| Project/Area Number |
06555024
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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 | 試験 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Tohoku University |
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Principal Investigator |
SAKA Masumi Tohoku University, Faculty of Engineering, Professor, 工学部, 教授 (20158918)
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| Co-Investigator(Kenkyū-buntansha) |
KOMURA Ichirou Toshiba Corporation, Heavy Apparatus Engineering Laboratory, Chief Researcher, 重電技術研究所 金属材料・強度技術開発部, 主幹
ABE Hiroyuki Tohoku University, President, 総長 (00005266)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 1996: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1995: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1994: ¥3,200,000 (Direct Cost: ¥3,200,000)
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| Keywords | Nondestructive Evaluation / Closed Crack / Ultrasonic Inspection / Inverse Problem / Fatigue Crack / Simplefied Evaluation / Back Wall Echo / Automatic Measurement |
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| Research Abstract |
1.In order to establish a high accuracy and high speed sampling method by using an automatic two dimensional scanning for an amplitude of echo from crack, water and an ultrasonic equipment were used as medium for ultrasonic wave propagation and sampling of wave date. The data was installed in a digital oscilloscope which has a high sampling speed.
2.An evaluation equation which was simplified from a theoretical equation of a closed crack was derived. The evaluation method and a program of a computer to get a length of crack and a relative insensitivity of crack closure was shown by analyzing an inverse problem using the simplified evaluation equation.
3.In a quest to develop an improved detection and signal processing scheme, a new experimental study of a single probe ultrasonic technique concerning a beam angle has been conducted in an attempt to achieve better characteristic response of ultrasonics.
4.A high sensitive and automatic sampling system applied for crack echo data with oblique angle was developed from the automatic system using normal incident ultrasonics.
5.The relation between the oblique angle of ultrasonic incident beam and the reflection of the wave and also mode conversion were examined experimentally. The possibility of a nondestructive evaluation by ultrasonics with oblique angle was shown.
6.Two simulated small cracks extremely narrow width, 0.1 mm-wide slit, having depths of 1 and 3mm, wer evaluated by using oblique incident ultrasonics. The method can be applied for an evaluation of small cracks.
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