Tarnowski, K.M., Nikbin, K.M., Dean, D.W. et al. (1 more author) (2018) Improvements in the Measurement of Creep Crack Initiation and Growth Using Potential Drop. International Journal of Solids and Structures, 134. pp. 229-248. ISSN 0020-7683
Abstract
To predict the residual life of components operating in the creep regime, it is vital to accurately identify crack initiation, and measure subsequent crack growth, in laboratory tests. Potential drop (PD) measurements, used for this purpose, are susceptible to errors caused by the accumulation of creep strain. For creep ductile materials, this can result in highly conservative crack initiation models and the implementation of unnecessary inspection and maintenance programmes that can cost millions of pounds in lost revenue. Conversely, the crack growth models can be non-conservative.
Using a novel combination of interrupted creep crack growth (CCG) tests and sequentially coupled structural-electrical finite element analyses a new method of interpreting PD data has been developed and validated. It uses an increase in gradient on a plot of PD vs. load-line displacement to accurately identify crack initiation. This has been compared to the current method in ASTM E1457-15 by reanalysing data from CCG tests performed on a range of materials at various temperatures and loads. The initiation times, measured using the current ASTM method, were underestimated by factors of up to 23 and the subsequent crack growth rates were underestimated by factors of up to 1.5.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 Elsevier. This is an author produced version of a paper subsequently published in International Journal of Solids and Structures. Uploaded in accordance with the publisher's self-archiving policy. Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/). |
Keywords: | Creep crack initiation; Creep crack growth; Potential drop method; Strain; Finite element analysis |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Mechanical Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 22 Dec 2017 12:09 |
Last Modified: | 09 Apr 2024 15:05 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.ijsolstr.2017.10.037 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:125525 |
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