Reliability Evaluation of small Specimen by Laser AE System
| Project/Area Number |
15360364
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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 |
Structural/Functional materials
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| Research Institution | The University of Tokyo |
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Principal Investigator |
ENOKI Manabu The University of Tokyo, Graduate School of Engineering, Associate Professor, 大学院・工学系研究科, 助教授 (70201960)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥15,100,000 (Direct Cost: ¥15,100,000)
Fiscal Year 2005: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2004: ¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 2003: ¥6,000,000 (Direct Cost: ¥6,000,000)
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| Keywords | Acoustic emission / Laser interferometer / Micro fracture / Small specimen / Non-destructive / アコースティック・エミッシ |
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| Research Abstract |
The objective of this research project is to improve the laser based AE (acoustic emission) technique by theoretical consideration and its application and demonstrate the effectiveness of this method for reliability evaluation. Research target was clearly focused by analyzing the advantages and weak points of conventional nondestructive evaluation (NDE) method and AE technique. Although here are some problems in the conventional AE method using PZT elements concerning adhesion of sensor, AE measuring technique using laser interferometer has some advantages such as absolute measurement of surface velocity, NDE in severe environment and so on. This technique was applied to the evaluation of dielectric breakdown process of thin dielectric film, and it was demonstrated that fracture morphology was classified by generation electric field value and frequency and precursor current was not due to phase transition and microfracture. Small partial discharge was successfully detected as AE signal
… More
by this method directly in liquid. Thermal deformation process in active composite materials was investigated and it was clearly shown that the cause of non-linearity of operating characteristics was due to microfracture induced by thermal stress. Also temperature range where damage was introduced was evaluated. Wavelet analysis of AE was used to understand the fracture process these composites. This method was also applied to thin metallic films with thickness of several tens micron and AE signals of these samples due to deformation and damage were successfully detected. This laser AE technique was applied to materials processing and reliability of materials was evaluated by in-process monitoring. Sintering of ceramics was monitored by laser AE technique and microcracks generated over 1500℃ were measured. These results were obtained by this unique laser AE technique and it was demonstrated that this technique was very useful for understanding of the fracture behavior and design of materials processing. Less
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Report
(4 results)
Research Products
(23 results)
