Practical Failure Analysis

, Volume 3, Issue 4, pp 23–27 | Cite as

Oak Ridge National Laboratory (ORNL) spiral notch torsion test (SNTT) system

  • Jy-An John Wang
Features Testing


he Oak Ridge National Laboratory (ORNL) spiral notch torsion test (SNTT) system measures the intrinsic fracture toughness (K Ic) of structural materials, overcomes many of the limitations inherent in traditional techniques, and introduces new possibilities for standardizing fracture toughness testing. The system is uniquely suited to test a wide variety of materials, such as metals and alloys, ceramics, composites, polymers, carbon foam, and concrete. The SNTT system operates by applying pure torsion to cylindrical secimens machined with a notch line that spirals around the specimen at a 45° pitch (Fig. 1). Results are obtained with the aid of TOR3D-KIC, a three-dimensional finite-element computer code developed at ORNL, which may be obtained by contacting the author.


Fracture Toughness Failure Analysis Fracture Toughness Test Carbon Foam Nuclear Power Industry 
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  1. 1.
    J.A. Wang, K.C. Liu, and D.E. McCabe: “An Innovative Technique for Measuring Fracture Toughness of Metallic and Ceramic Materials,”Fatigue and Fracture Mechanics, 33, STP 1417, ASTM, West Conshohocken, PA, 2003, pp. 757–70.Google Scholar

Selected References

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    J.A. Wang: “TOR3D-KIC: A 3-D Finite Element Analysis Code for the Determination of Fracture Toughness,K Ic, for Spiral Notch Torsion Test,” Oak Ridge National Laboratory, Oak Ridge, TN, internal report for technical transfer, 2001.Google Scholar
  3. •.
    J.A. Wang and K.C. Liu: “A New Approach to Evaluate Fracture Toughness of Structural Materials,”Proceedings of ASME Pressure Vessel and Piping, American Society of Mechanical Engineers, New York, NY, 2003.Google Scholar
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    J.A. Wang and K.C. Liu: “Fracture Toughness Determination Using Spiral-Grooved Cylindrical Specimen and Pure Torsional Loading,” U.S. Patent 6,588,283, 8 July 2003.Google Scholar
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    •J.A. Wang, K.C. Liu, and G.A. Joshi: “Using Torsion Bar Testing to Determine Fracture Toughness of Ceramic Materials,” CMDA-29077,Proceedings of ETCE 2002 Conference on Composite Materials Design and Analysis, American Society of Mechanical Engineers, New York, NY, 2002.Google Scholar
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    J.A. Wang, K.C. Liu, D.E. McCabe, and S.A. David: “Using Torsion Bar Testing to Determine Fracture Toughness,K Ic,”J. Fatigue Fract. Eng. Mater. Struct., 2001,23, pp. 45–56.Google Scholar
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    •J.A. Wang, R.C. Singleterry, Jr., R.J. Ellis, and H.T. Hunter: “Radiation Effects on Spacecraft Structural Materials,”Proceedings of International Conference on Advanced Nuclear Power Plants, American Nuclear Society, La Grange Park, IL, 2002.Google Scholar

Copyright information

© ASM International - The Materials Information Society 2003

Authors and Affiliations

  • Jy-An John Wang
    • 1
  1. 1.Nuclear Science and Technology DivisionOak Ridge National LaboratoryOak Ridge

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