Seawater Effect on Fatigue Behaviour of Notched Carbon/Epoxy Laminates
This paper studies the effect of seawater immersion on the fatigue behavior of notched carbon/epoxy laminates. Rectangular cross-section specimens with a central hole were immersed in natural and artificial seawater for different immersion times (0, 30 and 60 days), being the water absorption rate e...
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MDPI AG
2021-12-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/11/24/11939 |
| _version_ | 1827674238839947264 |
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| author | Ricardo Branco Paulo N. B. Reis Maria A. Neto José D. Costa Ana M. Amaro |
| author_facet | Ricardo Branco Paulo N. B. Reis Maria A. Neto José D. Costa Ana M. Amaro |
| author_sort | Ricardo Branco |
| collection | DOAJ |
| description | This paper studies the effect of seawater immersion on the fatigue behavior of notched carbon/epoxy laminates. Rectangular cross-section specimens with a central hole were immersed in natural and artificial seawater for different immersion times (0, 30 and 60 days), being the water absorption rate evaluated over time. After that, fatigue tests were performed under uniaxial cyclic loading using a stress ratio equal to 0.1. After the tests, the optical microscopy technique allowed the examination of the failure micro-mechanisms at the fracture surfaces. The results showed that saturation appeared before 30 days of immersion and that water absorption rates were similar for natural and artificial seawater. The S–N curves showed that the seawater immersion affects the fatigue strength, but there were no relevant effects associated with the type of seawater. Moreover, it was also clear that fatigue life was similar for long lives, close to 1 million cycles, regardless of the immersion time or the type of seawater. On the contrary, for short lives, near 10 thousand cycles, the stress amplitude of dry laminates was 1.2 higher than those immersed in seawater. The failure mechanisms were similar for all conditions, evidencing the fracture of axially aligned fibres and longitudinal delamination between layers. |
| first_indexed | 2024-03-10T04:36:44Z |
| format | Article |
| id | doaj.art-7f775ee11e9042a5ae1e359fd98e12be |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T04:36:44Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-7f775ee11e9042a5ae1e359fd98e12be2023-11-23T03:40:39ZengMDPI AGApplied Sciences2076-34172021-12-0111241193910.3390/app112411939Seawater Effect on Fatigue Behaviour of Notched Carbon/Epoxy LaminatesRicardo Branco0Paulo N. B. Reis1Maria A. Neto2José D. Costa3Ana M. Amaro4Department of Mechanical Engineering, CEMMPRE, University of Coimbra, 3030-788 Coimbra, PortugalDepartment of Mechanical Engineering, CEMMPRE, University of Coimbra, 3030-788 Coimbra, PortugalDepartment of Mechanical Engineering, CEMMPRE, University of Coimbra, 3030-788 Coimbra, PortugalDepartment of Mechanical Engineering, CEMMPRE, University of Coimbra, 3030-788 Coimbra, PortugalDepartment of Mechanical Engineering, CEMMPRE, University of Coimbra, 3030-788 Coimbra, PortugalThis paper studies the effect of seawater immersion on the fatigue behavior of notched carbon/epoxy laminates. Rectangular cross-section specimens with a central hole were immersed in natural and artificial seawater for different immersion times (0, 30 and 60 days), being the water absorption rate evaluated over time. After that, fatigue tests were performed under uniaxial cyclic loading using a stress ratio equal to 0.1. After the tests, the optical microscopy technique allowed the examination of the failure micro-mechanisms at the fracture surfaces. The results showed that saturation appeared before 30 days of immersion and that water absorption rates were similar for natural and artificial seawater. The S–N curves showed that the seawater immersion affects the fatigue strength, but there were no relevant effects associated with the type of seawater. Moreover, it was also clear that fatigue life was similar for long lives, close to 1 million cycles, regardless of the immersion time or the type of seawater. On the contrary, for short lives, near 10 thousand cycles, the stress amplitude of dry laminates was 1.2 higher than those immersed in seawater. The failure mechanisms were similar for all conditions, evidencing the fracture of axially aligned fibres and longitudinal delamination between layers.https://www.mdpi.com/2076-3417/11/24/11939composite laminatesopen holesseawater effectfatigue lifemechanical testing |
| spellingShingle | Ricardo Branco Paulo N. B. Reis Maria A. Neto José D. Costa Ana M. Amaro Seawater Effect on Fatigue Behaviour of Notched Carbon/Epoxy Laminates Applied Sciences composite laminates open holes seawater effect fatigue life mechanical testing |
| title | Seawater Effect on Fatigue Behaviour of Notched Carbon/Epoxy Laminates |
| title_full | Seawater Effect on Fatigue Behaviour of Notched Carbon/Epoxy Laminates |
| title_fullStr | Seawater Effect on Fatigue Behaviour of Notched Carbon/Epoxy Laminates |
| title_full_unstemmed | Seawater Effect on Fatigue Behaviour of Notched Carbon/Epoxy Laminates |
| title_short | Seawater Effect on Fatigue Behaviour of Notched Carbon/Epoxy Laminates |
| title_sort | seawater effect on fatigue behaviour of notched carbon epoxy laminates |
| topic | composite laminates open holes seawater effect fatigue life mechanical testing |
| url | https://www.mdpi.com/2076-3417/11/24/11939 |
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