Résumé
This communication is dedicated to the presentation of an experimental setup developed to estimate the energy dissipated during high cycle fatigue tests (VHCF). VHCF tests are performed at very low stress ranges, generally under the conventional fatigue strength. To reduce the duration of tests, the cycling loading is performed at a frequency of about 20 kHz. The experimental set-up uses ultrasonic techniques to generate such a dynamic loading and an infrared thermographic system to capture the temperature fields at the flat specimen surface. An infrared image processing is proposed to estimate the heat evolved using inevitably under-sampled thermo-signals and taking into account the different heat exchanges between the specimen and the surroundings. The calorimetric analysis being associated with microstructural investigations, pure copper specimens are used, focusing on the development of slip bands considered as the main source of energy dissipation. The very first calorimetric results are shown and discussed.