Fractal evaluation aspects in characterizing the roughness of a driving wheel from a locomotive

Abstract

For comprehending tribological phenomena such as wear, friction, contact deformation and tightness of contact joints is the essential characterisation of the multiple scale topography of roughness surfaces. Wheel roughness obtained through direct measurement and then a description of wheel roughness has been obtained using the fractal function. The statistical parameters and fractal sizes for drive wheels which ran 2000 km and another ones new wheels have been analysed.By registering the results and programmable automaton of the roughness, the principal statistical characteristics were determined to be stands out the Abbott-Firestone curve and respectively, the fractal character. The appearance of roughness on the surface of the wheel causes the production of vertical vibrations that act on the complex wheel-rail system.In the analysis of the wheel irregularity, the fractal geometry was applied, so that to obtain the fractal parameters Dw, respectively Ltw (opothesy length), the method of the structure function was used [1, 2]. Therefore, the experimental measurement and obtained results processed presented.

Wear calculation and life prediction model of disc brake based on elastoplastic contact mechanics

“…9 Babici et al found that the fractal function can describe the surface roughness. 10 It is vital to monitor the evolution of such a wear process through investigating the worn surface. Compared with traditional two-dimensional methods, three-dimensional measurements of worn surfaces can provide more information.…”