한국전산구조공학회논문집 (Journal of the Computational Structural Engineering Institute of Korea)

  • 제32권2호
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  • Pages.87-92
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  • 2019
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  • 1229-3059(pISSN)
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  • 2287-2302(eISSN)
한국전산구조공학회 (Computational Structural Engineering Institute of Korea)
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PSC 내부 텐던의 긴장력 관리를 위한 저전압 EM 센싱 기법

Low-Voltage EM(Elasto-Magnetic) Sensing Technique for Tensile Force Management of PSC(Prestressed Concrete) Internal Tendon

  • 박지환 (성균관대학교 미래도시융합공학과) ;
  • 김준경 (성균관대학교 미래도시융합공학과) ;
  • 엄기영 (한국철도기술연구원) ;
  • 박승희 (성균관대학교 미래도시융합공학과)
  • Park, Jihwan (Department of Convergence Engineering for Future City, Sungkyunkwan Univ.) ;
  • Kim, Junkyeong (Department of Convergence Engineering for Future City, Sungkyunkwan Univ.) ;
  • Eum, Ki-Young (Korea Railroad Research Institute) ;
  • Park, Seunghee (Department of Convergence Engineering for Future City, Sungkyunkwan Univ.)
  • 투고 : 2018.10.05
  • 심사 : 2019.01.07
  • 발행 : 2019.04.30
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초록

본 논문에서는 안정적인 전력공급이 어려운 실제 현장에 적용하기 위해서 PSC 내부 텐던의 긴장력 관리를 위한 저전압 EM센싱기법을 검증하였다. 지난 국내외 PSC 구조물 사고 사례를 볼 수 있듯이, 공용간 구조적 안정성을 확보하기 위해서는 PS텐던의 긴장력 관리가 매우 중요함을 알 수 있었다. 이에 본 논문에서는 EM센서를 통해 탄성-자기이론을 기반한 강자성체의 자기변형과 응력의 관계를 이용하여 전압 크기에 따른 긴장력에 대한 자기이력곡선을 계측하고자 하였다. 이를 위해 이중 원통코일형태의 EM센서를 제작하고 유압식 인장기를 이용한 PS텐던 인장 실험 장비를 구성하였다. 실험은 단계적으로 전압을 감소시켜 긴장력 크기에 따른 자기이력곡선의 변화를 계측하면서 최대/최소 전압값에 대한 계측결과에 따른 투자율의 변화와 긴장력의 관계를 비교 분석하였다. 그 결과, 전압이 감소하여 자기장의 크기가 작아짐에 따라 추정식에 대한 상수는 상이하지만 유사한 형태의 자기이력곡선 투자율의 변화를 확인할 수 있었다. 이를 통해 본 연구에서는 저전압 상태에서 EM센싱기법을 이용한 PSC 내부 텐던에 대한 긴장력 관리가 가능할 것으로 판단된다.

In this paper, we have verified a low-voltage EM(elasto-magnetic) sensing technique for tensile force management of PSC(prestressed concrete) internal tendon in order to apply the technique to actual construction sites where stable power supply is difficult. From observation of past domestic and overseas PSC structural accident cases, it was found that PS tension is very important to maintain structural stability. In this paper, we have tried to measure the tensile force from a magnetic hysteresis curve through EM sensors according to voltage value by using relation between magnetostriction and stress of ferromagnetic material based on elastic-magnetic theory. For this purpose, EM sensor of double cylindrical coil type was fabricated and tensile force test equipment for PS tendon using hydraulic tensioning device was constructed. The experiment was conducted to confirm relationship between changes of permeability and tensile force from the measurement results of the maximum / minimum voltage amount. The change of magnetic hysteresis curve with magnitude of tensile force was also measured by reducing amount of voltage step by step. As a result, the slope of estimation equation in accordance with magnitude of magnetic field decreases with the voltage reduction. But it was confirmed a similar pattern of change of magnetic permeability for the magnetic hysteresis loop. So, in this study, it is considered that it is possible to manage the tensions of PSC internal tendon using EM sensing technique in low-voltage state.

키워드

참고문헌

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