Extensions of the Failure Assessment Diagram Approach Semi-Elliptical Flaw in Pressurized Cylinders—Part II

Abstract

Approximate closed-form J -integral expressions based on the estimation scheme for use in the Deformation Plasticity Failure Assessment Diagram (DPFAD) approach are presented for an axially oriented semi-elliptical flaw in a pressurized cylinder for crack depth to wall thickness ratios, a/t , from 1/4 to 3/4 and aspect ratios, a/l , from 0 to 1/2. The DPFAD approach was used to derive closed-form J -integral expressions from limited elastic-plastic finite element solutions. Results are also presented in terms of the DPFAD curves as functions of a/t and a/l for the strain-hardening exponent of n = 8.6. Curves are given for the calibration constant h 1 as a function of a/t and a/l for ease of interpolation. Lastly, discussion is provided as to the applicability of the solutions and a possible interpolation scheme for obtaining h 1 values for n other than 8.6.