Advertisement

Modelling of Creep Crack Growth

  • G. A. Webster

Abstract

Models for describing creep crack growth in terms of linear and non-linear fracture mechanics concepts are presented. When an elastic stress field is preserved at a crack tip it is shown that crack growth rate can be correlated by the stress intensity factor K and when a creep stress distribution is attained by the creep fracture parameter C*. However since creep strains of about the elastic strains only are required for stress redistribution, it is demonstrated that C* is likely to characterize crack growth in brittle as well as ductile materials unless creep ductilities as small as the elastic strains are measured. A procedure for including ligament damage is included for making residual life estimates.

Keywords

Stress Intensity Factor Crack Growth Rate Creep Strain Failure Strain Crack Propagation Rate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Ellison, E.G. and Harper, M.P., Creep behaviour of components containing cracks - a critical review. J. Strain Anal, 1978, 13, 35–51.CrossRefGoogle Scholar
  2. 2.
    Webster, G.A., Crack growth at high temperature. In Engineering approaches to high temperature design, eds. B. Wilshire and D.R.J. Owen, Pineridge Press, Swansea, 1983, pp 1–56.Google Scholar
  3. 3.
    Riedel, H. and Rice, J.R., Tensile cracks in creeping solids. In Fracture Mechanics, ASTM STP 700, 1980, pp 112–130.CrossRefGoogle Scholar
  4. 4.
    Hutchinson, J.W., Singular behaviour at the end of a tensile crack in a hardening material. J. of Mechanics and Physics of Solids, 1968, 16, 13–31.CrossRefGoogle Scholar
  5. 5.
    Nikbin, K.M., Smith, D.J. and Webster, G.A., Influence of creep ductility and state of stress on creep crack growth. In Advances in Life Prediction Methods at Elevated Temperatures, eds., D.A. Woodford and J.R. Whitehead, ASME, New York, 1983, pp 249–258.Google Scholar
  6. 6.
    Nikbin, K.M., Smith, D.J. and Webster, G.A., Prediction of creep crack growth from uniaxial creep data, Proc. Roy. Soc., 1984, A396, 183–197.Google Scholar
  7. 7.
    Nikbin, K.M., Smith, D.J. and Webster, G.A., An engineering approach to the prediction of creep crack growth, J. Eng. Mat. and Tech., 1986, 108, 186–191.CrossRefGoogle Scholar
  8. 8.
    Dimopulos, V., Failure analysis of components at high temperatures, Ph.D. thesis, University of London, 1988.Google Scholar
  9. 9.
    Haigh, J.R. and Richards, C.E., Yield loads and compliance functions of fracture mechanics specimens, CEGB, CERL memo, RD/L/M/461, 1974.Google Scholar
  10. 10.
    Nikbin, K.M., Webster, G.A. and Turner, O.E., A comparison of methods of correlating creep crack growth. In Fracture, ed., D.M.R. Taplin, Waterloo, Canada, 1977, 2, 627–634.Google Scholar
  11. 11.
    Webster, G.A., Modelling of creep crack growth in virgin and service exposed material. In High Temperature Crack Growth, I. Mech. E., London, 1987, 1–7.Google Scholar
  12. 12.
    Nishida, K. and Webster, G.A., Prediction of failure by creep crack growth and net section damage. In Materials and Engineering Design, Inst, of Metals, London, 1988, E1-E3.Google Scholar
  13. 13.
    Goodall, I.W., Leckie, F.A., Ponter, A.R.S., Townley, C.H.A., The development of high temperature design methods based on reference stresses and bounding theorems, J.Eng.Mat. and Tech., ASME, 1979, 101, 1979, 349–355.CrossRefGoogle Scholar
  14. 14.
    Coleman, M.C., Price, A.T. and Williams, J.A. Crack growth in pressure vessels in creep conditions. In Fracture, ed., D.M.R. Taplin, Waterloo, Canada, 1977, 2, 649–662.Google Scholar
  15. 15.
    Coleman, M.C. Creep crack growth in a CrMoV throttle valve pressure vessel. In Advances in Fracture, ed. D. Francois, Pergamon, Oxford, 1980, 3, 1235–1244.Google Scholar

Copyright information

© Elsevier Science Publishers Ltd 1989

Authors and Affiliations

  • G. A. Webster
    • 1
  1. 1.Dept. of Mechanical EngineeringImperial CollegeLondonUK

Personalised recommendations