Towards an analysis of leak-before-break assessments in the ductile tearing regime

Conference · Tue Dec 31 04:00:00 EST 1991

OSTI ID:10139672

Parfitt, V R

This paper presents the elastic-plastic fracture analysis of a typical semi-elliptical axial surface flaw growing to a thru-thickness flaw and assessing the leak-before break situation in a pressure vessel subject to pressure. The paper first discusses the semi-elliptical flaw J-integral solution and the thru-thickness flaw solution as modified herein. Then a review is presented of the three ductile tearing stability fracture analysis methods based on the fully plastic J-integral solution; (1) the crack driving force diagram, (2) the tearing modulus diagram, and (3) the failure assessment diagram. These methods are then used to determine the factors of safety to initiation of ductile tearing as the crack grows. Factors of safety based on either pressure alone or crack size alone are illustrated. An illustration is given of a leak-before-break solution discussing the semi-elliptical flaw growing to a thru-thickness flaw in the vessel. The paper concludes with a discussion of additional effort needed to better characterize leak-before-break solutions in the ductile tearing regime.

• Research Organization: Westinghouse Electric Corp., Monroeville, PA (United States)
• Sponsoring Organization: Department of Defense, Washington, DC (United States)
• OSTI ID: 10139672
• Report Number(s): WPAD-OPA-TI--1; CONF-910602--78; ON: DE94009419; NC: NONE
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200
COMPONENTS AND ACCESSORIES
CRACKS
DEFECTS
FAILURE MODE ANALYSIS
FRACTURES
LEAKS
PRESSURE VESSELS
REACTOR VESSELS