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

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

DOI QR Code

Investigation into Crack-Tip Constraint of Curved Wide-Plate using Q-Stress

Q-응력을 이용한 휜 광폭평판 균열부 구속상태 변화 평가

  • Lee, Hwee-Sueng (Dept. of Mechanical System Design Engineering, Seoul Nat’l Univ. of Science and Technology) ;
  • Huh, Nam-Su (Dept. of Mechanical System Design Engineering, Seoul Nat’l Univ. of Science and Technology) ;
  • Kim, Ki-Seok (Energy Infrastructure Research Group, POSCO) ;
  • Shim, Sang-Hoon (Energy Infrastructure Research Group, POSCO) ;
  • Cho, Woo-Yeon (Energy Infrastructure Research Group, POSCO)
  • 이휘승 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 허남수 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 김기석 (POSCO 에너지인프라연구그룹) ;
  • 심상훈 (POSCO 에너지인프라연구그룹) ;
  • 조우연 (POSCO 에너지인프라연구그룹)
  • Received : 2014.04.07
  • Accepted : 2014.07.10
  • Published : 2014.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

In the present paper, the effects of the thickness and width of a curved wide-plate, the crack length, and the strain hardening exponent on the crack-tip constraint of the curved wide-plate were investigated. To accomplish this, detailed three-dimensional elastic-plastic finite element (FE) analyses were performed considering various geometric and material variables. The material was characterized by the Ramberg-Osgood relationship, and the Q-stress was employed as a crack-tip constraint parameter. Based on the present FE results, the variations in the Q-stress of the curved wide-plate with the geometric variables and material properties were evaluated. This revealed that the effect of out-of-plane constraint conditions on the crack-tip constraint was closely related to the in-plane constraint conditions, and out-of-plane constraint conditions affected the crack-tip constraint more than in-plane constraint conditions.

본 논문에서는 휜 광폭평판의 두께와 폭, 균열길이 그리고 가공경화지수의 변화가 휜 광폭평판의 균열부 구속상태에 미치는 영향을 평가하였다. 이를 위해 5가지의 휜 광폭평판 두께, 3가지의 균열길이, 3가지의 휜 광폭평판 폭 그리고 3가지의 가공경화지수를 고려한 3차원 탄소성 유한요소해석을 수행하였다. Ramberg-Osgood 관계식을 만족하는 비선형 재료로 가정하였으며 균열부 구속상태를 정량화하기 위해서 Q-응력을 이용하였다. 3차원 유한요소해석 결과를 바탕으로 기하학적 형상 및 재료특성에 따른 휜 광폭평판의 Q-응력 변화를 평가하였다. 평가 결과 면외 구속조건에 의한 영향은 면내 구속조건과 밀접한 관계가 있었으며, 면외 구속조건이 면내 구속조건 보다 균열부 구속상태에 더 큰 영향을 미쳤다.

Keywords

References

  1. Kim, Y.J., Kim, J.S., Cho, S.M. and Kim, Y.J., 2004, "3-D Constraint Effects on J Testing and Crack-Tip Constraint in M(T), SE(B), SE(T) and C(T) Specimens: Numerical Study," Engineering Fracture Mechanics, Vol. 71, pp. 1203-1218. https://doi.org/10.1016/S0013-7944(03)00211-X
  2. 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
  3. Kirk, M.T. and Dodds, R.H.Jr., 1993, "J and CTOD Estimation Equations for Shallow Cracks in Single Edge Notch Bend Specimens," Journal of Testing and Evaluation, Vol. 21, No. 4, pp. 228-238. https://doi.org/10.1520/JTE11948J
  4. Huh, N.S., Kim, Y.J., Choi, J.B., Kim, Y.J. and Pyo, C.R., 2004, "Prediction of Failure Behavior for Nuclear Piping Using Curved Wide-Plate Test," ASME Journal of Pressure Vessel Technology, Vol. 126, pp. 419-425. https://doi.org/10.1115/1.1806447
  5. "ABAQUS/Standard User's Manual," Version 6.11-1, Dassault Systemes Corp., 2011.
  6. Hutchinson, J.W., 1968, "Singular Behavior of End of a Tensile Crack Tip in a Hardening Material," Journal of the Mechanics and Physics of Solids, Vol. 16, pp. 13-31. https://doi.org/10.1016/0022-5096(68)90014-8
  7. Rice, J.R. and Rosengren, G.F., 1968, "Plane Strain Deformation near a Crack Tip in a Power-Law Hardening Material," Journal of the Mechanics and Physics of Solids, Vol. 16, pp. 1-12. https://doi.org/10.1016/0022-5096(68)90013-6
  8. O'Dowd, N.P. and Shih, C.F., 1991, "Family of Crack Tip Fields Characterized by a Triaxiality Parameter-I, Structure of Fields," Journal of the Mechanics and Physics of Solids, Vol. 39, No. 8, pp. 989-1015. https://doi.org/10.1016/0022-5096(91)90049-T
  9. O'Dowd, N.P. and Shih, C.F., 1991, "Family of Crack Tip Fields Characterized by a Triaxiality Parameter-II, Fracture Applications," Journal of the Mechanics and Physics of Solids, Vol. 40, No. 5, pp. 939-963.
  10. Anderson, T.L., 2004, "Fracture Mechanics: Fundamentals and Applications," Third Edition, Chap. 3, CRC Press.