Portal de Periódicos da CAPES

Description of surface roughness as an approximate self-affine random structure

1995; Elsevier BV; Volume: 331-333; Linguagem: Inglês

10.1016/0039-6028(95)00157-3

1879-2758

O.I. Yordanov, K. Ivanova,

Adhesion, Friction, and Surface Interactions

We describe surface roughness as a random profile with finite domain, power-law power spectrum. These profiles have recently been shown to exhibit approximate self-affinity. In contrast to the frequently employed fractal models, our approach accounts for the fact that real surfaces possess a wide-range, yet finite, hierarchy of roughness scales. The existence of smallest and largest scales could, in general, considerably alter the dimension of the surface (compared to the idealized fractal analog), thereby leading to errors in the estimation of the statistical parameters of the surface. The adequacy of the proposed model is demonstrated using existing experimental data for the autocovariance function of rough metal deposits. The fit of our model to these data render values of the following statistical parameters of the surfaces: the similarity exponent, large and small scale rms heights, the topothesy, and the large scale correlation length.