A study of complex defects failing by fatigue, ductile tearing and cleavage

Bezensek, B., Ren, Z. and Hancock, J.W. (2001) A study of complex defects failing by fatigue, ductile tearing and cleavage. In: Proceedings of the International Conference Nuclear Energy in Central Europe 2001, Portoroz,Slovakia, 10 - 13 September 2001, ISBN 961-6207-172

Abstract

Defect assessment procedures ensure the structural integrity of plant, which may contain complex defects. The present work addresses complex defects with re-entrant sectors, which develop from the interaction of two co-planar surface breaking defects in fatigue. Experimental studies show rapid fatigue growth and amplified crack driving forces in the re-entrant sector. This leads to the rapid evolution of the complex crack into a bounding semi-elliptical defect. Experiments involving ductile tearing of cracks with a re-entrant sector show that tearing initiates in the re-entrant sector and that the defect evolves into a bounding semi-elliptical defect. Cleavage failures of defects with re-entrant sectors indicate the re-characterisation procedure is only conservative after invoking constraint arguments. The study confirms the conservatism inherent in the re-characterisation rules of assessment procedures, such as BS 7910 [1] and ASME Section XI [2] for complex defects extending by fatigue or ductile earing. A potentially non-conservative situation exists for defects with re-entrant sectors failing by cleavage at small fractions of the limit load.

• Item Type: Conference Proceedings
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hancock, Professor John
• Authors: Bezensek, B., Ren, Z., and Hancock, J.W.
• Subjects: T Technology > TA Engineering (General). Civil engineering (General)
• College/School: College of Science and Engineering > School of Engineering
• ISBN: 961-6207-172