Application of the normalization method for the determination of J–R curves

The performance of the normalization method (NM) is evaluated and compared with the standard unloading-compliance method of fracture-toughness analysis for a broad spectrum of different materials and specimen geometries. The critical J-integral values based on the normalization method are summarized and compared with the results of unloading compliance tests. The results demonstrate the applicability of the normalization method for the J–R curve determination for a range of steels. The normalization method yields results, which deviate as much as 15% from the values obtained with the unloading compliance method, and thus results of acceptable accuracy can be attained with this method.