A fretting damage correction factor applicable to the McDiarmid criterion of plain high-cycle fatigue.

This paper presents an assessment of the performance of a set of multi-axial high-cycle fatigue criteria on the basis of a series of fretting fatigue experiments. We carried out tests on a creep-resistant chromium steel material used for steam-turbine blades. The first type of experiment employed the classical cylinder-on-flat geometry with flat dog-bone specimens. The second set of experiments adopted dovetail geometry. Various loads were applied in order to capture a wide range of contact slip amplitudes. A set of eight plain multi-axial fatigue criteria was applied to the numerically simulated stress response in the contacts during a single load cycle. Methods, which originated in the so-called theory of critical distances, were used for correcting the results in order to take the stress gradient effect into account. A simple factor based on slip amplitudes is introduced in order to consider the surface damage and is calibrated for the McDiarmid method. This criterion provided the best estimates of the most probable cracking sites. [ABSTRACT FROM AUTHOR]