by Anders Johansson

THIS DOCTORAL thesis uses data from full-scale experiments and numerical simulations to study defects around complete wheel circumferences, as well as local defects such as wheel flats.

Tread irregularities occurring on a range of rolling stock in Sweden have been assessed using out-of-roundness measurements. These found high roughness with wavelengths between 30mm and 80mm on tread-braked wagons and X2 high speed train wheels. A previously identified polygonalisation of C20 subway wheels was quantified.

A multibody model of three-dimensional train-track interaction has been expanded to include rolling contact mechanics and long-term wear. By studying metro car wheels and rail corrugation growth some polygonalisation wavelength-fixing mechanisms related to the track properties have been identified.

Chalmers University of Technology, Department of Applied Mechanics, SE-412 96 G