the regularities and the results indicate:no matter simulation surface or real surface, when surface height vary from valley to summit, the percolation phenomenon come up. Simulation comes at void area closed in percolation theory value 0.592746 but real original surface at 0.5. For the same surface it have different percolation characteristic when computer in different side. Meanwhile, the differentiation of textured surface bigger than the original one. Micro-texture’s shape, depth, area ratio and whether texture crossing the surface have influence on surface topography percolation characteristic.