Fatigue properties of railway axles: New results of full-scale specimens from Euraxles project

Abstract

Euraxles project was a European Research project brought over under the 7th European Frame Work and promoted by the European association of Railway Wheelsets manufacturers. The present paper is a dissemination of the main results achieved during the full-scale axles fatigue test campaign in which various axles configurations were tested. This experimental activity was part of the work package 3 of the Euraxles project.The main scope of WP3 was to provide new fatigue limits for the Standard steel grades considering also the effect of surface conditions that may be different from the normal newly machined axles, like surface corrosion that can appear during the service or surface blasting as a method to improve paint adhesion.The areas of the axles considered were the free body transitions or groves and the wheel seats where at high bending rates relative micro slips take place generating the so called fretting fatigue phenomena.The paper provides in the conclusions a comparison with the fatigue limits that are today included in the European Standards.Another aspect that is treated in this work is the stress concentration effect that takes place along the transitions where the body fatigue limit is verified. These parameters were measured by strain gauges during each test and used inside the Euraxle project to validate their estimation through FE model calculation. Also in this case a comparison is made with the stress concentration values reported in the EN Standards that appear to be underestimated.