Spectrum fatigue behaviour of welded joints

A five-year study of the spectrum fatigue behaviour of welded joints is briefly reviewed. The emphasis is on test data obtained under various load spectra, but a short description of material properties, weld processes and resulting defects is included. A round robin evaluation of different test institutes involved in the programme is mentioned, and the actual spectrum data obtained are discussed in terms of a statistical analysis to isolate the important test parameters. The data are also evaluated in terms of cumulative damage calculations and using a fracture mechanics model. Residual stress relaxation during the fatigue loading was monitored using repetitive X-ray diffraction studies. Finally, an application to full-scale testing of bogie beams is commented upon. This paper does not attempt to cover the entire programme in detail, but tries to briefly cover the total approach in the performed study and also highlights certain important results that were found during the course of this study.