• 제목/요약/키워드: Bragg Grating Sensors

검색결과 207건 처리시간 0.04초

Planar Optical Waveguide Temperature Sensor Based on Etched Bragg Gratings Considering Nonlinear Thermo-optic Effect

  • Ahn, Kook-Chan;Lee, Sang-Mae;Jim S. Sirkis
    • Journal of Mechanical Science and Technology
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    • 제15권3호
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    • pp.309-319
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    • 2001
  • This paper demonstrates the development of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include design and fabrication of the etched planar waveguide Bragg grating optical temperature sensor. The typical bandwidth and reflectivity of the surface etched grating has been ∼0.2nm and ∼9%, respectively, at a wavelength of ∼1552nm. The temperature-induced wavelength change is found to be slightly non-linear over ∼200$^{\circ}C$ temperature range. Typically, the temperature-induced fractional Bragg wavelength shift measured in this experiment is 0.0132nm/$^{\circ}C$ with linear curve fit. Theoretical models with nonlinear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

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광섬유 브래그 격자를 이용한 촉각센서용 유연 단위 힘 센서 개발 (Development flexible force sensor using fiber bragg grating)

  • 허진석;김만섭;이정주
    • 센서학회지
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    • 제15권4호
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    • pp.251-256
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    • 2006
  • This paper describes the flexible force sensor using fiber Bragg grating (FBG) and silicone rubber for the tactile sensation to detect the distributed normal force. The newly designed FBG flexible force has simple structure and can be easily multiplexed with simple wiring compared with the other electric mechanical sensors. We designed the flexible silicone rubber transducer and found the optimum embedding position of FBG in the transducer using the finite element analysis. This flexible force sensor has good performance and is immunity to the electromagnetic field compared with any other kinds of small force sensors for tactile sensation.

Health monitoring of carbon fiber-reinforced polymer composites in γ-radiation environment using embedded fiber Bragg grating sensors

  • Jing Zhong;Feida Chen;Yuehao Rui;Yong Li;Xiaobin Tang
    • Nuclear Engineering and Technology
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    • 제55권8호
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    • pp.3039-3045
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    • 2023
  • Fiber-reinforced polymer (FRP) composites are considered suitable candidates for structural materials of spacecrafts due to their excellent properties of high strength, light weight, and corrosion resistance. An online health monitoring method for FRP composites must be applied to space structures. However, the application of existing health monitoring methods to space structures is limited due to the harsh space environment. Here, carbon fiber-reinforced polymer (CFRP) composites embedded with fiber Bragg grating (FBG) sensors were prepared to explore the feasibility of strain monitoring using embedded FBG sensors in γ-radiation environment. The analysis of the influence of radiation on the strain monitoring demonstrated that the embedded FBG can be successfully applied to the health monitoring of FRP composites in radiation environment.

Evanescent Wave-Based Fiber Bragg Grating Biosensors

  • Lee, Sang-Mae;Kim, Deug;Dagenais, Mario;Chryssis, Athanasios N.;Saini, Simarjeet Singh;Yi, Hyunmin;Bentley, William E.
    • 한국광학회:학술대회논문집
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    • 한국광학회 2006년도 하계학술발표회 논문집
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    • pp.399-400
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    • 2006
  • Etched fiber Bragg grating, Sensitivity of fiber-Bragg-grating sensors to index of surrounding, Hybridization of DNA

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광섬유 브래그 격자 센서를 활용한 재킷식 해양구조물의 손상 감지 기법 개발 (Development of a Damage Monitoring Technique for Jacket-type Offshore Structures using Fiber Bragg Grating Sensors)

  • 박현준;구기영;이진학;윤정방
    • 대한토목학회논문집
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    • 제31권6A호
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    • pp.399-408
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    • 2011
  • 최근 스마트 센서를 활용한 구조물의 건전성 모니터링 및 손상 탐색 기법에 대한 연구가 활발히 진행되고 있다. 그 중에서도 광섬유 센서 중 하나인 FBG(fiber Bragg grating) 센서는 경량이고, 내구성이 좋으며, 전자기적 영향이 없을 뿐 아니라 한 가닥으로 여러 지점에서의 계측이 가능한 장점을 가지고 있어 많은 연구와 적용이 시도되고 있다. 이 논문에서는 이러한 FBG 센서를 활용하여 재킷식 해양구조물에 발생하는 손상을 탐색하는 연구를 수행하였으며, 특히 구조물에서 계측된 자료로부터 여러 환경요인을 제거하고 보다 손상에 민감한 특성을 보기 위하여 주성분 분석 기법 적용에 관한 연구를 중점적으로 수행하였다. 제안한 방법의 검증을 위하여 시험조류발전소 구조물의 축소 모델을 활용하여 하중 및 온도 등의 외부 환경이 다른 조건에서 실내 실험을 수행하였고, 이로부터 본 논문에서 제안한 방법이 외부 환경의 영향을 최소화하여 보다 손상을 민감하게 탐색함을 확인하였다.

Strain Transmission Characteristics of Packaged Fiber Bragg Grating Sensors for Structural Health Monitoring

  • Cho, Sung-In;Yoo, Seung-Jae;Kim, Eun-Ho;Lee, In;Kwon, Il-Bum;Yoon, Dong-Jin
    • 비파괴검사학회지
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    • 제30권3호
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    • pp.236-243
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    • 2010
  • Fiber Bragg grating(FBG) sensor arrays can be used to monitor the mechanical behavior of the large composite structures such as wind turbine rotor blades and aircrafts. However, brittle FBG sensors, especially multiplexed FBG sensors are easily damaged when they are installed in the flexible structures. As a protection of brittle FBG sensors, epoxy packaged FBG sensors have been presented in this paper. Finite element analysis and experiments were performed to evaluate the effects of adhesives, packaging materials and the bonding layer thickness on the strain transmission. Two types of epoxy were used for packaging FBG sensors and the sensor probes were attached with various bonding layer thickness. It was observed that thin bonding layer with high elastic modulus ratio of the adhesive to packaging provided good strain transmission. However, the strain transmission was significantly decreased when elastic modulus of the adhesive was much lower than the packaged FBG sensor probe's one.

해석적인 기법을 통한 FBG 센서의 스펙트럼 분석 및 수소고압용기의 센서 삽입위치 결정 (Spectrum analysis of the FBG sensor signal and location determination of FBG sensor into the $H_2$ pressure vessel)

  • 박상오;김철웅;박지상;김천곤
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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    • pp.25-28
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    • 2005
  • The optical fiber is known for the proper sensor which can accomplish the structural health monitoring, Fiber Bragg Grating sensors are being studied more than any other fiber optic sensors due to good multiplexing capabilities. But because the signal stability of FBG sensors can be influenced by the strain gradient, it needs to analyze signal of FBG sensors. Particularly acoording to strain gradient induced by structural geometry or cracks, the spectrum peak of the FBG sensor signal can be split easily. In this paper, the spectrum analysis of the FBG sensor signal was performed and the region of embedment of FBG sensors was determined in $H_2$ pressure vessel by numerical method.

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광섬유 격자 센서와 빔 커플러를 사용한 회전중인 블레이드의 변형률 측정 방법 (On-line Strain Measurement of Rotating Blade Using Fiber Bragg Grating Sensors and Beam Coupler)

  • 이인재;이종민;이상배;황요하
    • 한국소음진동공학회논문집
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    • 제16권11호
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    • pp.1172-1178
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    • 2006
  • Measurement of blade strain with sensors directly installed on the blade has one critical issue, how to send the sensor signal to the ground. Strain-gauges have been dominantly used to directly measure stress of a blade and either a slip ring or a telemetry system has to be used to send measured signal to the ground. However, both systems have many inherent problems and sometimes very severe limitations to be practically used. In this paper, new on-line strain monitoring method using. FBG(Fiber Bragg Grating) sensors and a beam coupler is introduced. Measurement of rotor stress using FBG sensors is nothing new, but unlike other system which installs all necessary instruments on the rotor and use telemetry system to send data to the ground, this system makes use of light's unique characteristic - light travels through space. In this new approach, single optical fiber with many FBG sensors is installed on the blade and all other necessary instruments can be installed at ground thereby giving tremendous advantages over slip ring or telemetry system. A reference sensor is also introduced to compensate the beam coupler's transmission loss change due to rotation. The suggested system's good performance is demonstrated with experiments.

광섬유 브래그 격자 센서의 고선량 방사선 효과 (High Total Dose Radiation Effects on Fiber Bragg Grating Sensors)

  • 김종열;이남호;정현규;김영웅;한원택
    • 한국정보통신학회논문지
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    • 제17권6호
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    • pp.1425-1431
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    • 2013
  • 게르마늄이 도핑된 실리카 코어에 페이즈 마스크를 이용하여 격자를 새긴 광섬유 브래그 격자 센서를 총 선량 23 kGy의 감마선을 조사하여 방사선에 의한 브래그 파장의 변화를 측정하였고, 방사선 조사 후에는 어닐링 특성을 평가하였다. 패키징된 FBG 센서의 경우, 방사선 조사동안 최대 91 pm의 브래그 파장변화가 나타났다. 또한 동일한 조건에서 패키징된 광섬유 브래그 격자 센서가 패키징 되지 않은 센서보다 방사선 민감도가 2배 이상 높게 나타났다.

스마트 구조물용 광섬유 격자센서의 원전격납건물 적용 실험 연구 (Study on the Fiber Bragg Grating Smart Sensors for Containment Structure in Nuclear Power Plant)

  • 김기수;송영철;방기성;윤덕중
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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    • pp.412-415
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    • 2004
  • This study was performed to verify the behaviors of fiber Bragg grating (FBG) sensors attached to the containment structure in the nuclear power plant as a part of structural integrity test which demonstrates that the structural response of the non-prototype primary containment structure is within predicted limits plus tolerances when pressurized to $115\%$ of containment design pressure, and that the containment does not sustain any structural damage.

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