Ductile Failure Analysis of Defective API X65 Pipes Based on Stress-Modified Fracture Strain Criterion

파괴변형률모델에 기초한 결함이 존재하는 API X65 배관의 연성파괴 해석

  • Published : 2006.09.01


A local failure criterion for the API X65 steel is applied to predict ductile failure of full-scale API X65 pipes with simulated corrosion and gouge defects under internal pressure. The local failure criterion is the stress-modified fracture strain for the API X65 steel as a function of the stress triaxiality (defined by the ratio of the hydrostatic stress to the effective stress). Based on detailed FE analyses with the proposed local failure criteria, burst pressures of defective pipes are estimated and compared with experimental data. The predicted burst pressures are in good agreement with experimental data. Noting that an assessment equation against the gouge defect is not yet available, parametric study is performed, from which a simple equation is proposed to predict burst pressure fur API X65 pipes with gouge defects.


Ductile fracture;API X65 steel;Stress triaxiality;Fracture strain


  1. Wilkoski, G., Stephens, D., Krishnaswamy, P., Leis, B. and Rudland, D., 2000, 'Progress in Development of Acceptance Criteria for Local Thinned Areas in Pipe and Piping Components,' Nuclear Engineering Design, Vol. 195, pp. 149-169
  2. Cosham, A. and Hopkins, P., 2004, 'The Effect of Dents in Pipelines-Guidance in the Pipeline Defect Assessment Manual,' International Journal of Pressure Vessels and Piping, Vol. 81, pp. 127-139
  3. American Petroleum Institute, 2000, Specification for Line Pipe
  4. Kanninnen, M.F., Zahoor, A., Wilkoski, G, Abousayed, I., Marschall, C., Broek, D., Sampath, S., Rhee, H., and Ahmad, J., 1982, 'Instability Predictions for Circumferentially Cracked Type-304 Stainless Pipes Under Dynamic Loading,' EPRI report NP-2347, Electric Power research Institute, Palo Alto, USA
  5. ASME, ASME Boiler and Pressure Vessel Code Section IX, 1992
  6. McClintock, F. A., 1968, 'A Criterion of Ductile Fracture by the Growth of Holes,' Journal of Applied Mechanics, Vol. 35, pp. 363-371
  7. Rice, J. R. and Tracey, D. M., 1969, 'On the Ductile Enlargement of Voids in Triaxial Stress Fields,' Journal of the Physics and Mechanics of Solids, Vol. 17, pp. 201-217
  8. Clausing, D. P., 1970, 'Effect of Plastic Strain State on Ductility and Toughness,' International Journal of Fracture Mechanics, Vol. 6, pp. 71-85
  9. Hancock, J. W. and Mackenzie, A. C., 1976, 'On the Mechanisms of Ductile Failure in High-Strength Steels Subject to Multi-Axial Stress States,' Journal of the Physics and Mechanics of Solids, Vol. 24, pp. 147-169
  10. Mackenzie, A., Hancock, J. and Brown, D., 1977, 'On the Influence of State of Stress on Ductile Failure Initiation in High Strength Steels,' Engineering Fracture Mechanics, Vol. 9, pp. 167-188
  11. Bao, Y., 2005, 'Dependence of Ductile Crack Formation in Tensile Test on Stress Triaxiality, Stress and Strain Ratios,' Engineering Fracture Mechanics, Vol. 72, pp. 505-522
  12. Alves, M. and Jones, N., 1999, 'Influence of Lydrostatic Stress on Failure of Axisymmetric Notched Specimens,' Journal of the Physics and Mechanics of Solids, Vol. 47, pp. 643-667
  13. Oh, C. K., Kim, Y. J, Park, J. M, Baek, J. H., and Kim, W. S, 2005, 'Development of Stress-Modified Fracture Strain Criterion for Ductile Fracture of API X65 Steel,' Trans. of the KSME (A), Vol. 29, No. 12, pp. 1621-1628
  14. Hibbitt, Karlson & Sorensen, Inc., 2005, ABAQUS Version 6.4 User's manual
  15. ANSUASME B31 G, 1991, Manual for Remaining Strength of Corroded Pipelines
  16. Kiefner, J. F. and Vieth, P.H., 1989, 'A Medified Criterion for Evaluating the Remaining Strength of Corroded Pipe,' American Gas Association, Catalog No. L51609, PR3-805
  17. Stephens, D. R., Leis, B. N., Kurre, J. D. and Rudland, D. L., 1999, 'Development of an Alternative Failure Criterion for Residual Strength of Corrosion Defects in Moderate-to-High Toughness Pipe,' Battelle report to PRC International Report, A. G. A. Gatalog Number L51794, January