抄録
We investigated a method to evaluate fatigue damage of steels without contact using laser speckle. In the earlier stage of fatigue, slipbands appear on a metal surface. Using this method, we are able to detect fatigue damage based on speckle pattern change due to surface property change caused by the slipbands. In this study, we investigate the relation between change of surface properties and speckle pattern during fatigue loading under constant stress amplitude. Surface roughness, frequency distribution and fractal dimension in surface profile diagrams were observed as fatigue damage increases. Parameter to evaluate fatigue damage was investigated.
