Abstract
Concept of "Fractal" can be usefully applied to evaluate the irregularity of geometrical shape, profile of time-dependent phenomena and so on. Three dimensional geometry of fracture surface for any metallic material has such an irregularity which is governed by the fracture mechanisms. Geometrical irregularity of the fracture surface of SUS304 steel failed in the rotating bending was evaluated by means of the fractal analysis. Since the striation on the fracture surface has a significant orientation, anisotropy should be introduce to the analysis. It was found that this kind of anisotropy can be well evaluated by the fractal analysis proposed here.
