The Severity Near the Notch Root of Notched Bars

  • H. Hyakutake
  • T. Hagio


Finite element analysis near the notch root of notched bars under tension was studied for a wide range of notch geometries. The analysis shows that the yielded zone size near the notch root is determined by both the maximum elastic stress and notch root radius. Therefore, we can express the severity near the notch root by both of the maximum elastic stress and notch root radius. In addition to the analysis, the concept of severity is subjected to further experimental scrutinization in the present paper. An experimental program is presented which examines the effect of notch root radius on the yielded zone size for the notched specimens under static tension. This is accomplished by obtaining experimental data on the notched plates and the circumferentially notched bars of polycarbonate. From the experimental results, we confirm the validity of the concept of severity for predicting the fracture strength of notched bars.


Fracture Strength Fracture Criterion Notch Root Glassy Polymer Notch Depth 
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  1. 1.
    Williams, J.G., Fracture Mechanics of Polymers, Ellis Horwood, Chichester, 1984.Google Scholar
  2. 2.
    Takano, M. and Nielsen L.E., The notch sensitivity of polymeric materials. J. Appl. Polym. Sci., 1976, 20, pp. 2193–2207.CrossRefGoogle Scholar
  3. 3.
    Prabhakaran, R., Nair, E.M.S., and P. K., Sinha, Notch sensitivity of polymers. J. Appl. Polym. Sci., 1978, 22, pp. 3011–3020.CrossRefGoogle Scholar
  4. 4.
    Mills, N.J., The mechanism of brittle fracture in notched impact tests on polycarbonate. J. Mater. Sci., 1976, 11, pp. 363–375.CrossRefGoogle Scholar
  5. 5.
    Narisawa, I., Ishikawa, M. and Ogawa, H., Notch brittleness of ductile glassy polymers under plane strain. J. Mater. Sci., 1980, 15, pp. 2059–2065.CrossRefGoogle Scholar
  6. 6.
    Kitagawa, M., Plastic deformation and fracture of notched specimens due to bending in glassy polymers. J_;_ Mater. Sci., 1982, 17, pp. 2514–2524.CrossRefGoogle Scholar
  7. 7.
    Nuismer, R.J. and Whitney, J.M., Uniaxial failure of composite laminates containing stress concentrations. In Fracture Mechanics of Composites, ASTM STP 593, ed. S.P. Sendekyi, American Society for Testing Materials, Philadelphia, 1975, pp. 117–142.Google Scholar
  8. 8.
    Nisitani, H. and Hyakutake, H., Condition for determining the static yield and fracture of a polycarbonate plate specimen with notches. En. Fract. Mech., 1985, 22, pp. 359–368.Google Scholar
  9. 9.
    Hyakutake, H. and Nisitani, H., Conditions for ductile and brittle fracture in notched polycarbonate bars. JSME Inter. J., 1987, 30, pp. 29–36.Google Scholar
  10. 10.
    Fraser, R.A.W., and Ward, I.M., The impact fracture behaviour of notched specimens of polycarbonate. J. Mater. Sci., 1977, 12, pp. 459–468.Google Scholar
  11. 11.
    Pitman, G.L., Ward, I.M. and Duckett, R.A., The effects of thermal pre-treatment and molecular weight on the impact behaviour of polycarbonate. J. Mater. Sci., 1978, 13, pp. 2092–2104.CrossRefGoogle Scholar
  12. 12.
    Parvin, M. and Williams, J.G., Ductile-brittle fracture transitions in polycarbonate. Int. J. Fract., 1975, 11, pp. 963–972.Google Scholar
  13. 13.
    Brown, H.R., A model for brittle-ductile transitions in polymers. J. Mater. Sci., 1982, 17, pp. 469–476.Google Scholar
  14. 14.
    Hyakutake, H., Nisitani, H. and Hagio, T., Fracture criterion of notched plates of FRP. JSME Inter J., 1989, 32, pp. 300–306.Google Scholar
  15. 15.
    Hyakutake, H., Hagio, T., and Nisitani, H., Fracture of FRP plates containing notches or a circular hole under tension. The 1989 ASME Pressure Vessels and Piping Conference, Vol. 167, American Society of Mechanical Engineers, New York, 1989, pp. l41–146.Google Scholar

Copyright information

© Elsevier Science Publishers Ltd 1990

Authors and Affiliations

  • H. Hyakutake
    • 1
  • T. Hagio
    • 1
  1. 1.Department of Mechanical EngineeringFukuoka UniversityFukuokaJapan

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