Connectivity Characterization Of Three-dimensional Surface Topography Based On Image Analysis

Three-dimensional surface microstructures have great influence on the friction, lubrication and seal of surfaces. In order to investigate the relationship between surface topography and its performances and develop the functional characterization method of surface topography, we suggest a method which can be used to study the structure property and connectivity of surface topography.Based on Image Analysis, this thesis introduced two methods of connectivity measure. One is from the Euler number computation, another is multi-scale connectivity measure based on morphological operator. Detail algorithm was established for the connectivity measure. Taking the section with 80% of bearing area ratio, the connectivity of simulated laser texturing surface is calculated and analyzed, and the connectivity difference of simulated unidirectional texture, cross texture surface and laser texturing surface is compared. The variation of connectivity of different texture surfaces with the surface height is investigated. The calculated results show that the surface connectivity of laser texturing surface with dimples separated is smaller than that of dimples not separated, and its connectivity increase with the radii of dimples. When the distance between the dimples increases, its connectivity index decreases. For the same distance between dimples and the same groove width, the connectivity of cross texture surface is better than that of unidirectional texture, and for circle texture, it is in between. The small change of groove width has minute influence on its connectivity, and the increase of the distance between textures worse the connectivity of surface, and the connectivity changes with the surface height, and the connectivity become worse with decrease of height and increase of bearing ratio. The method proposed is also used to characterize the connectivity of the surface of cylinder liner, the actually value of connectivity measure is given.The method of surface connectivity measure developed in this paper provides a new mean for the characterization of valleys of surface topography, and provides a foundation for the study of lubrication property of rough surface.