A single test method for evaluation of the J integral as a fracture parameter

Abstract A semi-analytical method for the evaluation of the Rice fracture parameter J is presented. The method is such that a value of J may be determined from a single load-displacement test record, and procedures are set out, together with appropriate equations, for evaluating center cracked sheets, compact tension specimens and single edge notched beams. The method utilizes the elastic stress intensity relationships in conjunction with a modified form of the Irwin plastic zone size correction factor. Tests were carried out on center cracked sheets and compact tension specimens manufactured from a high strength aluminium alloy of a thickness (3.2 mm) for which conditions of plane stress prevailed. The J values are shown to be dependent on specimen dimensions. The results are compared with those obtained by a graphical procedure. Some anomalies are noted and comparison of center cracked sheets with compact tension specimens discussed.