Wheel-rail contact:: Roughness, heat generation and conforming contact influence

The reliability of the dynamic railway simulations is completely conditional upon the precision with which the wheel-rail contact problem is solved. This is because most of the external forces the rail vehicle is subjected to during circulation are transmitted through this contact. To solve this problem, normally a series of assumptions are made (non-influence of the surface roughness, non-influence of the heat generated on the contact, etc.) in order to obtain an efficient solution to the problem. However, it must be pointed out that the possible influence of some of these simplifications has not been analysed whereby a detailed investigation is required permitting an evaluation of the order of magnitude of the errors related to these simplifications. In this work, the influence of the following assumptions in the resolution of the wheel-rail contact problem shall be thoroughly analysed: assumption of smooth surfaces, assumption of noninfluence of thermal effects and assumption that the dimensions of the contact are much lower with respect to those of the curvature radii of the surfaces. (C) 2008 Elsevier Ltd. All rights reserved.