| Project/Area Number |
18K04172
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 21030:Measurement engineering-related
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| Research Institution | Saga University |
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Principal Investigator |
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2020: ¥130,000 (Direct Cost: ¥100,000、Indirect Cost: ¥30,000)
Fiscal Year 2019: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
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| Keywords | 超音波撮像 / 点波源拘束偏微分方程式 / 波動情報処理 / 非破壊検査 / 異方性弾性体 / ガイド波 / 超音波試験 / ダイバージェンス / CFRP / 超音波計測 / コーシーの積分定理 / 光音響計測 |
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| Outline of Final Research Achievements |
Guided elastic waves are used for the non-destructive evaluation of plate-like structures. In recent years, manufacturing based on composites has increased gradually. However, the elastic wave dynamics in such materials is considerably more complicated. The conventional time-of-flight technique is not reliable for locating the defects even in isotropic plates because of the dispersiveness in the Lamb wave propagation. Avoiding difficulties caused by the dispersiveness, this paper proposes a novel imaging method based on the point-source constrained partial differential equation in order to reconstruct the silhouette image of the subsurface defects. A theoretical analysis of the proposed method is developed for single point-like defect in the isotropic plate. Numerical evaluation and several experimental results are presented to verify the image reconstruction process of the subsurface defects in the CFRP plates.
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| Academic Significance and Societal Importance of the Research Achievements |
近年, 複合薄板材料が様々な構造物において利用されている.その中でも炭素繊維強化樹脂薄板は軽量化と強度が求められる部材に多く使用されつつある. 多層繊維強化複合材では枚数や配向の違いによって弾性率(テンソル量)が変化するため, 均質な等方性弾性体の場合と比較して精密な欠損像の再構成が困難であった. 本研究は, 点波源拘束偏微分方程式を用いることにより, 超音波非破壊検査とは全く異なる原理にもとづき,波長や音速に左右されずに板材中の欠損位置を特定できる画期的な方法である.
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