Triennial Report 2003 - CHARMEC

Interaction of train and track – Samverkan tåg/spår (TS) – Wechselwirkung von Zug und Gleis – Interaction entre le train et la voieTS1. CALCULATION MODELS OF TRACK STRUCTURESBeräkningsmodeller för spårkonstruktionerBerechnungsmodelle für GleiskonstruktionenModélisation de constructions des voies ferréesProject leaderand supervisorAssistant supervisorProfessor ThomasAbrahamsson,Solid Mechanics(now Applied Mechanics)Docent Jens Nielsen,Solid Mechanics(now Applied Mechanics)Doctoral candidate Mr Johan Oscarsson(from 1996-01-01;Lic Eng March 1999;PhD April 2001)Period 1996-01-01 – 2001-06-30Chalmers budget Stage 1: ksek 1400(excluding university Stage 2: ksek 2000+200basic resources) Stage 3: ksek 650Industrial interests Stage 1: ksek 400in-kind budget Stage 2: ksek 700(Banverket) Stage 3: –The analysis and design of track structure, with rails, railpads,fasteners, sleepers, ballast and substructure, forman area of central interest to charmec. Our earlier developedsimulation model in the diff (Swedish acronymfor Dynamic Interaction of Vehicle and Track) computerprogram has been expanded in the ts1 project so asbetter to reproduce the dynamics of the ballast and subgrade.Measured non-linearities in railpads and ballast/subgrade have been taken into consideration. diff hasalso been supplemented so that stochastic realizations oftrack models can be made by use of a perturbation technique.Based on the measurements in the spring of 2000at Grundbro on the Svealand Line, it was found that thescatter in railpad stiffness makes the largest contributionto the variance of the wheel/rail contact force. See furtherthe charmec Triennial Report from Stage 2.Johan Oscarsson successfully defended his doctoraldissertion (see below) on 20 April 2001. The facultyappointedexternal examiner was Dr Søren R K Nielsenof the Department of Structural Engineering at AalborgUniversity in Denmark. All of the five appended papersin the dissertation have now been internationally published.Since May 2001, Johan Oscarsson has beenemployed by the consultancy TrainTech EngineeringSweden (now sold to Interfleet Technology Ltd) inStockholm.Mikael Hallqvist: Track/vehicle simulation with explicitFE-code, MSc Thesis EX 2000:5, Chalmers Solid Mechanics,Gothenburg March 2000, 58 ppJohan Oscarsson: Dynamic train-track interaction – linearand non-linear track models with property scatter, DoctoralDissertation, Chalmers Solid Mechanics, Gothenburg April2001, 130 pp (summary and five appended papers)Johan Oscarsson: Dynamic train-track interaction – variabilityattributable to scatter in the track properties, Vehicle SystemDynamics, vol 37, no 1, 2002, pp 59-79Johan Oscarsson: Simulation of train-track interaction withstochastic track properties, Vehicle System Dynamics, vol 37,no 6, 2002, pp 449-469Johan Oscarsson: Dynamic train-track-ballast interaction withunevenly distributed track properties, Vehicle System Dynamics,vol 37, supplement, 2002, pp 385-396Jens Nielsen and Johan Oscarsson: Simulation of dynamictrain-track interaction with state-dependent track properties,Journal of Sound and Vibration (accepted for publication)Stochastic track model in project TS1. Variables taken ashaving a statistical spread are pad stiffness k p (i) , ballast stiffnessk b (i) , ballast mass M b (i) and sleeper spacing L iJohan Oscarsson of project TS1.Photo taken 2000 in the laboratoryof Chalmers Solid Mechanics14