Error estimation of numerical stress intensity factors for semi-elliptical cracks

Abstract

A set of polynomial influence functions is derived for some typical cracks in nuclear reactor components. The crack geometries considered are circumferential and axial partelliptical cracks on the inner surface of a cylindrical pressure vessel. Based on the boundary-element method, the influence functions are calculated for a wide range of crack configuration parameters and at numerous kinds of polynomial crack-face loading. Based on the averaged error estimation technique, the efficiency of numerical analyses and the accuracy related solutions are shown to be rather high. The results on stress intensity factors are fitted by parametric formulae making use of the least-square procedure. The derived solutions are employed for crack analyses at pressurized thermal shock loading of a reactor pressure vessel, as well as for the verification of existing regulatory guides

Characterization of the computational accuracy in surface crack problems

“…Computations have been carried out for the value of Poisson's ratio "0)3. For the purposes of the present study and for the sake of compatibility with the results, the following problems were additionally considered: (1) Axial crack in a cylinder with the boundary conditions (5) and geometries defined by (14) and (15). Poisson's ratio, however, was set to "0.…”