Fatigue crack growth in full-scale railway axles – Influence of secondary stresses and load sequence effects

A wheel-set axle is located in the unsprung part of a rail vehicle and takes a supporting role in the running gear. If the wheel-set axle fails, the train will inevitably derail. Depending on the time of failure, this can lead to catastrophic consequences. For this reason, a wheel-set axle is a highly safety-critical component of railway vehicles. Detailed knowledge of crack propagation in wheel-set axles is therefore of great importance for a modern safety concept. To analyse the material behaviour under external loads approximated from operating conditions, experimental investigations were carried out on 1:1 specimens. This article presents the results of these experimental investigations carried out within the framework of the research project “Eisenbahnfahrwerke 3 (EBFW 3)” – “Probabilistic Fracture Mechanical Concept for the Assessment of Railway Wheel-sets”.