An application of the J-integral engineering approach to blunt notch specimens

Abstract

The influence of notch root radius on crack growth resistance behaviour (J-Resistance curve) of a C-Mn structural steel was investigated by fracture mechanics experiments with three-point bending specimens. J-R Curves was determined by the multiple specimen technique and it was found that, while the J-integral at initiation is differently affected by small and large notch root radii, the tearing modulus, on the contrary, is independent on notch root radius.

The J-R curves have also been obtained by applying the estimation scheme developed by Kumar, German and Shih to evaluate the crack driving force; the estimation scheme was also utilized to evaluate the loading behaviour of both cracked and blunt notched specimens. The comparison between predictions and experimental results has generally shown a good accordance, thus extending the applicability of the J-integral engineering approach to blunt notch specimens.