FRACTAL DIMENSION OF FRACTURE SURFACE FORMED BY SLOW CRACK PROPAGATON INDUCED BY HYDROGEN
氢致裂纹慢扩展区断裂表面的分维研究

Fractal dimension of different parts of a fracture surface formed by slowcrack propagation induced by the combining effect of hydrogen and static bending momentwere determined by using the method of fracture profile analysis.The results show that thefractal dimension increases with increasing transgranular fracture which increases as thecrack propagates.This means that the increase of the fractal dimension responds to the in-crease of the energy needed to form the fracture surface and the process of forming a frac-ture surface by slow crack propagation is the one of increasing fractal dimension of thefracture surface;when the fractal dimension reaches a critical value,the crack propagationbecomes unstable.