A Modified Two-Parameter Solution for Crack-Tip Field in Bending Dominated Specimens

  • Jang Seok-Ki (Dept. of Marine Engineering, Mokpo Maritime University) ;
  • Zhu Xian Kui (Battelle, Pipeline Technology Center Columbus)
  • Published : 2006.05.01

Abstract

It is well known that the two-parameter $J-A_2$ solution can well characterize the crack-tip fields and quantify the crack-tip constraint for different flawed geometries in variety of loading conditions. However, this solution fails to do so for bending dominated specimens or geometries at large deformation because of the influence of significant global bending stress on the crack-tip field. To solve this issue, a modified $J-A_2$ solution is developed in this paper by introducing an additional term to address the global bending influence. Using the $J_2$ flow theory of plasticity and within the small-strain framework detailed finite element analyses are carried out for the single edge notched bend (SENB) specimen with a deep crack in A533B steel at different deformation levels ranging from small-scale Yielding to large-scale Yielding conditions. The numerical results of the crack-tip stress field are then compared with those determined from the $J-A_2$ solution and from the modified $J-A_2$ solution at the same level of applied loading Results indicate that the modified $J-A_2$ solution largely improves the $J-A_2$ solution, and match very well with the numerical results in the region of interest at all deformation levels. Therefore, the proposed solution can effectively describe the crack-tip field and the constraint for bending dominated specimens or geometries.

Keywords

References

  1. Rice, J. R., A path independent integral and the approximate analysis of strain concentration by notches and cracks, Journal of Applied Mechanics, 35: 379-386, 1968 https://doi.org/10.1115/1.3601206
  2. Hutchinson, J. W., Singular behavior at the end of a tensile crack in a hardening material, Journal of the Mechanics of Physics and Solids, 16: 13-31, 1968 https://doi.org/10.1016/0022-5096(68)90014-8
  3. Rice, J.R. and Rosengren, G.F., Plane strain deformation near a crack tip in a power law hardening material, Journal of the Mechanics of Physics and Solids, 16: 1-12, 1968 https://doi.org/10.1016/0022-5096(68)90013-6
  4. Jang, S.K. and Zhu, X.K., Twoparameter characterization for the resistance curves of ductile crack growth, Journal of the Korean Society of Marine Engineers, 23: 70-85, 1999
  5. Zhu, X. K. and Jang, S. K., J-R curves corrected by load independent constraint parameter in ductile crack growth, Engineering Fracture Mechanics, 68: 285-301, 2001 https://doi.org/10.1016/S0013-7944(00)00100-4
  6. Zhu, X.K. and Chao, Y.J., Constraint effects on crack-tip fields in elasticperfectly plastic materials, Journal of the Mechanics and Physics of Solids, 49: 363-399, 2001 https://doi.org/10.1016/S0022-5096(00)00030-2
  7. Betegon, C. and Hancock, J.W., Two parameter characterization of elasticplastic crack-tip fields, Journal of Applied Mechanics, 58: 104-110, 1991 https://doi.org/10.1115/1.2897135
  8. Al-Ani, A. M. and Hancock, S. W., J-dominance of short cracks in tension and bending, Journal of the Mechanics of Physics and Solids, 39: 23-43, 1991 https://doi.org/10.1016/0022-5096(91)90029-N
  9. O'Dowd, N. P. and Shih, C.F., Family of crack-tip fields characterized by a triaxiality parameter I. structure of fields, Journal of the Mechanics of Physics and Solids, 39: 989-1015, 1991 https://doi.org/10.1016/0022-5096(91)90049-T
  10. O'Dowd, N.P. and Shih, C.F., Family of crack-tip fields characterized by a triaxiality parameter II. fracture applications, Journal of the Mechanics of Physics and Solids, 40: 939-963, 1992 https://doi.org/10.1016/0022-5096(92)90057-9
  11. Yang, S., Chao, Y. J. and Sutton, M. A., Higher-order asymptotic fields in a power-law hardening material, Engineering Fracture Mechanics, 45: 1-20, 1993 https://doi.org/10.1016/0013-7944(93)90002-A
  12. Chao, Y. J., Yang, S. and Sutton, M. A., On the fracture of solids characterized by one or two parameters: theory and practice, Journal of the Mechanics of Physics and Solids, 42: 629-647, 1994 https://doi.org/10.1016/0022-5096(94)90055-8
  13. Chao, Y. J. and Zhu, X. K., J-A2 characterization of crack-tip fields: extent of J-A2 dominance and size requirements, International Journal of Fracture, 89: 285-307, 1998 https://doi.org/10.1023/A:1007487911376
  14. Shih, C. F. and German, M. D., Requirements for a one parameter characterization of crack tip fields by HRR singularity, International Journal of Fracture, 17: 27-43, 1981
  15. Parks, D. M.,, Advances in characterization of elastic-plastic crack-tip fields, Fracture and Fatigue, A.S. Argon, Ed., Spring-Verlag, New York, 59-98, 1992
  16. Wang, Y. Y. and Parks, D. M.,, Limit of J-T characterization of elastic- Plastic Crack-Tip Fields, Constraint Effects in Fracture Theory and Applications: Second Volume, ASTM STP 1244, Mark Kirk and Ad Bakker, Eds., American Society for Testing and Materials, Philadelphia, 43-67, 1995
  17. Wei, Y. and Wang, T., Characterization of elastic-plastic fields near stationary crack tip and fracture criterion, Engineering Fracture Mechanics, 51: 541-553, 1995
  18. Karstensen, A.D., Nekkal, A. and Hancock, J.W., Constraint estimation for edge cracked bending bars, IUTAM Symposium on Nonlinear Analysis of Fracture(J.R. Willis ed.), Kluwer Academic Publishers, Netherlands, 23-32, 1997
  19. Lam, P. S, Chao, Y. J., Zhu, X. K., Kim, Y., and Sindelar, R. L., Determination of constraint-modified J-Rcurves for carbon steel storage tanks, Journal of Pressure Vessel Technology, 123: 111-222, 2003
  20. Chao, Y.J. and Zhang, L., Tables of plane strain crack tip fields: HRR and higher order terms, Me-Report, 97-1, Department of Mechanical Engineering, University of South Carolina, 1997