Railway wheelset fatigue life estimation based on field tests

Field tests using an instrumented powered wheelset were performed to investigate fatigue damage accumulation in railway axles. Axle bending strains were measured and post-processed to obtain axle stress spectra. Statistical analyses were used to investigate the variations of axle stress spectra due to changes in railway operation parameters. The study indicates that measured axle stress spectra can be modeled using truncated normal distributions, where the large majority of measured stress amplitudes are lower than 50 MPa. Stress cycles at higher amplitudes are affected by operation parameters such as track design, number of switches and crossings, and whether the wheelset is in a leading or trailing position. Variations in the obtained statistical distributions of axle stresses have been used as input for fatigue life analyses. It was concluded that fatigue damage can potentially initiate on axles suffering from corrosion or small surface cracks/scratches.