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 compliances 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 e attained with this method.