Comparison of crack initiation life estimation procedures under creep-fatigue conditions

✍ Scribed by M.P. O’Donnell

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 667 KB
• Volume: 235
• Category: Article
• ISSN: 0029-5493
• DOI: 10.1016/j.nucengdes.2005.05.017

✦ Synopsis

This paper describes the application of "high temperature structural integrity assessment procedures" developed in the UK and Japan to creep-fatigue crack initiation in welded Type 316 features tests. The components were subjected to both fatigue and creep-fatigue loading at 630 • C. The loadings are representative of those on the upper seal gimbal joint in an advanced gas cooled reactor (AGR), except that the tests were isothermal and the imposed dwell times were reduced. It is demonstrated that application of the procedures gives accurate predictions of the observed crack initiation in the weldment, based on two different advanced inelastic constitutive models (BE and CRIEPI models) and best estimate materials data. Application of simplified assessment methods based on elastic analysis is shown to be conservative. Where appropriate, contrasts between the UK and the Japanese assessment procedures and inelastic modelling techniques have been highlighted.