Creep analysis and life assessment using cross-weld specimens

Abstract

Cross-weld creep specimens have been widely studied in order to aid in the understanding of the creep behaviour of real, welded structures. The studies published to date have been of an analytical, numerical, or experimental nature. This review describes the analytical methods used to predict the creep behaviour of cross-weld specimens with simple geometries. For both simple and more complex geometries, use of the finite element (FE) method to obtain stationary state stresses and strains has been made, and the solutions contrasted with those of the simpler analytical methods. Use of the creep continuum damage constitutive equations in FE analyses to predict the failure times of, and rupture positions in, cross-weld specimens has been described. The effect of various features, defined by the analysis methods, is highlighted. Problems with the experimental validation of these effects are considered and selected experimental data from creep tests on cross-weld creep specimens for various materials and geometries are presented. These are interpreted using the results from the analytical and numerical methods described. The potentials and limitations of the methods presented are discussed.