ABSTRACT
An integrated computer design method has been developed for fatigue life prediction of railway vehicle bogies. In principle, there are five parts in the procedure: specification and measurement of track geometry data; assembly of a suitable vehicle computer model and specification of rail/wheel profiles; description of dynamic suspension load time histories; evaluation of stress distribution in the bogie frame and stress histories of the critical areas; the fatigue life prediction of the bogie.
The whole procedure has been applied to a typical four-axle metro vehicle. A comprehensive set of track irregularity data obtained from a track recording vehicle using on-board instrumentations has been used. The dynamic behaviour of the vehicle and the stress distribution of the bogie frame have been analyzed. The fatigue life prediction of the bogie has been calculated from the dynamic stress histories in the bogie critical areas using the cumulative damage theory. The results have been compared against field test data and show good agreement with operational data from the actual vehicles.
It has been shown that the proposed design methodology for railway vehicle bogies, based on real track profiles on which they will run and on their own structural characteristics, is feasible and can be used at an appropriate vehicle design stage.
