Title: Assessment of leak before break by modified average stress criterion

Authors: C.P. Goldin Priscilla; G. Karthikeyan

Addresses: Regional Centre, Anna University Tirunelveli Region, GCE Campus, Perumalpuram Post, Tirunelveli-627007, Tamilnadu, India ' Regional Centre, Anna University Tirunelveli Region, GCE Campus, Perumalpuram Post, Tirunelveli-627007, Tamilnadu, India

Abstract: Design of pressure vessels and piping without considering presence of pre-existing or postulated crack will be vulnerable for time, human lives and other values. The successfulness of fracture mechanics lies in its theoretical frame work supported by experimental evidences. Leak before break is a fail-safe design concept for application in pressure vessels and piping of process plants. Most of the earlier researches are based on plane strain fracture toughness KIc and JIc. Two of such concepts namely Irwin's and Kobayashi's have been applied for a set of data taken from literature and shown that they are not complied with. A simple correlation between failure stress and SIF at failure based on average stress criterion is proposed for fracture analysis. A set of literature test data comprising of leak and break cases has been studied and the criterion is demonstrated.

Keywords: leak assessment; leak before break; failsafe design; fracture mechanics; average stress criterion; pressure vessels; piping.

DOI: 10.1504/IJCAET.2015.066169

International Journal of Computer Aided Engineering and Technology, 2015 Vol.7 No.1, pp.29 - 37

Published online: 17 Nov 2014 *

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