Résumé
This paper presents the time course of the heat source distribution accompanying high cycle fatigue of metals. The full-field temperature measurements obtained by quantitative infrared thermography are used to derive the thermoelastic source amplitude and the mean dissipation over a loading cycle. For significant signal-to-noise ratios, the calorimetric analysis of the temperature fields gives a quite homogeneous distribution of the coupling sources while a strongly heterogeneous dissipation field occurs, since the very beginning of the fatigue test and for any stress range, stress ratio and/or loading frequency. The narrowing of the fatigue localization zones and the increase of the corresponding dissipation intensity are shown at different stress ranges. Different dissipation vs. stress range curves are finally shown at different stages of the sample fatigue life. The gradual drift of these curves (and not the curves themselves) are associated with the kinetics of the fatigue progress from an energy standpoint.