A computational analysis of the application of skewness and kurtosis to corrugated and abraded surfaces

摘要

In this work, we describe the results of our investigation into the relevance of skewnessudand kurtosis as measures of surface roughness. Two types of surfaces are computationallyudgenerated: abraded surfaces consisting of surface scratches, and corrugatedudsurfaces consisting of hemispherical features. It was found that abraded surfacesudcould be well described by the skewness and kurtosis, which can both be specified byudthe degree of coverage by the features on a surface. These two parameters showeduda large variation over the range of surfaces sampled. The root mean squared (RMS)udslope and surface area ratio did not change significantly by comparison, and the RMSudroughness changed significantly only for surfaces with a large variation of scratchuddepths. A monotonic relationship was found to exist between skewness and kurtosisudfor abraded surfaces composed mainly of smaller scratches. For corrugated surfaces,udthe skewness and kurtosis were nearly constant for surfaces with RMS roughness valuesudthat differed significantly. The RMS roughness, RMS slope, and surface area ratio changed significantly by comparison. No monotonic relationship was found betweenudthe skewness and kurtosis for corrugated surfaces. This indicates that corrugatedudsurfaces are best described by the RMS roughness, RMS slope, and surface area ratioudrather than the skewness and kurtosis.