Statistical analysis of asperities on a rough surface

Main asperities on isotropic rough surfaces are analysed using their two-dimensional characteristics: the altitude of each asperity’s summit and its radius. Each of these geometrical characteristics is described using statistical analysis with probability density functions such as Gaussian or lognormal laws. These distributions are redimensioned with characteristic values deduced using the recent standard procedure for roughness and waviness parameter determination in accord with the so-called “motif” procedure. After a short review of the standardised procedure for determining roughness and waviness parameters, we present a detailed description of the characteristic values — mean and root mean square — of the dimensional parameters and their distributions. Finally, we apply the model herein developed using measurements from three different types of microgeometry ranging from quasi-periodic to quasi-random.