Measurement of opening displacement and stress intensity factor of two branches of bifurcated notch by Moiré interferometry

Abstract

Static experiments on dynamic crack branching are carried out, in which Y-shaped notches in plate specimens are regarded as rapidly bifurcating cracks. Moiré interfrometry is applied to measure crack opening displacement, COD, of two branch notches as well as the mother notch of the Y-shaped notch. Stress intensity factor of the branch notches are calculated through the formula for COD of linear elastic fracture mechanics. From the measurement results, it is clarified that how far the singular stress field is developed around the branch crack tip.