Sources of Scatter in Creep/Fatigue Crack Growth Testing and Their Impact on Plant Assessment
- 64 Downloads
The procedures used in high temperature plant assessment are mostly deterministic thus requiring appropriate, specific data input to determine the remaining life of components containing design allowable defects. However, because high temperature test data contain uncertainties and scatter by their nature, the life assessment predictions may differ largely. In most cases it is based on the worst combination of input data resulting in a high conservative prediction. Thus achieved predictions do not take any optimisation of costs or improvement of plant efficiency into account. The present paper reports on the assessment procedures and the sources of scatter in creep/fatigue crack growth data. Their impact on the life assessment of the engineering structures following the deterministic and probabilistic methods is reported.
IIW-Thesaurus keywordsCrack initiation Crack propagation Creep Evaluation Fatigue cracks High temperature Lifetime Prediction Reference lists Statistical methods
Unable to display preview. Download preview PDF.
- Dogan B., Nikbin K., Webster G.A, Ceyhan U., Petrovski B., Dean D.W. Ainsworth R.A., Chapuliot S., Holdsworth S.: Code of practice for high temperature crack initiation and growth testing of weldments, IIW Doc., Res. XI #1, Submitted to IIW SC STAND for ISO standardisation, 2005.Google Scholar
- Jovanovic A., Colantoni D., Balos D., Wagemann G., Le Mat Hamata N., Deschanels H.: Alias-HIDA, A knowldge-based system for probabilistic and sensitivity analysis of creep and fatigue crack growth in high temperature components, OMMI (www.ommi.co.uk), August 2004, Vol. 3, Issue 2.
- Yatomi M., Nikbin K.: Life management in creep/fatigue using deterministic and probabilistic modeling, EPRI, Conference on “Life Management”, Orlando, March 2002.Google Scholar
- Anderson T.W., Finn J.D.: The new statistical analysis of data, 96 Edition, Springer Verlag, December 1996.Google Scholar
- R5, Assessment procedure for the high temperature response of structures, Issue 3, British Energy Generation, Gloucester 2003.Google Scholar
- Ainsworth R.A.: Sensitivity analysis in creep crack growth — British Energy Experience, Int. HIDA — 4 Conf., Cambridge, UK, 20–22 Sept. 2004.Google Scholar
- ASTM E1457–00, Standard test method for measurement of creep crack growth rates in metals, ASTM 03.01, Philadelphia: ASTM 2000, PA 19103, USA.Google Scholar
- ESIS TC11 High Temperature Mechanical Testing Committee (HTMTC), Working Group on High Temperature Testing of Weldments.Google Scholar
- Dogan B., Petrovski B., Ceyhan U.: Significance of creep crack initiation for defect assessment, Proc. Int. Conf. BALTICA VI on Life Management and Maintenance for Power Plants, Eds J Veivo and P Auerkari, VTT Symp. 234, 2004, Vol. 2, Espoo, Finland, pp. 595–607.Google Scholar
- Joensson M., Le Mat Hamata N., Concari S., Vrhovac M., Albuquerque J.M., Deschanels H., Proc. Int. HIDA-4 Conf., Churchill College, Cambridge, UK, 21–22 Sept. 2004, Eds. N. Le Mat Hamata and I.A. Shibli, 2004, pp. 3.1–3.15.Google Scholar
- Ainsworth R.A., Cosso G.L., Dogan B., Holdsworth S., Korous J., Marcelles I., Mueller F.: An overview of the creep module of the FITNET FFS Procedure, Proceedings of the International Conference on Fitness-for-Service FITNET 2006, 17–19 May 2006 Amsterdam, Ed. by M. Koçak, GKSS Publications, ISBN 978-3-00-021084–6, 2007.Google Scholar
- ECCC — Advanced Creep Project, Procedures, Vol. 9, part 2, ETD, UK, 2005.Google Scholar
- Dogan B., Ceyhan U.: High temperature failure assessment of weldments, ECF16, due 3–7.7.2006, Alexandroupolis, Greece.Google Scholar
- Korous J.: Probabilistic reliability assessment of piping systems (in Czech), Proc. of Conf. Structural Reliability, Ostrava, CZ, 2005, pp. 181–186.Google Scholar
- R6, Assessment of integrity of structures containing defects, Procedure R6, Revision 3, Gloucester, UK: Nuclear Electric Ltd., 1997.Google Scholar
- Dieter G.: Mechanical Metallurgy, McGraw-Hill Science/Engineering/Math, 1986.Google Scholar
- Ewald J., Keienburg G.: A two criteria diagram for creep crack initiation, Int. Conf. Creep, Tokyo, 173–178, April 1986.Google Scholar