Numerical schemes for defining reference stress in components containing defects

摘要

In R6 and R5, the standards of integrity assessments of components containing defects established by the former Central Electricity Generating Board (CEGB) in the UK, the basic procedure in calculating the crack driving force parameters,J-integration and C*-integration is to define the reference stress, σ{sub}ref on the defective section. Three methods of directly defining the reference stress, σ{sub}ref [multiple steady-state creep analysis (MSCA) method, creep module-modifiediteration (CMMI) method and elastic module-modified iteration (EMMI) method], are suggested in this paper, differing from the common methods in which the limit loads of the components are first calculated and then the σ{sub}ref is convertibly determined. The basic conceptions and calculational steps of these methods are discussed and compared in the context, and the validity is demonstrated by several examples.