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

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

DOI QR Code

On Relevant Ramberg-Osgood Fit to Engineering Non-Linear Fracture Mechanics Analysis

정확한 비선형 파괴역학 해석을 위한 Ramberg-Osgood 상수 결정법

  • Published : 2003.09.01
Download PDF
⟨ Previous Next ⟩

Abstract

This paper proposes a robust method for the Ramberg-Osgood(R-O)fit to accurately estimate elastic-plastic J from engineering fracture mechanics analysis based on deformation plasticity. The proposal is based on engineering stress-strain data to determine the R-O parameters, instead of true stress-strain data. Moreover, for practical applications, the method is given not only for the case when full stress-strain data are available but also for the case when only yield and tensile strengths are available. Reliability of the proposed method for the R-O fit is validated against detailed 3-D Finite Element (FE) analyses for circumferential through-wall cracked pipes under global bending using five different materials, three stainless steels and two ferritic steels. Taking the FE J results based on incremental plasticity using actual stress-strain data as reference, the FE J results based on deformation plasticity using various R-O fits are compared with reference J values. Comparisons show that the proposed R-O fit provides more accurate J values for all cases, compared to existing methods for the R-O fit. Advantages of the proposed R-O fit in practical applications are discussed, together with its accuracy.

Keywords

References

  1. Kumar, V. and German, M.D., 1988, 'Elastic-Plastic Fracture Analysis of Through- Wall and Surface Flaws in Cylinders,' EPRI Report, NP-5596
  2. Huh, N.S., Park, Y.J., Kim, Y.J. and Kim, Y.J., 2003, 'New Engineering J and COD Estimation Methods for Axial Through-Wall Cracked Pipes,' Transactions of the KSME(A), Vol. 27, No.2, pp. 239-246 https://doi.org/10.3795/KSME-A.2003.27.2.239
  3. Rahman, S., Brust, F., Ghadiali, N. and Wilkowski, G., 1998, 'Crack-Opening-Area Analyses for Circumferential Through-Wall Cracks in Pipes-Part I: Analytical Models,' International Journal of Pressure Vessels and Piping, Vol. 75, pp. 357-373 https://doi.org/10.1016/S0308-0161(97)00081-1
  4. Ramberg, W. and Osgood, W.R., 1943, 'Description of Stress-Strain Curves by Three Parameters,' NACA-TN-902, NACA
  5. Rahman, S., Brust, F., Ghadiali, N. and Wilkowski, G., 1998, 'Crack-Opening-Area Analyses for Circumferential Through-Wall Cracks in Pipes-Part II: Model Validations,' International Journal of Pressure Vessels and Piping, Vol. 75, pp. 375-396 https://doi.org/10.1016/S0308-0161(97)00082-3
  6. Huh, N.S., Kim, Y.J. and Kim, Y.J., 2001, 'Application of Enhanced Reference Stress Method to Nuclear Piping LBB Analysis: Finite Element Validation,' Transactions of the KSME(A), Vol. 25, No. 4, pp. 74l-747
  7. 'ABAQUS Ver. 5.8 - User's Manual,' Hibbitt, Karlson & Sorensen, Inc., 1999
  8. Norris, D.M. and Chexal, B., 1987, 'PICEP: Pipe Crack Evaluation Program,' EPRl NP 3596-SR
  9. Scott, P., Olson, R., Marshall, C., Rudland, D., Francini, R., Wolterman, R., Hopper, A. and Wilkowski, G., 1996, 'Pipe System Experiments with Circumferential Cracks in Straight-Pipe Locations,' NUREG/CR-6389, USNRC
  10. 'Pipe Fracture Encyclopedia, Vol. 1-Computer Program to Calculate Ramberg-Osgood Parameters for a Stress-Strain Curve,' Battelle, 1997
  11. Schwalbe, K.H., Zerbst, U., Kim, Y.J., Brocks, W., Comec, A., Heerens, J. and Amstutz, H., 1998, 'EFAM-ETM 97-The ETM Method for Assessing the Significance of Crack-like Defects in Engineering Structures, Comprising the Versions ETM 97/1 and ETM 97/2,' GKSS Report GKSS 98/E/6
  12. 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
  13. Kim, Y.J., 1998, 'Note on Y/T vs. n for SINTAP Procedure: Continuous and Dis-continuous Hardening,' Document generated within Brite-Euram Project 1426-Structural Integrity Assessment Procedures for European Industry-SINTAP
  14. Bannister, A.C., Ruiz Ocejo, J. and Gutierrez-Solana, F., 2000, 'Implications of the Yield Stress/Tensile Stress Ratio to the SINTAP Failure Assessment Diagrams for Homogeneous Materials,' Engineering Fracture Mechanics, Vol. 67, pp. 547-562 https://doi.org/10.1016/S0013-7944(00)00073-4