Defect assessment for pressure vessels considering crack growth and strain hardening

In this paper, a simple approach distinguished with the EPRI assessment method is deduced. We suggest a demarcating curve for the infinite plate containing a crack considering the strain hardening effect. The double parameters assessment criteria according to the parameter oc, for crack initiation and the tearing modulus Tc, considered the crack growth are proposed to describe the two different modes of failure for the pressure vessels. The transformed formula of the relationship between the COD for the original crack tip and the δt suggested by Rice are introduced. We deduced a theoretical curve for the fracture resistance of materials with strain hardening and then the instability condition of cracked body connected to the double parameters method are discussed.