Fatigue research for rotating mirror of ultra-high speed camera through numerical analysis and experimental methods

It is the major failure mode of high-cycle fatigue for rotating mirror. Test methods for fatigue are commonly used in researching the fatigue life of rotating mirror, but not practically. In this paper, numerical analysis and experimental were used for researching the fatigue life of rotating mirror. With the finite element analysis software ANSYS, a static strength about the rotating mirror was calculated at first and the results of stress from computing were imported into the nSoft as the cyclic stress load spectrum for analyzing the fatigue life of rotating mirror. According to the S-N curve of rotating mirror which defined by the material properties, the Miner linear cumulative damage law and the Goodman Mean Stress Correction Model, the fatigue life of rotating mirror was calculated by nSoft. It shows that the fatigue failure of rotating mirror does not occur under the speed of 3x10(4) rpm, because no node is damaged within the threshold of infinite numerical cycles in that speed. Then a fatigue life experiment was done. 10 specimens of rotating mirrors worked for 360 minutes respectively in the speed of 3x104 rpm on the bench of the rotating mirror test system. The cycle index of stress was more than one million times, and no fatigue failure was occurred for every last sample. The results from the numerical are in accord with that from experimental analysis. It is high accurate to analyze the fatigue life of the rotating mirror by the method of numerical analysis.