Development of a framework to account for the test specimen size effects on fracture toughness of irradiated materials by considering the out-of-plane constraint

2014 Fiscal Year Final Research Report

• Project/Area Number: 24561038
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Nuclear engineering
• Research Institution: University of Fukui
• Principal Investigator: MESHII Toshiyuki 福井大学, 工学(系)研究科(研究院), 教授 (10313727)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 破壊靱性値 / 延性―脆性遷移温度域 / 照射脆化 / 試験片の寸法効果 / き裂先端の拘束 / T-stress / 有限要素解析 / 破壊評価基準

Outline of Final Research Achievements

The object of this work was to develop a framework to account for the test specimen size effects on fracture toughness Jc of irradiated materials. Our perspective was that a mechanical driving factor such as the stress distribution difference can explain the size effects in Jc, at least for specimens specified in ASTM E1921 or equivalent. The results obtained were as follows: 1) Demonstrated that the cause of the size effects in Jc was due to the inability of J to characterize the crack-tip stress fields accurately. 2) Proposed a method to predict the lower bound Jc for large thickness specimens. 3) Proposed a framework to convert Jc between different specimen types and thicknesses by using finite element analysis and the modified Ritchie-Knott-Rice failure criterion. By utilizing these results, it is now possible to convert the Jc data accumulated in Japan for various specimen types and thicknesses to the Jc that is expected for a 1 inch CT specimen, recommended by IAEA.

Free Research Field

破壊力学