AN ENGINEERING APPROACH FOR NOTCH ELASTIC-PLASTIC FRACTURE-ANALYSIS

In this paper, the J-integral path-independence of a notch under incre mental theory, the possibility of measurement of notch J-integral frac ture toughness, and the equality in numerical values between the notch and the crack J-integrals, are investigated and demonstrated by means of elastic-plastic finite element analysis. Based on this, the author s deem that the J-integral may also play the role of a main parameter for notch elastic-plastic fracture analysis. Meanwhile, based on the n otch J-integral numerical calculation, the authors further establish t he notch failure assessment curve, and therefore investigate the depen dence of the failure assessment curve on the dimension and geometry pr ofile of the notch end and the feasibility of the R6 (third edition) f ailure assessment curve in the notch assessment. The method of the fai lure assessment diagram should be regarded as a simple and convenient engineering failure assessment approach for notch elastic-plastic frac ture analysts, which can give the possible failure mode of the notch. The notch fracture toughness, J(A), is no more a simple material const ant. the engineering estimation method for the notch fracture toughnes s is expounded in this paper, which should lay the foundation of appli cation of the notch failure assessment diagram.