Methodology for the formation of rail repair profiles by grinding

The formation of a rail transverse profile to reduce contact loading and wear from railway rolling stock wheels is one of the main tasks of rail grinding. At present, when designing a rail grinding technology, a future rail profile contour is selected from a set of repair profiles available in a database. Frequently, the profile selected from the database is less than optimal, as it does not provide the required interaction in the wheel-rail system for a particular track section, and its formation requires excessive metal removal, which reduces the rail's lifespan. The paper proposes a new methodology for designing rail repair profiles based on a fundamentally new approach, consisting in designing rail geometric parameters at the stage of preparing the technological process of its grinding. This approach to the rail grinding technology design allows specifying a geometric profile for the certain railway track operating conditions and the worn rail condition, thus bringing metal removal from a rail head to required minimum and, as a result, increasing the service life of rails and the performance of a rail grinding train. To assess the efficiency and applicability of the proposed method for different railway track operating conditions, a comparative modelling of the existing approach in selecting a rail repair profile with the proposed approach to its design was carried out. The proposed method showed the best result in all cases.