Fatigue tests on wheelset under simulated service stress spectra.

In this paper a procedure is presented that was applied for wheelset components during the development of a light-weight wheel from Schwäbische Hüttenwerke (SHW). The procedure requires knowledge of the actual wheel forces that occur in service with respect to magnitude, frequency of occurence and also their correlation in time. These forces were determined for an inter-city train and were used to derive characteristic cumulative frequency of occurence distributions for a service life of 5 mill.kilometers. The data were also used to determine a load programm for prooftests regarding adequate service life in the existing test facility for wheelsets. Based on the above mentioned test-load program, fatigue strength tests can be carried out under typical and important loading conditions such as: straight run, concerning, passage over switches and sinusoidal running for all component-parts of the wheelset, i.e. wheel, hub, bolted connection, and the axle. Also described in the paper are the development of a light-weight wheel and the results of the tests that led to the optimally shaped and dimensioned wheel design. Achieved was a reduction of 30% in weight compared with standard wheel as well as improved dynamic vehicle behaviour. Finally a further advanced test procedure and a description of a new test facility for proof-testing of service life is presented. (LBF)