Wear of machine parts is an important problem in operating life of machines. Rationalwear and running-in procedures are able to machine parts improve in conformity, surface topog-raphy and frictional compatibility dur...Wear of machine parts is an important problem in operating life of machines. Rationalwear and running-in procedures are able to machine parts improve in conformity, surface topog-raphy and frictional compatibility during usage, therefore improving machine reliability and pro-longing its operating life. Hence, it is necessary to study the topography characterization of thesurfaces of friction pairs and its change laws in wear or running-in process. This paper appliesfractal theory to study the characterization of the worn surface topographies of friction pairs duringthe initial stage of wear process. Experimental researches show that the fractal parameters of thesurface topographies of friction pairs will reach their steady-state values, respectively, with thewear process going on. And the variations of the fractal parameters have corresponding laws fortwo samples of friction pairs.展开更多
Fractal geometry is increasingly becoming a useful tool for modeling and quantifying the complex patterns of natural phenomena. The Earth's topography is one of these phenomena that have fractal characteristics. T...Fractal geometry is increasingly becoming a useful tool for modeling and quantifying the complex patterns of natural phenomena. The Earth's topography is one of these phenomena that have fractal characteristics. This paper investigates the relative sensitivity of topography to active tectonics using ASTER Global Digital Elevation Model. The covering divider method was used for direct extraction of surface fractal dimension(D surf) to estimate the roughness-surface of topography with aid of geographic information system(GIS)techniques. This evaluation let us highlight the role of the geomorphic and tectonic processes on the spatial variability of fractal properties of natural landforms.Geomorphic zones can be delineated using fractal dimension mapping in which variability of surface fractal dimension reflects the roughness of the landform surface and is a measure of topography texture. Obtained results showed this method can be a quick and easy way to assess the distribution of land surface deformation in different tectonic settings. The loose alluvial deposits and irregularities derived by tectonic activity have high fractal dimensions whereas the competent formations and higher wavelength folded surfaces have lower fractal dimensions.According to the obtained results, the Kazerun Fault Zone has a crucial role in the separation of the Zagros Mountain Ranges into the different lithological,geomorphological and structural zones.展开更多
文摘Wear of machine parts is an important problem in operating life of machines. Rationalwear and running-in procedures are able to machine parts improve in conformity, surface topog-raphy and frictional compatibility during usage, therefore improving machine reliability and pro-longing its operating life. Hence, it is necessary to study the topography characterization of thesurfaces of friction pairs and its change laws in wear or running-in process. This paper appliesfractal theory to study the characterization of the worn surface topographies of friction pairs duringthe initial stage of wear process. Experimental researches show that the fractal parameters of thesurface topographies of friction pairs will reach their steady-state values, respectively, with thewear process going on. And the variations of the fractal parameters have corresponding laws fortwo samples of friction pairs.
基金the Research Council of Shiraz University which has supported the project
文摘Fractal geometry is increasingly becoming a useful tool for modeling and quantifying the complex patterns of natural phenomena. The Earth's topography is one of these phenomena that have fractal characteristics. This paper investigates the relative sensitivity of topography to active tectonics using ASTER Global Digital Elevation Model. The covering divider method was used for direct extraction of surface fractal dimension(D surf) to estimate the roughness-surface of topography with aid of geographic information system(GIS)techniques. This evaluation let us highlight the role of the geomorphic and tectonic processes on the spatial variability of fractal properties of natural landforms.Geomorphic zones can be delineated using fractal dimension mapping in which variability of surface fractal dimension reflects the roughness of the landform surface and is a measure of topography texture. Obtained results showed this method can be a quick and easy way to assess the distribution of land surface deformation in different tectonic settings. The loose alluvial deposits and irregularities derived by tectonic activity have high fractal dimensions whereas the competent formations and higher wavelength folded surfaces have lower fractal dimensions.According to the obtained results, the Kazerun Fault Zone has a crucial role in the separation of the Zagros Mountain Ranges into the different lithological,geomorphological and structural zones.
