1993 Fiscal Year Final Research Report Summary
Research of Evaluation of Small Change in Material Construction by Means of Electromagnetic Method
| Project/Area Number |
03805009
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
材料力学
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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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| Project Period (FY) |
1991 – 1993
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| Keywords | Nondestructive Evaluation / Inverse Problem / Computational Mechanics / Coating / Electroplating / Potential Drop Technique / Alternating Current / Electromagnetic Property |
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| Research Abstract |
The research has been performed to develop an electromagnetic method for evaluating nondestructively small change in material construction. The main results are summarized as follows :
1. The electromagnetic problems on a cylindrical conductor coated with a thin layr, the electromagnetic property of which is different, were treated. Such a conductor is modeling an electroplated material. The electromagnetic fields induced in the surface layr and the inner cylinder by AC current which uniformly flows along the longitudinal axis of the conductor were theoretically analyzed, and the AC potential drops on its surface were obtained. Furthermore, by considering the effect of the electromagnetic induction upon the AC potential drops measured actually, the electromotive force induced on potential measuring proves was included into the modified theoretical analysis of potential drops as the mutual inductance.
2. The AC potential drops on the surface of the cylinder coated with chromium electroplated for engineering purpose were measured, and the relation between the AC frequency and the AC potentioal drops was obtained.
3. The inverse problem analysis was proposed. In the analysis, coating thickness, the electromagnetic properties of the electroplated specimens and the mutual inductance are treated as unknowns. The theoretical AC potential drops computed are compared with the AC potential drops measured to determine the unknowns.
4. By the analysis, the coating thickness, the electromagnetic properties and the mutual inductance were evaluated. The results obtained from the evaluation showed that the present method is valid.
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