Fracture Toughness Evaluation for Spent Nuclear Fuel Clad Systems Using Spiral Notch Torsion Fracture Toughness Test

Code Case N-670 “Use of Ductile Cast Iron Conforming to ASTM A874/A 874M-98 or JIS G5504-1992 for Transport Containments, Section III, Division 3” which permits use of ductile cast iron for transport containments of spent nuclear fuel was revised to the Code Case N-670-1, “Use of Ductile Cast Iron Conforming to ASTM A874/A 874M-98 or JIS G5504-2005 for Transport and Storage Containments, Section III, Division 3”. Items revised were as follows: (a) Scope was expanded to use for transport and storage, and changed to conform year edition of JIS G5504, (b) The elongation requirement was deleted form the code case to reflect the change of year edition of JIS G5504, (c) Temperature condition of −40 °C was clearly provided for fracture toughness test, (d) Design fatigue curve was re-established, (e) External pressure chart was re-established. Technical basis of the revised code case are described in this paper.

Download Full-text

Constraint Effect—How to Link Between Structural Integrity Assessment and Fracture Toughness Evaluation

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.2829054 ◽

1997 ◽

Vol 119 (2) ◽

pp. 125-133

Author(s):

M. Toyoda

Keyword(s):

Fracture Toughness ◽

Structural Integrity ◽

Fracture Toughness Test ◽

Stress Strain ◽

Integrity Assessment ◽

Strain Behavior ◽

Plastic Constraint ◽

Toughness Evaluation ◽

The Difference ◽

Fracture Toughness Evaluation

The difference in the degree of plastic constraint in the vicinity of a pre-existing crack brings about difficulty in the evaluation of fracture performance of weldments when using fracture toughness obtained by conventional fracture toughness test results. The constraint controlling factors can be divided into two main areas, geometrical and material factors. The effect of both factors on the stress/strain behavior in the vicinity of a crack tip is discussed systematically based on previous research and numerical analyses. It is clarified that the common fracture parameters such as J and CTOD do not always represent material constants because of the change of stress/strain behavior as a result of the difference in plastic constraint. The possibility of evaluation based on the local approach is discussed in order to link between structural integrity assessment and fracture toughness evaluation.

Download Full-text

Spiral Notch Torsion Test Use for Determining Fracture Toughness of Structural Materials

Volume 6: Materials and Fabrication, Parts A and B ◽

10.1115/pvp2012-78782 ◽

2012 ◽

Author(s):

Jy-An John Wang ◽

Fei Ren ◽

Ting Tan

Keyword(s):

Fracture Toughness ◽

Three Dimensional ◽

Torsion Test ◽

Computer Code ◽

Structural Materials ◽

Fracture Toughness Test ◽

Materials Used ◽

Torsion Fracture ◽

Three Dimensional Finite Element ◽

Spiral Notch

Spiral Notch Torsion Fracture Toughness Test (SNTT) was developed recently to measure the intrinsic fracture toughness (KIC) of structural materials. The SNTT system operates by applying pure torsion to uniform cylindrical specimens with a notch line that spirals around the specimen at a 45° pitch. The KIC values are obtained with the aid of a three-dimensional finite-element computer code, TOR3D-KIC. The SNTT method is uniquely suitable for testing a wide variety of materials used extensively in pressure vessel and piping structural components and weldments, including others such as ceramics, their composites, graphite, concrete, and polymeric composites. The SNTT test results for some of these structural materials are demonstrated in this paper.

Download Full-text