Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Methods to Evaluate Stress Triaxiality from the Side Necking Near the Crack Tip

균열선단 부근의 측면함몰로부터 응력삼축성의 결정 방법

  • 김동학 (한국원자력연구소 사용후핵연료기술개발부) ;
  • 강기주 (전남대학교 기계시스템공학부)
  • Published : 2004.07.01
Download PDF
⟨ Previous Next ⟩

Abstract

Kim et al. suggested an experimental method to determine the Q parameter in situ from the out-of-plane displacement and the in-plane strains on the surface of side necking near the crack tip. In this paper, the procedure to evaluate the stress triaxiality near a crack tip such as the Q parameter is to be polished in the details for simplicity and accuracy. That is, Q and hydrostatic stress are determined only from the out-of-plane displacement, but not using in-plane strain, which is hard to measure. And also, the plastic modulus is determined by an alternative way. Through three-dimensional finite element analyses for a standard CT specimen with 20% side-grooves, the validities of the new procedures are examined in comparison to the old ones. The effect of location where the displacements are measured to determine the stress triaxiality is explored.

Keywords

References

  1. ASTM EI737-96, 1998, 'Standard Test Method for J-Integral Characterization of Fracture Toughness,' Annual Book of ASTM Standards, Vol. 03.01
  2. Shih, C.F. and German, M.D, 1981, 'Requirements for a One Parameter Characterization of Crack Tip Fields by the HRR Singularity,' International Journal of Fracture, Vol. 17, pp. 27-43 https://doi.org/10.1007/BF00043119
  3. AI-Ani, A. M. and Hancock, J. W., 1991, 'J-Dominance of Short Cracks in Tension and Bending,' Journal of the Mechanics and Physics of Solids, Vol. 39, pp. 23-43 https://doi.org/10.1016/0022-5096(91)90029-N
  4. Du, Z.-Z. and Hancock, J. W., 1991, 'The Effect of Non-Singular Stresses on Crack-Tip Constraint,' Journal of the Mechanics and Physics of Solids, Vol. 39, pp. 555-567 https://doi.org/10.1016/0022-5096(91)90041-L
  5. Betegon, C. and Hancock, J. W., 1991, 'Two-Parameter Characterization of Elastic-Plastic Crack-Tip Fields,' Journal of applied mechanics, Vol.58, pp. 104-110 https://doi.org/10.1115/1.2897135
  6. Chao, Y.J., Yang, S., and Sutton, M.A, 1994, 'On the Fracture of Solids Characterized by One or Two Parameters: Theory and Practice,' Journal of the Mechanics and Physics of Solids, Vol.42, pp.629-647 https://doi.org/10.1016/0022-5096(94)90055-8
  7. Yang, S., Chao, Y. J. and Sutton, M. A., 1993, 'Higher order Asymptotic Crack Tip Fields in a Power-Law Hardening Material,' Engineering Fracture Mechanics Vol. 45, No. 1, pp1-20 https://doi.org/10.1016/0013-7944(93)90002-A
  8. O'Dowd, N.P and Shih, C.F., 1991, 'Family of Crack-Tip Fields Characterized by a Triaxiality Parameter- I. Structure of Field,' Journal of the Mechanics and Physics of Solids, Vol. 39, pp. 989-1015 https://doi.org/10.1016/0022-5096(91)90049-T
  9. O'Dowd, N.P and Shih, C.F., 1992, 'Family of Crack-Tip Fields Characterized by a Triaxiality Parameter- II. Fracture Application,' Journal of the Mechanics and Physics of Solids, Vol. 40, pp. 939-963 https://doi.org/10.1016/0022-5096(92)90057-9
  10. Kim, Dong-Hak, Lee, Jeong-Hyun, Kang, Ki-Ju, 2003, 'An Experimental Method for Measuring Q,' Transaction of the KSME, Vol.27, pp.1607-1613
  11. Nevalainen, M. and Dodds, Jr., R.H., 1995, 'Numerical Investigation of 3-D Constraint Effects on Brittle Fracture in SE(B) and C(T) Specimens,' International Journal of Fracture, Vol. 74, pp, 131-161 https://doi.org/10.1007/BF00036262
  12. Faleskog, J., 1995, 'Effects of Local Constraint Along Three-Dimensional Crack Fronts - A Numerical and Experimental Investigation,' Journal of the Mechanics and Physics of Solids, Vol. 43, pp. 447-493 https://doi.org/10.1016/0022-5096(94)00067-F
  13. Hancock, J.W., Reuter, W.G. and Parks, D.M., 1993, 'Constraint and toughness Parameterised by T,' Constraint Effects in Fracture, ASTM STP 1171, E.M. Hackett, K.H. Schwalbe and R.H. Dodds, Eds, American Society for Testing and Materials, Philadelphia, pp.21-40
  14. Brocks, W. and Schmitt, W., 1995, 'The Second Parameter in J-R curves: Constraint or Triaxiality,' 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, pp.209-231
  15. Henry, B.S. and Luxmoore, A.R., 1997, 'The Stress Triaxiality Constraint and The Q- Value as a Ductile Fracture Parameter,' Engineering Fracture Mechanics, Vol. 57, pp. 375-390 https://doi.org/10.1016/S0013-7944(97)00031-3
  16. Kang, Ki-Ju, Kim, Si-Young, Kim, Heon-Joong and Jeung Dae-Yeul, 2003, 'Effect of Loading Rate Upon Fracture Behavior of Ferritic Steel Under Large Scaled Yielding,' Nuclear Engineering and Design, Vol. 219, pp. 11-18 https://doi.org/10.1016/S0029-5493(02)00288-1