Thesis deals with the spectral analysis of 3D surface topography. The surface is described by a random function. Theoretical starting points necessary for right introduction and understanding of basic notions used within the framework of the surface topography spectral analysis are exactly formulated. They lie in the theory of random functions, the theory of the Fourier transform and the theory of signal processing. The notions mentioned are: the areal power spectral density (APSD) of a surface, the radial power spectral density (RPSD) of a surface and the angular power spectrum density (AnPSD) of a surface. These notions are introduced in their discrete form and generalized for the two-dimensional case. The thorough discussion of possible mistakes and inaccuracies which can be done during the application of spectral analysis techniques in a surface topography evaluation is performed. The procedure of APSD estimation by means of the periodogram method combined with the Welch´s method is discussed. The principle and capabilities of the optical profilometer MicroProf?FRT used for the surface topography measurement are described. Our original computer program computing APSD, RPSD and AnPSD is described too. The 3D spectral analyses is applied to surfaces generated by AWJ cutting, plane grinding and casting. We have focused our attention to AWJ cut surfaces, 3D spectral analyses of which brings new still unpublished opportunities of the surfaces topography evaluation. The influence of technological parameters on these AWJ cut surfaces topography is studied. The conclusion of the study is that results of the spectral analyses of these surfaces topography strongly depend on the technological conditions of the surfaces generation. An original procedure of the ASPD shape evaluation within individual regions of its frequency domain is mentioned. This procedure brings new substantial knowledge concerning the topography of surfaces. Results obtained from surfaces generated by plane grinding and casting are presented like examples of results from non-isotropic and isotropic surfaces.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:233970 |
| Date | January 2011 |
| Creators | Brillová, Kateřina |
| Contributors | Valíček, Jan, Hloch,, Sergej, Ohlídal, Miloslav |
| Publisher | Vysoké učení technické v Brně. Fakulta strojního inženýrství |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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