Abstract: Many types of engineering surfaces are observed to exhibit fractal characteristics. This means the surfaces possess the properties of statistical self-similarity and self-affinity. To realize comprehensive and multi-scale characterization of the engineering surfaces, a composite surface assessment approach is presented. In this approach, a zooming index term is established based on the fractal dimensions that are shown to be the intrinsic parameters of the surfaces. Based on the zooming index, composite wavelet models for the surfaces are established. The form errors, the waviness, and the roughness can then be obtained and assessed conveniently. The results of the composite assessment of the surfaces obtained from the simulation tests are demonstrated the effectiveness of the proposed method.

Key words: Composite characterization, Fractal theory, Surface topography, Wavelet transform