Mechanical and thermal parameters for high-cycle fatigue characterization in commercial steels

In the present paper, the fatigue behaviour of two commercial steels has been investigated by means of thermal and mechanical measurements on specimens during fatigue testing. In particular, the investigated parameters are the surface thermal increment of the specimen and the hysteresis loop area along with the corresponding integrals of the two parameters for a number of cycles. An analytical description was firstly presented, focusing on the relations between surface temperature and hysteresis area. To both verify the theoretical relationships and emphasize the fatigue damage behaviour, an experimental procedure has been set up for mechanical and thermal parameters monitoring. Results have been finally compared in terms of fatigue limit estimation and fatigue parameters evolution.