No Cover Image

Journal article 23 views 7 downloads

Predictions of Crack Growth Rates, R-Ratio and Overload Effects Based on Smooth Specimen LCF Data and the Moving Plastic Stress Field Ahead of the Crack Tip

STEPHEN WILLIAMS, Mark Whittaker Orcid Logo, Mark Hardy

Materials, Volume: 19, Issue: 11, Pages: 2411 - 2411

Swansea University Authors: STEPHEN WILLIAMS, Mark Whittaker Orcid Logo

  • 72080.VOR.pdf

    PDF | Version of Record

    © 2026 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.

    Download (9.98MB)

Check full text

DOI (Published version): 10.3390/ma19112411

Abstract

The use of the stress intensity factor K to characterize the severity of crack tip stress fields is widespread throughout engineering. The relationship between K and the crack growth rate is then usually represented empirically by a straight line Paris law relationship on logarithmic axes. This stud...

Full description

Published in: Materials
ISSN: 1996-1944
Published: MDPI AG 2026
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa72080
first_indexed 2026-06-15T11:47:42Z
last_indexed 2026-06-16T04:32:36Z
id cronfa72080
recordtype SURis
fullrecord <?xml version="1.0"?><rfc1807><datestamp>2026-06-15T12:48:28.8555958</datestamp><bib-version>v2</bib-version><id>72080</id><entry>2026-06-15</entry><title>Predictions of Crack Growth Rates, R-Ratio and Overload Effects Based on Smooth Specimen LCF Data and the Moving Plastic Stress Field Ahead of the Crack Tip</title><swanseaauthors><author><sid>049a0935afb0021860a07023deb70165</sid><firstname>STEPHEN</firstname><surname>WILLIAMS</surname><name>STEPHEN WILLIAMS</name><active>true</active><ethesisStudent>false</ethesisStudent></author><author><sid>a146c6d442cb2c466d096179f9ac97ca</sid><ORCID>0000-0002-5854-0726</ORCID><firstname>Mark</firstname><surname>Whittaker</surname><name>Mark Whittaker</name><active>true</active><ethesisStudent>false</ethesisStudent></author></swanseaauthors><date>2026-06-15</date><abstract>The use of the stress intensity factor K to characterize the severity of crack tip stress fields is widespread throughout engineering. The relationship between K and the crack growth rate is then usually represented empirically by a straight line Paris law relationship on logarithmic axes. This study develops an analytical relationship between the two by linking crack growth to the accumulation of fatigue damage ahead of the moving crack tip. A stress-based fatigue model was used, with inputs from plastic 2D plane stress FE analyses representing an edge crack by a sharp semi-circular notch. Stress&#x2013;distance profiles ahead of the crack tip were extracted at the maximum and minimum points of a range of fatigue loading cycles. These were then used with data from smooth specimen LCF tests to predict the build-up of fatigue damage at regularly spaced locations ahead of the crack tip and hence crack growth rates. Full da/dN&#x2013;&#x394;K curves were generated for the nickel-based superalloy RR1000 at 20 &#xB0;C with loading R-ratios of 0, &#x2212;1 and 0.5. The R = 0 and R = &#x2212;1 crack growth rate predictions agreed well with experimental data, as did the steeper growth rate slope calculated at R = 0.5. The method was then extended to predict overload behaviour.</abstract><type>Journal Article</type><journal>Materials</journal><volume>19</volume><journalNumber>11</journalNumber><paginationStart>2411</paginationStart><paginationEnd>2411</paginationEnd><publisher>MDPI AG</publisher><placeOfPublication/><isbnPrint/><isbnElectronic/><issnPrint/><issnElectronic>1996-1944</issnElectronic><keywords>crack growth; LCF; strip yield models; plasticity; R-ratio effects; overloads</keywords><publishedDay>5</publishedDay><publishedMonth>6</publishedMonth><publishedYear>2026</publishedYear><publishedDate>2026-06-05</publishedDate><doi>10.3390/ma19112411</doi><url/><notes/><college>COLLEGE NANME</college><CollegeCode>COLLEGE CODE</CollegeCode><institution>Swansea University</institution><apcterm>Other</apcterm><funders>The work was carried out as part of an EPSRC-funded iCASE Ph.D. programme under project EP/V519601/1 with top-up funding from Rolls-Royce plc.</funders><projectreference/><lastEdited>2026-06-15T12:48:28.8555958</lastEdited><Created>2026-06-15T12:39:31.8228496</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Engineering and Applied Sciences - Materials Science and Engineering</level></path><authors><author><firstname>STEPHEN</firstname><surname>WILLIAMS</surname><order>1</order></author><author><firstname>Mark</firstname><surname>Whittaker</surname><orcid>0000-0002-5854-0726</orcid><order>2</order></author><author><firstname>Mark</firstname><surname>Hardy</surname><order>3</order></author></authors><documents><document><filename>72080__36969__5a10e8f2a20947509ff918123f3add8c.pdf</filename><originalFilename>72080.VOR.pdf</originalFilename><uploaded>2026-06-15T12:46:50.8461409</uploaded><type>Output</type><contentLength>10468685</contentLength><contentType>application/pdf</contentType><version>Version of Record</version><cronfaStatus>true</cronfaStatus><documentNotes>&#xA9; 2026 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.</documentNotes><copyrightCorrect>true</copyrightCorrect><language>eng</language><licence>https://creativecommons.org/licenses/by/4.0/</licence></document></documents><OutputDurs/></rfc1807>
spelling 2026-06-15T12:48:28.8555958 v2 72080 2026-06-15 Predictions of Crack Growth Rates, R-Ratio and Overload Effects Based on Smooth Specimen LCF Data and the Moving Plastic Stress Field Ahead of the Crack Tip 049a0935afb0021860a07023deb70165 STEPHEN WILLIAMS STEPHEN WILLIAMS true false a146c6d442cb2c466d096179f9ac97ca 0000-0002-5854-0726 Mark Whittaker Mark Whittaker true false 2026-06-15 The use of the stress intensity factor K to characterize the severity of crack tip stress fields is widespread throughout engineering. The relationship between K and the crack growth rate is then usually represented empirically by a straight line Paris law relationship on logarithmic axes. This study develops an analytical relationship between the two by linking crack growth to the accumulation of fatigue damage ahead of the moving crack tip. A stress-based fatigue model was used, with inputs from plastic 2D plane stress FE analyses representing an edge crack by a sharp semi-circular notch. Stress–distance profiles ahead of the crack tip were extracted at the maximum and minimum points of a range of fatigue loading cycles. These were then used with data from smooth specimen LCF tests to predict the build-up of fatigue damage at regularly spaced locations ahead of the crack tip and hence crack growth rates. Full da/dN–ΔK curves were generated for the nickel-based superalloy RR1000 at 20 °C with loading R-ratios of 0, −1 and 0.5. The R = 0 and R = −1 crack growth rate predictions agreed well with experimental data, as did the steeper growth rate slope calculated at R = 0.5. The method was then extended to predict overload behaviour. Journal Article Materials 19 11 2411 2411 MDPI AG 1996-1944 crack growth; LCF; strip yield models; plasticity; R-ratio effects; overloads 5 6 2026 2026-06-05 10.3390/ma19112411 COLLEGE NANME COLLEGE CODE Swansea University Other The work was carried out as part of an EPSRC-funded iCASE Ph.D. programme under project EP/V519601/1 with top-up funding from Rolls-Royce plc. 2026-06-15T12:48:28.8555958 2026-06-15T12:39:31.8228496 Faculty of Science and Engineering School of Engineering and Applied Sciences - Materials Science and Engineering STEPHEN WILLIAMS 1 Mark Whittaker 0000-0002-5854-0726 2 Mark Hardy 3 72080__36969__5a10e8f2a20947509ff918123f3add8c.pdf 72080.VOR.pdf 2026-06-15T12:46:50.8461409 Output 10468685 application/pdf Version of Record true © 2026 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. true eng https://creativecommons.org/licenses/by/4.0/
title Predictions of Crack Growth Rates, R-Ratio and Overload Effects Based on Smooth Specimen LCF Data and the Moving Plastic Stress Field Ahead of the Crack Tip
spellingShingle Predictions of Crack Growth Rates, R-Ratio and Overload Effects Based on Smooth Specimen LCF Data and the Moving Plastic Stress Field Ahead of the Crack Tip
STEPHEN WILLIAMS
Mark Whittaker
title_short Predictions of Crack Growth Rates, R-Ratio and Overload Effects Based on Smooth Specimen LCF Data and the Moving Plastic Stress Field Ahead of the Crack Tip
title_full Predictions of Crack Growth Rates, R-Ratio and Overload Effects Based on Smooth Specimen LCF Data and the Moving Plastic Stress Field Ahead of the Crack Tip
title_fullStr Predictions of Crack Growth Rates, R-Ratio and Overload Effects Based on Smooth Specimen LCF Data and the Moving Plastic Stress Field Ahead of the Crack Tip
title_full_unstemmed Predictions of Crack Growth Rates, R-Ratio and Overload Effects Based on Smooth Specimen LCF Data and the Moving Plastic Stress Field Ahead of the Crack Tip
title_sort Predictions of Crack Growth Rates, R-Ratio and Overload Effects Based on Smooth Specimen LCF Data and the Moving Plastic Stress Field Ahead of the Crack Tip
author_id_str_mv 049a0935afb0021860a07023deb70165
a146c6d442cb2c466d096179f9ac97ca
author_id_fullname_str_mv 049a0935afb0021860a07023deb70165_***_STEPHEN WILLIAMS
a146c6d442cb2c466d096179f9ac97ca_***_Mark Whittaker
author STEPHEN WILLIAMS
Mark Whittaker
author2 STEPHEN WILLIAMS
Mark Whittaker
Mark Hardy
format Journal article
container_title Materials
container_volume 19
container_issue 11
container_start_page 2411
publishDate 2026
institution Swansea University
issn 1996-1944
doi_str_mv 10.3390/ma19112411
publisher MDPI AG
college_str Faculty of Science and Engineering
hierarchytype
hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Engineering and Applied Sciences - Materials Science and Engineering{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Materials Science and Engineering
document_store_str 1
active_str 0
description The use of the stress intensity factor K to characterize the severity of crack tip stress fields is widespread throughout engineering. The relationship between K and the crack growth rate is then usually represented empirically by a straight line Paris law relationship on logarithmic axes. This study develops an analytical relationship between the two by linking crack growth to the accumulation of fatigue damage ahead of the moving crack tip. A stress-based fatigue model was used, with inputs from plastic 2D plane stress FE analyses representing an edge crack by a sharp semi-circular notch. Stress–distance profiles ahead of the crack tip were extracted at the maximum and minimum points of a range of fatigue loading cycles. These were then used with data from smooth specimen LCF tests to predict the build-up of fatigue damage at regularly spaced locations ahead of the crack tip and hence crack growth rates. Full da/dN–ΔK curves were generated for the nickel-based superalloy RR1000 at 20 °C with loading R-ratios of 0, −1 and 0.5. The R = 0 and R = −1 crack growth rate predictions agreed well with experimental data, as did the steeper growth rate slope calculated at R = 0.5. The method was then extended to predict overload behaviour.
published_date 2026-06-05T05:31:09Z
_version_ 1868760685747372032
score 11.110258

Similar Items