Using DIC techniques to measure strain ranges inside the cyclic plastic zone ahead of a fatigue crack tip
A stereo microscope coupled to a 3-D Digital Image Correlation system is used to measure strain ranges on the cyclic plastic zone ahead of a fatigue crack-tip. First, a very refined speckle pattern is applied on the surface of a disk-shaped compact tension specimen of 1020 low-C steel by spraying to...
Saved in:
Main Authors: | , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Gruppo Italiano Frattura
2019-05-01
|
Series: | Fracture and Structural Integrity |
Subjects: | |
Online Access: | https://www.fracturae.com/index.php/fis/article/view/2497 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
_version_ | 1841562891126308864 |
---|---|
author | Giancarlo luis Gómez Gonzáles Julián Andrés Ortiz González Jaime Tupiassú Pinho de Castro José Luiz de França Freire |
author_facet | Giancarlo luis Gómez Gonzáles Julián Andrés Ortiz González Jaime Tupiassú Pinho de Castro José Luiz de França Freire |
author_sort | Giancarlo luis Gómez Gonzáles |
collection | DOAJ |
description | A stereo microscope coupled to a 3-D Digital Image Correlation system is used to measure strain ranges on the cyclic plastic zone ahead of a fatigue crack-tip. First, a very refined speckle pattern is applied on the surface of a disk-shaped compact tension specimen of 1020 low-C steel by spraying toner powder over a layer of white paint, a suitable technique to produce the very small dots needed to map surface strain loops on that small region. This technique can achieve enough resolution to measure elastoplastic strain ranges Δε near the crack tip, which cause damage accumulation inside the cyclic plastic zone as the crack grows. The applied technique can identify as well the effects of other nonlinear phenomena that happen in the near-tip region, such as crack closure. Therefore, such measurements can be used to verify the validity of the hypotheses behind the main fatigue crack growth models. |
format | Article |
id | doaj-art-f680a1aac6da4ac2b1632b66beda3d76 |
institution | Kabale University |
issn | 1971-8993 |
language | English |
publishDate | 2019-05-01 |
publisher | Gruppo Italiano Frattura |
record_format | Article |
series | Fracture and Structural Integrity |
spelling | doaj-art-f680a1aac6da4ac2b1632b66beda3d762025-01-03T00:39:47ZengGruppo Italiano FratturaFracture and Structural Integrity1971-89932019-05-011349Using DIC techniques to measure strain ranges inside the cyclic plastic zone ahead of a fatigue crack tipGiancarlo luis Gómez Gonzáles0Julián Andrés Ortiz González1Jaime Tupiassú Pinho de Castro2José Luiz de França Freire3Pontifical Catholic University of Rio de Janeiro, PUC-Rio.Pontifical Catholic University of Rio de Janeiro, PUC-Rio.Pontifical Catholic University of Rio de Janeiro, PUC-Rio.Pontifical Catholic University of Rio de Janeiro, PUC-Rio.A stereo microscope coupled to a 3-D Digital Image Correlation system is used to measure strain ranges on the cyclic plastic zone ahead of a fatigue crack-tip. First, a very refined speckle pattern is applied on the surface of a disk-shaped compact tension specimen of 1020 low-C steel by spraying toner powder over a layer of white paint, a suitable technique to produce the very small dots needed to map surface strain loops on that small region. This technique can achieve enough resolution to measure elastoplastic strain ranges Δε near the crack tip, which cause damage accumulation inside the cyclic plastic zone as the crack grows. The applied technique can identify as well the effects of other nonlinear phenomena that happen in the near-tip region, such as crack closure. Therefore, such measurements can be used to verify the validity of the hypotheses behind the main fatigue crack growth models.https://www.fracturae.com/index.php/fis/article/view/2497Digital Image CorrelationCrack-tip strain fieldCyclic plastic zoneDamage ahead of the crack tipStereo microscope measurements |
spellingShingle | Giancarlo luis Gómez Gonzáles Julián Andrés Ortiz González Jaime Tupiassú Pinho de Castro José Luiz de França Freire Using DIC techniques to measure strain ranges inside the cyclic plastic zone ahead of a fatigue crack tip Fracture and Structural Integrity Digital Image Correlation Crack-tip strain field Cyclic plastic zone Damage ahead of the crack tip Stereo microscope measurements |
title | Using DIC techniques to measure strain ranges inside the cyclic plastic zone ahead of a fatigue crack tip |
title_full | Using DIC techniques to measure strain ranges inside the cyclic plastic zone ahead of a fatigue crack tip |
title_fullStr | Using DIC techniques to measure strain ranges inside the cyclic plastic zone ahead of a fatigue crack tip |
title_full_unstemmed | Using DIC techniques to measure strain ranges inside the cyclic plastic zone ahead of a fatigue crack tip |
title_short | Using DIC techniques to measure strain ranges inside the cyclic plastic zone ahead of a fatigue crack tip |
title_sort | using dic techniques to measure strain ranges inside the cyclic plastic zone ahead of a fatigue crack tip |
topic | Digital Image Correlation Crack-tip strain field Cyclic plastic zone Damage ahead of the crack tip Stereo microscope measurements |
url | https://www.fracturae.com/index.php/fis/article/view/2497 |
work_keys_str_mv | AT giancarloluisgomezgonzales usingdictechniquestomeasurestrainrangesinsidethecyclicplasticzoneaheadofafatiguecracktip AT julianandresortizgonzalez usingdictechniquestomeasurestrainrangesinsidethecyclicplasticzoneaheadofafatiguecracktip AT jaimetupiassupinhodecastro usingdictechniquestomeasurestrainrangesinsidethecyclicplasticzoneaheadofafatiguecracktip AT joseluizdefrancafreire usingdictechniquestomeasurestrainrangesinsidethecyclicplasticzoneaheadofafatiguecracktip |