• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Development of Electromagnetic Acoustic Transducers for Degradation Evaluation of FRP

Research Project

Project/Area Number 12650092
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Materials/Mechanics of materials
Research InstitutionOsaka City University

Principal Investigator

YAMASAKI Tomohiro  Osaka City University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (80230382)

Co-Investigator(Kenkyū-buntansha) MOTOGI Shinya  Osaka City University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (40221626)
Project Period (FY) 2000 – 2001
Project Status Completed (Fiscal Year 2001)
Budget Amount *help
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2001: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2000: ¥2,900,000 (Direct Cost: ¥2,900,000)
KeywordsComposite Material / Ultrasonics / Sensor / Delamination
Research Abstract

Electromagnetic acoustic transducer (EMAT) was developed for glass fiber reinforced plastics (GFRP). Delamination is one of the defects in FRP laminates, which lowers the compressive strength. Thus the nondestructive evaluation is necessary in order to assure the structural safety. For metals, the EMAT is already applied in the nondestructive inspection. The EMAT consists of a coil and magnets, and it can generate and detect the ultrasonic wave without any couplant between transducer and the metal using the Lorentz force or magnetostriction. However, since the GFRP is nonconductive, the EMAT for metals cannot be applied. In this study, we suggested to embed a coil in the prepreg stacking and to compose the EMAT with a magnet on the coil.
First, we ensured that the EMAT can transmit and receive the bulk shear wave, using the conventional piezoelectric transducer. We also found that the measurement of bulk wave by EMATs in pitch-catch mode is impossible because of the induction current. Then we switched to measure the guided SH wave velocity using two coils aligned in a line. The guided SH wave signal was extracted from leakage of the excitation signal by taking difference of two signals obtained for reversed magnetic fields. Accuracy of the velocity measurement was examined using the square plate specimen.
We also proposed the detection of delamination in GFRP laminates using the velocity of Lamb wave. Meander line coil was used, pitch of which is adjusted to the wavelength of the lowest symmetric mode Lamb wave. It was found that the transmitter coil should be embedded in the medial interlayer to obtain the good detectability. We revealed that the position of the delamination can be evaluated if the change in the slope between path length and transit time is detected accurately.

Report

(3 results)
  • 2001 Annual Research Report   Final Research Report Summary
  • 2000 Annual Research Report
  • Research Products

    (7 results)

All Other

All Publications (7 results)

  • [Publications] 山崎友裕: "非導電性FRP用電磁超音波センサの開発"非破壊検査. 51(1). 32-38 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Tomohiro YAMASAKI: "Electromagnetic Acoustic Transducer for Nonconductive FRP"Proc. of the 2nd Asian-Australasian Conf. on Composite Materials. 811-816 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Tomohiro YAMASAKI: "Electromagnetic Acoustic Transducers for Nonconductive FRP"Journal of the Japanese Society for Nondestructive lnspection. 51(1). 32-38 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Tomohiro YAMASAKI: "Electromagnetic Acoustic Transducers for Nonconductive FRP"Proc. of the 2nd Asian-Australasian Conf. on Composite Materials. 811-816 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] 山崎友裕: "非導電性FRP用電磁超音波センサの開発"非破壊検査. 51(1). 32-38 (2002)

    • Related Report
      2001 Annual Research Report
  • [Publications] Tomohiro Yamasaki: "Electromagnetic Acoustic Transducer for Nonconductive FRP"Proc. of the 2nd Asian-Australasian Conf. on Composite Materials. 811-816 (2000)

    • Related Report
      2001 Annual Research Report
  • [Publications] Tomohiro Yamasaki: "Electromagnetic Acoustic Transducer for Nonconductive FRP"Proc.of the 2^<nd> Asian-Australasian Conf.on Composite Materials. 811-816 (2000)

    • Related Report
      2000 Annual Research Report

URL: 

Published: 2000-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi