0
Research Papers: Design and Analysis

Systematic Evaluation of Creep-Fatigue Life Prediction Methods for Various Alloys

[+] Author and Article Information
Yukio Takahashi

Central Research Institute of Electric
Power Industry,
Yokosuka, Kanagawa240-0196, Japan
e-mail: yukio@criepi.denken.or.jp

Bilal Dogan

Consultant,
Charlotte, NC 28262-8550

David Gandy

Electric Power Research Institute,
Charlotte, NC 28262-8550

Contributed by the Pressure Vessel and Piping Division of ASME for publication in the Journal of Pressure Vessel Technology. Manuscript received June 21, 2011; final manuscript received December 3, 2012; published online October 7, 2013. Assoc. Editor: Osamu Watanabe.

J. Pressure Vessel Technol 135(6), 061204 (Oct 07, 2013) (10 pages) Paper No: PVT-11-1141; doi: 10.1115/1.4024436 History: Received June 21, 2011; Revised December 03, 2012

Failure under creep-fatigue interaction is receiving an increasing interest due to an increased number of start-up and shut-downs in fossil power generation plants as well as development of newer nuclear power plants employing low-pressure coolant. Such situations have prompted the studies on creep-fatigue interaction and the developments of various approaches for evaluating its significance in design as well as remaining life evaluation, but most of them are fragmental and rather limited in terms of materials and test conditions covered. Therefore, applicability of the proposed approaches to different materials or even different temperatures is uncertain in many cases. The present work was conducted in order to comparably evaluate the representative approaches used in the prediction of failure life under creep-fatigue conditions as well as their modifications, by systematically applying them to available test data on a wide range of materials which have been used or are planned to be used in various types of power generation plants. The following observations have been made from this exercise: (i) The time fraction model has a tendency to be nonconservative in general, especially at low temperature and small strain ranges. Because of the large scatter of the total damage, this shortcoming would be difficult to cover by the consideration of creep-fatigue interaction in a simple manner. (ii) The classical ductility exhaustion model showed a general tendency to be overly conservative in many situations, especially at small strain ranges. (iii) The modified ductility exhaustion model based on the redefinition of creep damage showed improved predictability with a slightly nonconservative tendency. (iv) Energy-based ductility exhaustion model developed in this study seems to show the best predictability among the four procedures in an overall sense although some dependency on strain range and materials was observed.

FIGURES IN THIS ARTICLE
<>
Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 2

Variation of rupture energy density with time to rupture (type 304 SS)

Grahic Jump Location
Fig. 1

Variation of rupture elongation with time to rupture (type 304 SS)

Grahic Jump Location
Fig. 6

Relation between experimental failure time and accumulated total damage: (a) Time fraction model, (b) classical ductility exhaustion model, (c) modified ductility exhaustion, and (d) energy-based approach

Grahic Jump Location
Fig. 7

Comparison of inelastic strain rates under pure creep and creep-fatigue conditions

Grahic Jump Location
Fig. 3

Accumulated damages at failure estimated by each model: (a) Time fraction model, (b) classical ductility exhaustion model, (c) modified ductility exhaustion model, and (d) energy-based approach

Grahic Jump Location
Fig. 4

Temperature-dependency of total damage: (a) Time fraction model, (b) classical ductility exhaustion model, (c) modified ductility exhaustion model, and (d) energy-based approach

Grahic Jump Location
Fig. 5

Strain range-dependency of total damage: (a) Time fraction model, (b) classical ductility exhaustion model, (c) modified ductility exhaustion model, and (d) Energy-based approach

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In