Evalution of Interlaminar Fracture Strength by Moire Interferometry
| Project/Area Number |
05650085
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
ARAKAWA Kazuo KYUSHU UNIVERSITY Research Institute for Applied mechanics, Associate Professor, 応用力学研究所, 助教授 (00151150)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1993: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Composite Materials / Fracture / CFRP / Interlaminar Fracture / DCB Specimen / Crack Opening Displacement / Fracture Toughness / Moire Interferometry / 破壊靭性 |
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| Research Abstract |
Moire interferometry was utilized to study mode I interlaminar fracture in double cantilever beam (DCB) specimens of unidirectional carbon fiber/epoxy composites. The crack opening displacement (COD) was experimentally determined in the vicinity of the crack tip to evaluate the distortion at the beam root of the specimen. The beam root distortion was found to make an important contribution to increasing the value of COD.The effect of the beam root distortion on the evaluation of fracture toughness (G_I) value was also examined.
An improved analytical model was introduced to study COD,G_I, and compliance (C) as a function of the material stiffness (lambda) ahead of the crack front. The COD solution was derived and compared with the COD profiles near the crack tip measured by moire interferometry. Results showed that the COD solution can predict all the important qualitative features of the measured COD profiles ; also, the quantitative agreement at the loading point was very good. It was found that lambda plays an important role in evaluating the values of COD,C and G_I.
To study interlaminar deformation in DCB specimens of carbon fiber/epoxy composites, the values of COD determined by moire interferometry was compared with the analytical model. Estimations were made on the interlaminar tensile modulus and strain distribution ahead of the crack front. The results showed that the size of strain distribution was dependent on both the modulus and thickness of the specimens. Also there existed a specific correlation between the modulus and strain at the crack tip.
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Report
(3 results)
Research Products
(17 results)
