Online and Ex Situ Damage Characterization Techniques for Fiber-Reinforced Composites under Ultrasonic Cyclic Three-Point Bending
With ultrasonic fatigue testing (UFT), it is possible to investigate the damage initiation and accumulation from the weakest link of the composite material in the very high cycle fatigue (VHCF) regime in a shorter time frame than conventional fatigue testing. However, the thermal influence on the me...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-03-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/16/6/803 |
| _version_ | 1797239495155777536 |
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| author | Aravind Premanand Mario Prescher Michael Rienks Lutz Kirste Frank Balle |
| author_facet | Aravind Premanand Mario Prescher Michael Rienks Lutz Kirste Frank Balle |
| author_sort | Aravind Premanand |
| collection | DOAJ |
| description | With ultrasonic fatigue testing (UFT), it is possible to investigate the damage initiation and accumulation from the weakest link of the composite material in the very high cycle fatigue (VHCF) regime in a shorter time frame than conventional fatigue testing. However, the thermal influence on the mechanical fatigue of composites and the scatter in fatigue data for composites under ultrasonic cyclic three-point bending loading still need to be investigated. In this study, we conducted interrupted constant-amplitude fatigue experiments on a carbon-fiber satin-fabric reinforced in poly-ether-ketone-ketone (CF-PEKK) composite material. These experiments were carried out using a UFT system, which operates at a cyclic frequency of 20 kHz with a pulse–pause sequence. Various parameters, such as the CF-PEKK specimen’s surface temperature, acoustic activity, and the ultrasonic generator’s input resonance parameters, were measured during cyclic loading. During experiment interruption, stiffness measurement and volumetric damage characterization in the CF-PEKK specimens using 3D X-ray microscopy (XRM) were performed. The locations of damage initiation and accumulation and their influence on the changes in in situ parameters were characterized. Under fixed loading conditions, damage accumulation occurred at different locations, leading to scattering in fatigue life data. Further, the damage population decreased from the surface to the bulk of the composite material. |
| first_indexed | 2024-04-24T17:52:26Z |
| format | Article |
| id | doaj.art-189e0ad1efe8478d8d52f77b5a409e75 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-04-24T17:52:26Z |
| publishDate | 2024-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-189e0ad1efe8478d8d52f77b5a409e752024-03-27T14:01:22ZengMDPI AGPolymers2073-43602024-03-0116680310.3390/polym16060803Online and Ex Situ Damage Characterization Techniques for Fiber-Reinforced Composites under Ultrasonic Cyclic Three-Point BendingAravind Premanand0Mario Prescher1Michael Rienks2Lutz Kirste3Frank Balle4Department for Sustainable Systems Engineering (INATECH), Faculty of Engineering, University of Freiburg, 79110 Freiburg, GermanyFraunhofer Institute for Applied Solid State Physics (IAF), 79108 Freiburg, GermanyDepartment for Sustainable Systems Engineering (INATECH), Faculty of Engineering, University of Freiburg, 79110 Freiburg, GermanyFraunhofer Institute for Applied Solid State Physics (IAF), 79108 Freiburg, GermanyDepartment for Sustainable Systems Engineering (INATECH), Faculty of Engineering, University of Freiburg, 79110 Freiburg, GermanyWith ultrasonic fatigue testing (UFT), it is possible to investigate the damage initiation and accumulation from the weakest link of the composite material in the very high cycle fatigue (VHCF) regime in a shorter time frame than conventional fatigue testing. However, the thermal influence on the mechanical fatigue of composites and the scatter in fatigue data for composites under ultrasonic cyclic three-point bending loading still need to be investigated. In this study, we conducted interrupted constant-amplitude fatigue experiments on a carbon-fiber satin-fabric reinforced in poly-ether-ketone-ketone (CF-PEKK) composite material. These experiments were carried out using a UFT system, which operates at a cyclic frequency of 20 kHz with a pulse–pause sequence. Various parameters, such as the CF-PEKK specimen’s surface temperature, acoustic activity, and the ultrasonic generator’s input resonance parameters, were measured during cyclic loading. During experiment interruption, stiffness measurement and volumetric damage characterization in the CF-PEKK specimens using 3D X-ray microscopy (XRM) were performed. The locations of damage initiation and accumulation and their influence on the changes in in situ parameters were characterized. Under fixed loading conditions, damage accumulation occurred at different locations, leading to scattering in fatigue life data. Further, the damage population decreased from the surface to the bulk of the composite material.https://www.mdpi.com/2073-4360/16/6/803ultrasonic fatigue testingcarbon fiber reinforced polymersonline monitoringfatigue damageX-ray microscopy |
| spellingShingle | Aravind Premanand Mario Prescher Michael Rienks Lutz Kirste Frank Balle Online and Ex Situ Damage Characterization Techniques for Fiber-Reinforced Composites under Ultrasonic Cyclic Three-Point Bending Polymers ultrasonic fatigue testing carbon fiber reinforced polymers online monitoring fatigue damage X-ray microscopy |
| title | Online and Ex Situ Damage Characterization Techniques for Fiber-Reinforced Composites under Ultrasonic Cyclic Three-Point Bending |
| title_full | Online and Ex Situ Damage Characterization Techniques for Fiber-Reinforced Composites under Ultrasonic Cyclic Three-Point Bending |
| title_fullStr | Online and Ex Situ Damage Characterization Techniques for Fiber-Reinforced Composites under Ultrasonic Cyclic Three-Point Bending |
| title_full_unstemmed | Online and Ex Situ Damage Characterization Techniques for Fiber-Reinforced Composites under Ultrasonic Cyclic Three-Point Bending |
| title_short | Online and Ex Situ Damage Characterization Techniques for Fiber-Reinforced Composites under Ultrasonic Cyclic Three-Point Bending |
| title_sort | online and ex situ damage characterization techniques for fiber reinforced composites under ultrasonic cyclic three point bending |
| topic | ultrasonic fatigue testing carbon fiber reinforced polymers online monitoring fatigue damage X-ray microscopy |
| url | https://www.mdpi.com/2073-4360/16/6/803 |
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