2021 Volume 107 Issue 11 Pages 934-943
A method to automatically search brittle fracture initiation point is proposed. The method calculates flow paths from each edge of an image to opposite side along flow potential. The potential is derived from the direction of river-pattern and tear ridge. The most concentrated position of flow paths is determined as a fracture initiation point. The method achieves 99% precision and high speed analysis for low magnification images of 206 thick plate samples. Furthermore, discriminating ductile fracture by machine learning and excluding noise potential obtained from it, and considering local feature of river-pattern that spread radially near a fracture initiation point, the method precision is improved for high magnification images. Using fractal feature of brittle fracture and repeatedly applying the method, a fracture initiation point is determined within the size of a single grain level.
