The impact of non-Gaussian height distributions on the statistics of isotropic random rough surfaces

Abstract

The impact of non-Gaussianity on the statistical geometry of isotropic random rough surfaces is analysed in this contribution. The non-Gaussian height distribution is modeled using the Weibull probability distribution. The summits height distribution, expected mean curvature and density of summits are obtained and compared with analytical solutions given by Nayak’s theory for the Gaussian case. A significant deviation from the Gaussian cases is observed. The mean curvature of negatively-skewed surfaces is found to decrease with the increase of height, contradicting the trend registered for the Gaussian case. Nayak’s parameter globally dominates the impact of the spectral properties. However, the wavelength ratio and the Hurst exponent are required to characterize the effect of the spectrum on the rough surfaces statistics.