Triennial Report 2003 - CHARMEC

Parallel EU projects – Parallella EU-projekt – Parallele EU-Projekte – Projets parallèles avec l’UEEU7. INFRASTARINFRASTAR – Improving railway infrastructure productivity bysustainable two-material rail developmentVerbesserte Produktivität der Eisenbahninfrastruktur durchEntwicklung haltbarer Schienen aus zwei WerkstoffenAmélioration de la productivité de l’infrastructure ferroviaire par ledéveloppement des rails durables composés de deux matériauxCoatingLaser beamProject leadersProfessor Lennart Josefson andProfessor Roger Lundén,Applied MechanicsCo-workers Docent Jens Nielsen,Applied MechanicsDr Jonas Ringsberg,Assistant Professor,Applied MechanicsProfessor Birger Karlsson,Materials Science and EngineeringPeriod 2000-05-01 – 2003-06-30(– 2003-10-31)Budget EU keuro 181Budget CHARMEC Stage 3: keuro 2100For photos of project leaders and co-workers, see pages19, 38, 41, 43 and 49The infrastar project of the Fifth Framework Programmecomprises a total of 140 man-months with abudgeted project cost of keuro 1780 and a budgetedeu funding of keuro 1080. Chalmers/charmec’s commitmentto infrastar is 20 man-months. Partnersare aea Technology Rail (the Netherlands), Banverket(Sweden), Chalmers Applied Mechanics/charmec(Sweden), Duroc (Sweden), Inexa Profil (Sweden, onlyto September 2001), ratp (France), Corus (France)and the Department of Mechanical Engineering at Universityof Sheffield (uk). The duration of the infrastarproject is 42 months and it is co-ordinated by aea TechnologyRail.The aim of the infrastar project is to increase theoperational life and reduce the emitted noise of particularlyexposed sections of railway track, such as smallradiuscurves subject to large traffic volumes and highaxle loads. The application of an extra surface layer tothe railhead is investigated. Two different technologiesare being studied: the melting of powder onto the surfaceby means of a laser beam, and the rolling-in of an extralayer of material on the bloom during rail manufacture.One objective is to develop and validate a predictivemodel that can assist coating selection in the design ofa fatigue-resistant two-material rail. We have participatedin meetings with the project partners at Arlanda,Gothenburg and Luleå (Sweden), at Manchester andComputer-generatedrendering of lasercoating of gaugecorner of rail(courtesyDuroc Rail)Sheffield (uk), at Metz and Paris (France) and at Utrecht(the Netherlands).We have established rigid-body models of trains onMalmbanan (the Iron Ore Line in northern Sweden)and on the Paris underground. Dynamic simulations oftrains running on curves have been performed with theaid of the commercial computer program gensys, whichcalculates the contact forces between wheels and railand where on the railhead contact takes place. Full-scaletests have been performed on Malmbanan and the Parisunderground on stretches where laser-cladded rail hadbeen installed in the track.Three-dimensional finite element calculations of thestress field in the railhead at the contact patches betweenwheel and rail have been performed by us. Shakedowndiagrams have been designed for the laser-cladded rail incollaboration with the University of Sheffield. The riskof initiation of rolling contact fatigue cracks can thusbe estimated on the basis of such parameters as contactpressure, friction coefficient, thickness of surface layer,and material properties of the surface layer and the basematerial. A full finite element simulation of the lasercladdingprocess to quantify the residual stress field andits effect on the initiation of fatigue cracks is under way.Measurements of the residual stresses in twin-disc experiments(as performed in Sheffield) by use of straingauges and centre hole drilling have been carried out byus but were complicated by the extreme hardness of thesurface layer.Martin Hiensch, Ajay Kapoor, Lennart Josefson, Jonas Ringsberg,Jens Nielsen and Francis Franklin: Two-material raildevelopment to prevent rolling contact fatigue and to reducenoise levels in curved rail track, Proceedings 5th World Congresson Railway Research (WCRR 2001), Cologne (Germany)November 2001, 16 pp on CD. At the congress this work wasawarded the prize for best paper in its category→56