ISSN: 1546-962X
CODEN: JAIOAD
Published Online: 5 January 2004
Page Count: 19

Constraint Correction of Fracture Toughness CTOD for Fracture Performance Evaluation of Structural Components

Minami, F
Associate Professor, Graduate School of Engineering, Osaka University, Suita, Osaka,

Arimochi, K
General Manager, Plate & Structural Steel Project Promoting Department, Sumitomo Metal Industries, LTD., Hyogo,

(Received 31 August 2001; accepted 9 May 2002)

Abstract

A correction of CTOD for constraint loss in large-scale yielding conditions is made on the basis of the Weibull stress fracture criterion that eliminates an excessive conservatism in the conventional fracture assessment and material fracture toughness requirement. A CTOD ratio β = δ_3P / δ_WP (<1) is proposed, where δ_WP is the CTOD of a wide plate component and δ_3P is an equivalent CTOD of the fracture toughness specimen at which the toughness specimen gives a compatible Weibull stress with the wide plate. The CTOD ratio β is decreased to a large extent after full yielding of the wide plate component, which is more significant for a high yield ratio YR and a deep surface crack in the wide plate. The Weibull modulus m exerts a marginal influence on β. A case study is presented on the application of the CTOD ratio β to the fracture performance assessment of full-scale column-to-beam connections subjected to cyclic and dynamic loading.

Keywords:
brittle fracture, constraint effect, transferability analysis, fracture toughness, fracture performance, equivalent CTOD, Weibull stress criterion, structural steels

Paper ID: JAI10615
DOI: 10.1520/JAI10615
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