Rail-Wheel Geometry Associated with Contact Stress Analysis

摘要

This report records the derivation of a number of results pertaining to wheel and rail geometry that are needed for the analysis of contact stresses and rolling-creepage phenomena. In particular, results utilized in the authors' computer programs COUNTACT (for COUNTerformal contACT problems) and CONFORM (for CONFORMal contact problems) are given. It is shown how the profile curves specified by engineering drawings for standard wheels and rails may be analyzed to find appropriate parameters needed to express the pertinent equations in the various coordinate systems used in contact stress analysis. For arbitrarily selected points of initial contact on the wheel tread and on the railhead, it is shown how to determine the feasibility of such contact, and how to determine the mutual separation of points on the two surfaces. It is also shown how to determine the curve of interpenetration which is used as an initial estimate of the contact patch boundary associated with a given relative approach (due to elastic deformation) of the loaded wheel and rail. The basis of a computer program (MIDSEP) to determine this separation is described.