| Project/Area Number |
12555027
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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 | 展開研究 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Osaka University |
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Principal Investigator |
SAKAGAMI Takahide Osaka University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (50192589)
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| Co-Investigator(Kenkyū-buntansha) |
TERADA Hiroyuki National Aerosp ace Laboratory, Researcher, 構造材料総合研究グループ, 企画調整室・室長(研究者)
IOKA Seiji Osaka University, Graduate School of Engineering, Research Associate, 大学院・工学研究科, 助手 (50283726)
KUBO Shiro Osaka University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (20107139)
HATTORI Toshio Hitachi, Ltd. Researcher, 機械研究所, 主管研究員
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥12,900,000 (Direct Cost: ¥12,900,000)
Fiscal Year 2002: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2001: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2000: ¥8,100,000 (Direct Cost: ¥8,100,000)
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| Keywords | Quantitative NDT / Infrared Thermography / Thermal Wave Response / Lock-in Measurement / Aerospace Structure / Material Loss / Impact Delamination Damage / 非破壊検査 / ロックイン赤外線サーモグラフィ / 熱波動 / 航空機構造 / き裂 / 剥離 |
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| Research Abstract |
The present project developed a new quantitative nondestructive testing (NDT) technique for structural integrity assessment of aging aircrafts. The results obtained are summarized as follows.
1. For detecting cracks, singular electrothermal field near crack tips under the application of periodically modulated electric current was measured using lock-in thermography. Experimental investigations were made on the resolution and the applicability in the identification of cracks embedded in steel and aluminum alloy plates. Significant singular electrothermal field was observed at the crack tip in die lock-in thermal image. Location and size of the crack were accurately determined, demonstrating the feasibility of the proposed technique.
2. For material loss defects and delamination defects, a thermographic NDT technique based on the lock-in measurement of the surface temperature under periodical heating was developed. Experimental study was made on the applicability to the detection of flat b
… More
ottom hole defects and delamination defects. In-phase and out-of-phase temperature amplitude images were taken by the lock-in thermography, synchronized to the reference signal of the periodical heating. Further, another thermographic NDT technique based on the transient temperature under the pulse heating was developed. Temperature descent curve which reflects defect parameters such as size, shape and depth of defects was analyzed using Fourier series. Developed techniques were applied to the identification of material loss defects and delamination defects in aerospace structures. It was found that defect parameters can be accurately determined by the developed thermographic NDT techniques.
3. Quantitative NDT technique for delamination defects in concrete structures was developed based on the phase delay measurement using a lock-in infrared thermography. Location and size of the defect can be estimated from the contrast change and depth can be estimated from the relationship between phase delay and heating period.
4. Passive electric potential CT method was developed as a new monitoring technique. Electric potential distribution measurement on the surface of piezoelectric film glued on the structure was processed by inverse analysis. Less
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