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Measurement of Shape of Three-Dimensional Surface Crack by A. C. Electric Potential CT Method Using Frequency Information

Research Project

Project/Area Number 01460091
Research Category

Grant-in-Aid for General Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 機械材料工学
Research InstitutionOsaka University

Principal Investigator

KUBO Shiro  Osaka University, Faculty of Engineering, Professor, 工学部, 教授 (20107139)

Co-Investigator(Kenkyū-buntansha) NAKAI Yoshikazu  Kobe University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (90155656)
OHJI Kiyotsugu  Osaka University, Faculty of Engineering, Professor, 工学部, 教授 (20028939)
Project Period (FY) 1989 – 1991
Project Status Completed (Fiscal Year 1991)
Budget Amount *help
¥4,900,000 (Direct Cost: ¥4,900,000)
Fiscal Year 1991: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1990: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1989: ¥2,800,000 (Direct Cost: ¥2,800,000)
KeywordsNon-Destructive Inspection / Electric Potential Method / Surface Crack / Computed Tomography / Inverse Analysis / Fracture Mechanics / Boundary Element Method / Pipe
Research Abstract

The D. C. electric potential CT (computed tomography) method was extended to measurement of shape of a surface crack from A. C. potential readings. The main results obtained are summarized as follows.
1. Finite element formulation and programming were made for calculating electromagnetic fields in a two-dimensional body under A. C. application, assuming that the fields were stationary and using complex variable representation of filed quantities. The measured A. C. potential distribution agreed fairly well with the calculated distribution.
2. Boundary element formulations were made for calculating three-dimensional electromagnetic fields under very low frequency and very high frequency, and boundary element programming was made. A. C. electric potential in a plate with a surface crack was calculated. An inversion scheme based on the least residual method was developed for estimating the shape of surface crack from several A. C. potential readings. Numerical simulations showed that the estimated crack shape agreed fairly well with the given ones when potential readings had 2 significant digits. The estimated crack shape agreed well potential readings with 3 significant digits were used.
4. Measurement of A. C. potential were made for ferromagnetic and paramagnetic plates with a surface crack. Measured potential readings were used to estimate the crack shape based on the inversion scheme. It was found that fairly good estimation of crack shape can be made, although there remained technical problems unresolved in measuring A. C. potential distribution under high frequencies.
5. Applicability of the optimization techniques in estimating crack shape, location and size based on the least residual method was examined. A hierarchical procedure in the estimation was proposed and was found useful in the estimation. Selection of variables of optimization was also found to be important in attaining efficient estimation.

Report

(4 results)
  • 1991 Annual Research Report   Final Research Report Summary
  • 1990 Annual Research Report
  • 1989 Annual Research Report
  • Research Products

    (23 results)

All Other

All Publications (23 results)

  • [Publications] 大路 清嗣: "交流電気ポテンシャル情報を用いた表面き裂形状の同定" 日本機械学会講演論文集. No.924ー1. 148-150 (1992)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] 大路 清嗣: "電気ポテンシャルCT法によるパイプ外面からの内面き裂の測定" 日本機械学会講演論文集. No.924ー1. 151-153 (1992)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] 久保 司郎: "デ-タベ-スを用いた電気ポテンシャルCT法による表面き裂の位置および形状の測定" 第41回応用力学連合講演会講演予稿集. 165-166 (1992)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] S.Kubo: "Requirements for Uniqueness of Crack Identification from Electric Potential Distributions" ICM-90 Satellite Conf.Proc.,Inverse Problems in Engineering Sciences. 52-58 (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] S.Kubo: "Identification of a Surface Crack in a Pipe Using Data Base of Electric Potential Distribution" Mechanical Behaviour of Materials-VI. Vo1.4. 717-722 (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] 久保 司郎: "交流電気ポテンシャル法によるき裂長さ測定に対する数値的較正関係作成の試み" 日本機械学会講演論文集. No.900ー59. 517-519 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] OHJI, Kiyotsugu: ""Identification of a Surface Crack Using A. C. Potential Information"" Preprint of Japan Soc. Mech. Eng.No. 924-1. 148-150 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] OHJI, Kiyotsugu: ""Measurement of an Inner Surface Crack from Electric Potential Distribution on Outer Surface of a Pipe by the Electric Potential CT Method"" Preprint of Japan Soc. Mech. Eng.No. 924-1. 151-153 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] KUBO, Shiro: ""Measurement of Location and Shape of a surface Crack by the Electric Potential CT Method"" Preprint of 41st Japan Nat. Congr. Appl. Mech.165-166 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] KUBO, Shiro: ""Requirements for Uniqueness of Crack Identification from Electric Potential Distributions"" ICM-90 Satellite Conf. Symp. Inverse Problems in Engineering Sciences. 52-58 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] KUBO, Shiro: ""Identification of a Surface Crack in a Pipe Using Data Base of Electric Potential Distributions"" Mechanical Behavior of Materials -VI. 4. 717-722 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] KUBO, Shiro: ""A Numerical Calibration for Crack Measurement by A. C. Potential Method"" Preprint of Japan Soc. Mech. Eng.No. 900-59. 517-519 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] 大路 清嗣: "交流電気ポテンシャル情報を用いた表面き裂形状の同定" 日本機械学会関西支部第67期定時総会講演会講演論文集. 924ー1. (1992)

    • Related Report
      1991 Annual Research Report
  • [Publications] 大路 清嗣: "電気ポテンシャルCT法によるパイプ外面からの内面き裂の測定" 日本機械学会関西支部第67期定時総会講演会講演論文集. 924ー1. (1992)

    • Related Report
      1991 Annual Research Report
  • [Publications] 久保 司郎: "デ-タベ-タを用いた電気ポテンシャルCT法による表面き裂の位置および形状の測定" 第41回応用力学連合講演会講演予稿集. 165-166 (1992)

    • Related Report
      1991 Annual Research Report
  • [Publications] S.Kubo: "Requirements for Uniqueness of Crack Identification from Electric Potential Distributions" ICMー90 Satellite Conf.Proc.,Inverse Problems in Engineering Sciences. 52-58 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] 大路 清嗣: "電気ポテンシャル分布デ-タベ-スを用いた表面き裂の測定" 日本機械学会論文集(A編). 57. 2078-2084 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] S.Kubo: "Identification of a Surface Crack in a Pipe Using Data Base of Electric Potential Distribution" Mechanical Behaviour of MaterialsーVI. 4. 717-722 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] 久保 司郎: "逆問題のコンピュ-タアナリシス第1章,第4章" コロナ社, 30 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] 久保 司郎: "交流電気ポテンシャル法によるき裂長さ測定に対する数値的較正関係作成の試み" 日本機械学会講演論文集. No.900ー59. 517-519 (1990)

    • Related Report
      1990 Annual Research Report
  • [Publications] 久保 司郎: "電気ポテンシャルCT法による2次元内部き裂同定に対する最適化手法の適用" 日本機械学会講演論文集. No.900ー59. 526-528 (1990)

    • Related Report
      1990 Annual Research Report
  • [Publications] 久保 司郎: "電気ポテンシャルCT法に対する階層化された最適化手順の適用の提案とそれによる3次元表面き裂の同定" 日本機械学会講演論文集. No.900ー86. 667-669 (1990)

    • Related Report
      1990 Annual Research Report
  • [Publications] 久保司郎: "交流電気ポテンシャル法によるき裂測定に対する数値的較正(仮題)" 日本機械学会第68期全国大会講演会講演概要集. (1990)

    • Related Report
      1989 Annual Research Report

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Published: 1989-04-01   Modified: 2016-04-21  

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