2005 Fiscal Year Final Research Report Summary
Development of smart composites using SiC fibers with a controlled surface
| Project/Area Number |
15360456
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Aerospace engineering
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| Research Institution | Japan Aerospace Exploration Agency (JAXA) |
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Principal Investigator |
OGASAWARA Toshio Japan Aerospace Exploration Agency (JAXA), Institute of Aerospace Technology, Senior researcher, 総合技術研究本部複合材技術開発センター, 主幹研究員 (20344244)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Composite / Health monitoring / SiC fiber / Functional surface / Damage |
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| Research Abstract |
A new sensitive strain monitoring composite as compared with carbon fiber reinforced composites (CFRP) was developed by applying SiC fibers with controlled surfaces. Carbon fibers in CFRP can be used as sensors to detect fiber fracture and strain of composites using electrical resistance change. However, even though the fibers were broken, the electrical resistance change is slight because of the electrical conduction between neighboring fibers.
In this study, surface oxidized SiC fibers with nano-scale thickness were applied to prevent electrical contacts between neighboring fibers. Model specimens were fabricated by embedding as-received or oxidized SiC fibers into epoxy resin, and electrical changes were measured under monotonic and loading-unloading tensile tests. The results obtained are summarized as follows;
(1)Electrical resistance of the fibers increased with increasing of applied strain in tensile tests of model specimens. Good reproducibility was obtained in electrical resistance change. Strain can be detected using SiC fibers.
(2)The specimens with the surface oxidized fibers exhibited much higher sensitivity in strain detection than those with the as-received fibers. Using the surface insulated fibers, electrical conduction due to contacts between neighboring fibers was effectively prevented.
(3)Electrical resistance change became low at unloading state because of contacts of fractured fibers with the decreasing applied strain.
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