Table of Contents Author Guidelines Submit a Manuscript
Advances in Materials Science and Engineering
Volume 2014, Article ID 269137, 8 pages
Research Article

Application of -Stress to Predict the Lower Bound Fracture Toughness for Increasing the Test Specimen Thickness in the Transition Temperature Region

1Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui-shi, Fukui 910-8507, Japan
2Faculty of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui-shi, Fukui 910-8507, Japan

Received 28 December 2013; Accepted 23 January 2014; Published 13 March 2014

Academic Editor: Filippo Berto

Copyright © 2014 Kai Lu and Toshiyuki Meshii. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This work was motivated by the fact that although fracture toughness of a material in the ductile-to-brittle transition temperature region exhibits the test specimen thickness (TST) effect on , frequently described as , experiences a contradiction that is deduced from this empirical formulation; that is, = 0 for large TST. On the other hand, our previous works have showed that the TST effect on could be explained as a difference in the out-of-plane constraint and correlated with the out-of-plane -stress. Thus, in this work, the TST effect on for the decommissioned Shoreham reactor vessel steel A533B was demonstrated from the standpoint of out-of-plane constraint. The results validated that was effective for describing the decreasing tendency. Because the Shoreham data included a lower bound for increasing TST, a new finding was made that successfully predicted the lower bound of with increasing TST. This lower bound prediction with conquered the contradiction that the empirical predicts = 0 for large TST.