Structure life prediction at high temperature: present and future capabiIities

Abstract

AbstractThe life prediction techniques for high temperature conditions include several aspects which are considered successi vely in this article. Firstly we look at the crack initiation criteria themselves, defined for the isolated volume element (the tension- compression specimen for example), including parametric relationships and continuous damage approaches. Next , we examine the calculation oflocal stress and strain fields in the structure and their evolution under cyclic plasti city , which poses several difficult problems to obtain stabilized cyclic solutions. Finally , we turn our attention to the use of crack initiation criteria or damage rul es from the result ofthe cyclic inelastic analysis and the prediction ofcrack growth in the structure.Different levels are considered for the predictive tools: the classical approach, future methods presently under development and intermediate rules, which are already in use. Several examples are given on materials and components used either in the nuclear ...