Fraunhofer LBF presents the lightweight wheel set HIPERWHEELnew development methodology and new materials make wheel sets for rail-bound vehicles lighter, quieter and more reliable - recommendations for EU norm In interdisciplinary co-operation with ten renowned European partners the Fraunhofer Institute for Durability and System Reliability LBF researched new methods of development for the reliable dimensioning of high performance wheel sets for rail-bound vehicles. Based on a new methodology the project partners Lucchini and Otto Fuchs developed the prototypes of the HIPERWHEEL. The advanced hybrid design combines modern steel and aluminium materials (30NiCrMo V12; AlMgSi31; 6082-T6), which allow an approx. 25 % reduction in weight, compared to standard steel wheel sets. The HIPERWHEEL will be used predominantly in the European regional and suburban traffic. The market volume in this sector by 2009 will amount, according to a study of the consulting firm SCI Verkehr GmbH - "European Operator Market for Short- Distance Passenger Traffic" – up to € 4.9bn.
For the development of a methodology that is valid Europewide extensive fundamental research was carried out. These resulted in the conclusion, that the decay of the fatigue strength under contact fatigue is different in the “Wöhler-” and the “Gaßner”-test. “Wöhler”-tests rely on constant force amplitudes whereas “Gaßner”-tests are based on variable force amplitudes during durability tests. For wheel sets this means that a reliable lay out design is only possible with tests under near-service conditions. The striking point for the new wheel set methodology, which considers modern materials, compound techniques and manufacturing processes, was the comprehensive experimental and numeric identification of the operation loads on different railway networks, so realistic near-service conditions could be created.
The final analysis of the HIPERWHEEL was carried out in the worldwide unique LBF wheel set test rig, by means of programmed durability tests on a virtual test track. The stress analysis was optimized experimentally and by numeric simulation with the LBF®.WheelStrength software. In the tests an optimised version of the wheel set reached 70.000 kilometres, which is equivalent to a life span of approximately 10 million km. The project is based on a broad, interdisciplinary field of research and covers among other things the
The test results confirm the development methodology for a reliable lay out design of new wheel sets, so that serious deficits in the European standards UIC 510-5, EN 13104 and EN 13261, in particular for new wheel sets with modern materials, compound techniques and manufacturing processes, can be overcome.
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