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Effect of Specimen Thickness and Stress Intensity Factor Range on Plasticity-Induced Fatigue Crack Closure in A7075-T6 Alloy
Fatigue crack growth experiments are performed using A7075-T6 compact tension (CT) specimens with various thicknesses t (1–21 mm). The stress intensity factor at the crack opening level K(op) is measured, and the effects of t and the stress intensity factor range ΔK on K(op) are investigated. In add...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7866977/ https://www.ncbi.nlm.nih.gov/pubmed/33572686 http://dx.doi.org/10.3390/ma14030664 |
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author | Masuda, Kenichi Ishihara, Sotomi Oguma, Noriyasu |
author_facet | Masuda, Kenichi Ishihara, Sotomi Oguma, Noriyasu |
author_sort | Masuda, Kenichi |
collection | PubMed |
description | Fatigue crack growth experiments are performed using A7075-T6 compact tension (CT) specimens with various thicknesses t (1–21 mm). The stress intensity factor at the crack opening level K(op) is measured, and the effects of t and the stress intensity factor range ΔK on K(op) are investigated. In addition, the change in K(op) value due to specimen surface removal is investigated. Furthermore, we clarify that the radius of curvature of the leading edge of the fatigue crack decreases as t becomes thinner. Using the three-dimensional elastoplastic finite element method, the amount of plastic lateral contraction (depression depth d) at the crack tip after fatigue loading is calculated quantitatively. The following main experimental results are obtained: In the region where ΔK is 5 MPam(1/2) or higher, the rate of fatigue crack growth da/dN at a constant ΔK value increases as t increases from 1 to 11 mm. The da/dN between t = 11 and 21 mm is the same. Meanwhile, in the region where ΔK is less than 5 MPam(1/2), the effect of t on da/dN is not observed. The effects of t and ΔK on the da/dN–ΔK relationship are considered physically and quantitatively based on d. |
format | Online Article Text |
id | pubmed-7866977 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-78669772021-02-07 Effect of Specimen Thickness and Stress Intensity Factor Range on Plasticity-Induced Fatigue Crack Closure in A7075-T6 Alloy Masuda, Kenichi Ishihara, Sotomi Oguma, Noriyasu Materials (Basel) Article Fatigue crack growth experiments are performed using A7075-T6 compact tension (CT) specimens with various thicknesses t (1–21 mm). The stress intensity factor at the crack opening level K(op) is measured, and the effects of t and the stress intensity factor range ΔK on K(op) are investigated. In addition, the change in K(op) value due to specimen surface removal is investigated. Furthermore, we clarify that the radius of curvature of the leading edge of the fatigue crack decreases as t becomes thinner. Using the three-dimensional elastoplastic finite element method, the amount of plastic lateral contraction (depression depth d) at the crack tip after fatigue loading is calculated quantitatively. The following main experimental results are obtained: In the region where ΔK is 5 MPam(1/2) or higher, the rate of fatigue crack growth da/dN at a constant ΔK value increases as t increases from 1 to 11 mm. The da/dN between t = 11 and 21 mm is the same. Meanwhile, in the region where ΔK is less than 5 MPam(1/2), the effect of t on da/dN is not observed. The effects of t and ΔK on the da/dN–ΔK relationship are considered physically and quantitatively based on d. MDPI 2021-01-31 /pmc/articles/PMC7866977/ /pubmed/33572686 http://dx.doi.org/10.3390/ma14030664 Text en © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Masuda, Kenichi Ishihara, Sotomi Oguma, Noriyasu Effect of Specimen Thickness and Stress Intensity Factor Range on Plasticity-Induced Fatigue Crack Closure in A7075-T6 Alloy |
title | Effect of Specimen Thickness and Stress Intensity Factor Range on Plasticity-Induced Fatigue Crack Closure in A7075-T6 Alloy |
title_full | Effect of Specimen Thickness and Stress Intensity Factor Range on Plasticity-Induced Fatigue Crack Closure in A7075-T6 Alloy |
title_fullStr | Effect of Specimen Thickness and Stress Intensity Factor Range on Plasticity-Induced Fatigue Crack Closure in A7075-T6 Alloy |
title_full_unstemmed | Effect of Specimen Thickness and Stress Intensity Factor Range on Plasticity-Induced Fatigue Crack Closure in A7075-T6 Alloy |
title_short | Effect of Specimen Thickness and Stress Intensity Factor Range on Plasticity-Induced Fatigue Crack Closure in A7075-T6 Alloy |
title_sort | effect of specimen thickness and stress intensity factor range on plasticity-induced fatigue crack closure in a7075-t6 alloy |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7866977/ https://www.ncbi.nlm.nih.gov/pubmed/33572686 http://dx.doi.org/10.3390/ma14030664 |
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