1993 Fiscal Year Final Research Report Summary
Non-destructive Detection of Surface Opening Defect Having Several Cross Sectional Shapes
| Project/Area Number |
04555179
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
溶接工学
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| Research Institution | KYUSHU INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
KATOH Mitsuaki Kyushu Institute of Technology, Faculty of Engineering, Professor, 工学部, 教授 (90039107)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIO Kazumasa Kyushu Institute of Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (50039145)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Magnetic testing / Radiographic testing / Ultrasonic testing / Convolution method / Contrastmeter / Density / Double crystal probe / Acoustic shield |
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| Research Abstract |
Magnetic testing, radiographic testing and ultrasonic testing were performed on the specimens of a steel and an aluminum alloy having several cross sectional shapes such as rectangular, circular, right-angled triangular and equilateral triangular shaped, which were machined by an electrospark machining. Main results obtained are as follows :
(1) Transfer functions were obtained using the convolution method, since we can obtain the output signal of magnetic test in which the shape of a flaw is converted through testing system. The unknown shape of a flaw could be approximately estimated by Fourier transformation of wave form obtained with a Hall generator. (2) In radiographic testing, we adopted the contrastmeter as the standard for eveluating the image on X-ray film and introduced the calculation equations for obtaining density of transmission photograph of the contrastmeter. Then, we could estimate the height of a defect by measuring density distribution due to the defect when we take a photograph both the contrastmeter and the specimen including the defect.
(3) In ultrasonic testing, we could approximately estimate the shape and dimensions of a flaw by using a double crystal probe. When acoustic shield is perpendicular to the longitudinal direction of a flaw, we can easily obtain high echo from the flaw.
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