Fracture Toughness Evaluation of a Round Bar with a Circumferential Notch at Cryogenic Temperature

  • A. Nishimura
  • J. Yamamoto
  • A. Nyilas
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 44)


To characterize fracture toughness of thin plates or local positions in weld joints, a new fracture toughness test method is proposed. A small round bar with a circumferential notch is tensile-tested, and a load-displacement curve is recorded. J-integral is calculated continuously from a load start point to obtain a blunting line empirically. The critical J is determined at the fracture point on the blunting line. Some specimens show remarkable necking, and others fracture at or near the maximum load. Since necking generates a large plastic flow and cup & cone fracture, a flow diagram to evaluate the critical fracture toughness is assessed by adding some limitations. A comparison of results by this new method with ASTM E813-89 is performed, and both methods reveal nearly equivalent toughness value.


Fracture Toughness Compact Tension Notch Width ASTM Special Technical Publication Critical Fracture Toughness 
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Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • A. Nishimura
    • 1
  • J. Yamamoto
    • 1
  • A. Nyilas
    • 2
  1. 1.National Institute for Fusion ScienceToki, GifuJapan
  2. 2.Forschungszentrum KarlsruheITPKarlsruheGermany

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