Prevention of RCF damage in curved track through development of the INFRA-STAR two-material rail

Results from the European 5th frame research project ‘INFRA-STAR’ are presented. The goal of the project is to prevent rolling contact fatigue (RCF) and to reduce squeal noise in curves by applying an additional surface layer material on the top of the railhead, resulting in a two-material rail. In INFRA-STAR, a dynamic train–track interaction model is used to provide the contact forces. Wheel-rail profiles, wheel-rail friction, vehicle data, track data and operating conditions are included to calculate the wheel-rail contact forces and spin moments, contact positions and load distributions in the contact patch. The contact pressure, friction coefficient, coating thickness, material properties of the coating and the rail material are used in finite element calculations and shakedown theory to calculate shakedown limits, which are then used to predict the RCF performance of the system. The paper details the work on theoretical modelling, twin disc testing, metallurgical research and field testing completed to date (August 2002, the project just passed midterm). The development of the surface layer application methods that are used, and the further objectives of the INFRA-STAR project, are discussed.