用高阶矩谱表征粗糙表面的偏斜程度

Characterization of the Skewness of Rough Surface by High-order Moment Spectrum

基于双谱分析理论,结合表面粗糙度偏斜度参数的定义,提出了偏斜度函数的表达方式,以及二维双谱的对角线切片算法,并将它们用于三维粗糙工程表面的偏斜度描述。文中还对具有对称、正偏态和负偏态分布特征的电火花、精密车削和研磨加工试件进行了实验研究,认为双谱和偏斜度函数可以合理有效地描述三维粗糙表面偏离高斯分布的程度。

Based on the bispectrum analysis technique and the definition of roughness parameter ——skewness, the expression of surface skewness function and the algorithm of twodimensional bispectrum by diagonal slice is described. Subsequently the skewness function and the diagonal slice bispectrum have been applied to describe the amplitude distribute character of three dimensional rough engineering surface. The skewness of some representative machining surfaces have been analyzed, such as symmetrical surface generated by Electron Discharge Machining (EDM), positive skewed by fine turning and negative by lapping. The analysis results show that bispectrum and skewness function can be used to describe the departure from Gaussian distribution of three dimensional rough surface reasonably and effectively.