Abstract
For the investigation of fatigue failure of actual components, the requirement of estimation of service load from fracture surface is increasing. In this research, method to estimate not only stress amplitude but also stress ratio is proposed. Fourier analysis is applied to the cross section profile of striation observed on the fatigue fracture surface in the method It is considered that the frequency where the power spectrum is strongest indicates the striation width. Also the power spectrum is considered to relate to the striation height The method is applied to the fracture surface obtained by the fatigue test. In the test, ΔK was constant Material was Aluminum alloy (2024-T3). The striation's profile is measured by the laser microscope. In the result, the striation whose width is 0.5〜2μm is detected by Fourier analysis. And the strongest power spectrum is related to stress ratio.
