Two-material rail development to prevent rolling contact fatigue and to reduce noise levels in curved rail track

Results from the European 5 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. A dynamic train-track interaction model is used to provide the contact forces. Wheelrail 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 to calculate the shakedown limit, which is then used to predict the rolling contact fatigue performance of the system. The presented paper will detail the above proposed work as well as the work on theoretical modelling, twin disc testing and metallurgical research completed to date. The development of the surface layer application methods that are used and the further objectives of the INFRA-STAR project will also be discussed. The presented paper will account for interesting and industrially relevant RCFand noise related research work. We believe that it will be of great importance in the future development of reliable and durable rail infrastructure.