Effect of Plastic Constraint on Brittle Fracture in Steel: Evaluation Using a Toughness Scaling Model
Publication: Journal of Structural Engineering
Volume 138, Issue 6
Abstract
Over the past two decades, plastic constraint effects have been an issue of concern in both fracture mechanics and structural integrity research, and several methods have been proposed for considering loss of plastic constraint. This paper shows the ability of a simplified model to predict brittle fracture under low plastic constraint conditions. Fracture toughness tests are performed on single-edge notched bend (SENB) steel specimens with deep and shallow notches, as well as on double-edge notched tension and center-notched tension (CNT) specimens. When compared with SENB specimens with a deep notch, the CNT specimens show high fracture toughness as a result of the loss of plastic constraint at the crack tip. Here, the Weibull stress approach and a toughness scaling model (TSM) are used to consider the effects of the loss of plastic constraint on the fracture toughness of the specimens. The corrected fracture toughness values evaluated by the TSM are found to be close to the toughness values observed in the tests and to the values predicted by the Weibull stress approach. This paper also briefly discusses the effect of ductile crack growth on brittle fracture.
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Acknowledgments
This research was supported in part by the Japan Iron and Steel Federation and the Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research. We would like to thank Prof. J. A. Packer (University of Toronto) for his comments on this paper.
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Information & Authors
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Published In
Journal of Structural Engineering
Volume 138 • Issue 6 • June 2012
Pages: 744 - 752
Copyright
© 2012. American Society of Civil Engineers.
History
Received: Feb 22, 2011
Accepted: Sep 23, 2011
Published online: Sep 26, 2011
Published in print: Jun 1, 2012
Published ahead of production: Jun 15, 2012
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