건축구조물스마트모니터링용 광섬유센서 2007. 1. 30. 김기수 홍익대학교
Outline 서론 ( 스마트구조물과광섬유센서 ) 광섬유와광케이블 광섬유 Bragg Grating 센서 보 - 기둥접합부의모니터링 섬유시트보강구조물의모니터링 원자력격납구조물의구조계측 터널에서의광섬유센서이용 교량및기타구조물에서의 FBG 사용예
www. ices.co.kr 서론 ( 스마트구조물과광섬유센서 )
성수대교및삼풍백화점, 미국국제무역센터붕괴사고 인명피해 1994 년 10 월 21 일 사망 32 명, 부상 17 명 직접손실비용 : 700 억원 간접손실비용 : 1 조원 1995 년 6 월 29 일 인명피해사망 502 명, 부상 937 명실종 6 명 직접손실비용 : 2700 억원 동산 1200 억부동산 1500 억 2001 년 9 월 11 일 인명피해사망 2823 명 직접손실비용 : 160 억달러 인명손실, 부상비용 50 억달러
통신기술의발달 Communication Technology 1870 1900 1960 1970 2000 유선통신 무선통신 이동통신 ( PCS, CDMA, TRS 등 ) 위성통신 광통신 ( TDM, WDM, DWDM 등 )
센서기술의발달 Sensor Technology 1920 1940 1960 1980 1990 2000 가스센서 레벨센서 자기센서 온도센서 바이오센서 광센서 압력센서 광섬유센서
구조물의첨단화 : Smart Structure 외부하중과구조내부의변화를감지하고, 평가하여, 살아있는생물처럼외부자극에스스로대응하는기능을가진구조 내용 스마트센서 : 광섬유센서, 압전센서, 기타기능성센서 액추에이터 : 압전액추에이터, 형상기억합금, 자왜재료 스마트재료 = 재료 + 스마트센서 (+ 액추에이터 )
Smart Structure 의특성 내 외부의변화에대한감지, 평가, 대응기능을지닌구조물 구조물의건전도가지속적으로파악되는구조물 보수 / 보강의필요성이효과적으로파악되는구조물 과다하중에대해능동적으로대처하는구조물 사용연한 (Life Cycle) 동안사용성과경제성의극대화를위한종합적인계획, 설계, 시공및유지관리
스마트재료의최적의해법 - 광섬유센서 Main-system Sub-system Internet Modem 센서와 Sub-System 간의통신이가장큰문제이후는디지털신호로취급이용이 일체화후무선방식 : 전원필요, 부피증가, Data 전송거리의한계 광통신을적용한광섬유센서 : 소형, 원거리신호전달용이 인체의감각, 신경계와흡사 최적
광섬유센서의장점 크기가작고, 내구성이우수재료에삽입되거나일체화가용이함. 주성분이유리재질부식에강하고, 전자기파에의한잡음 (noise) 발생없음. 한가닥에여러개의센서를배열하여다중송신 (multiplexing) 가능무게의감소, 구조물에서의연결부최소화 파장값의변화를측정하므로절대값의측정가능 광통신및광전자산업의발전점차저렴한가격, 고성능의광섬유센서를보다쉽게적용가능 기존의센서에비해토목건축구조물용으로아주적합
외부자극에따른구조물거동과스마트광섬유센서 Response 외부자극 온도변화 습도변화 풍하중 차량통과 지진 선박에의한충돌 부식 Crack 발생및진전 구조물의변화 광섬유센서신호의변화 Visual 한 Display 건전성평가수명예측
광섬유센서의활용 가. 교량, 대형구조물등의 On-Line Monitoring 시스템나. 차량의중량, 속도, 차종분류를위한 Intelligent Transportation System 다. 침입자감시용시스템라. 콘크리트구조물보수, 보강을위한 Smart 시스템마. 토목건축물시공시안전모니터링바. 우주항공용복합재료구조물의공정모니터링및사용중안전감시라. 의료및생체의진단분석
www. ices.co.kr 광섬유와광케이블
광섬유의구조및특징 Transparent Glass Fiber Optical Medium Small Loss Long Distance Propagation No Electromagnetic Interference Small Noise Higher Frequency Than Electromagnetic Wave More Information Transmission Optic Fiber Light Cladding Core
Cabling Cabling 의기본요건 다루기쉽다. 광학특성을손상시키지않으면서기계적특성을강화시켜야한다. 케이블을제작하는동안에미소구부림이최소화되고, 그이후에도일어날가능성이제한되도록설계하여야한다. 고려항목 장력 (tensile strength) 분쇄저항 (crush resistance) 과도한구부림에서보호 (protection from excess bending) 내마모성 (abrasion protection) 진동차단 (vibration isolation) 내습및내화학작용 (moisture and chemical protection)
단일섬유케이블과다섬유케이블
OPGW (Optical Power Ground Wire: 광섬유복합가공지선 ) 현존하는설비를사용하기위해서이전에설비된공중접지선에광케이블을동여맬수있는데광섬유는전자파간섭의영향을받지않으므로전력선주위와잡음환경하에서통신하기에적합하기때문이다. 높은인장강도 응력과변형으로부터보호 습기및수소침투에대한양호한저항력 2~48심
유니튜브케이블 특징 코어수 2~12심 경량 작은직경 편리한설치 젤리충진재 : 방수젤리로충진된루즈튜브 인장선 : FRP, 아라미드얀또는강 / 연선 응용분야 고속음성, 비디오, 데이터전송 LAN 장거리네트워크 - 관로용, 직매용, 가공용, 옥내용
광섬유격자센서
Fiber Bragg Grating Sensors Source Light λ B Reflection Transmission Λ L λ B = 2nΛ Δλ B =λ B (1 P E )ε= λ B (α+ξ)δt Ge-doped Fiber Core n = Reflective Index Wavelength change is the function of strain and temperature
Production Method of FBG Λpm Incident UV Beam Dpm Silica Glass Phase Grating (Zero Order Suppressed) Optical Fiber -1 st Order Zero Order ( < 5% of throughout ) +1 st Order Λgrating
FBG vs Electric gauges Sensors in Railroad Bridge Logger closed to Electric Generator
FBG Sensor Packages Sensor Package Sensor Fixture for long gauge Sensor Package (4,6,8 cm Gauge Length) FBG Accelerometer FBG Package for strain measuement
FBG Sensor System (WDM method) Temperature controlled SLD source
FBG System Software Screen for Time Domain Screen for Wavelength Domain
보 - 기둥접합부에서의 광섬유센서모니터링
Preparation of Specimen
Test Set-Up
Fiber Sensors Installation
Input Load Profile 12 11 10 9 8 load (tonf) 7 6 5 4 3 2 1 0 21:21:28 21:39:28 21:47:28 21:55:34 22:03:34 22:11:34 22:19:34 22:27:34 time
Sensor Output 1 12 11 10 9 8 load (tonf) 7 6 5 4 3 2 1 0-1 -0.4-0.3-0.2-0.1 0 0.1 0.2 0.3 0.4 displacement (mm) LVDT 7 광섬유센서1
Sensor Output 3 12 11 10 9 8 load (tonf) 7 6 5 4 3 2 1 0-1 -0.9-0.8-0.7-0.6-0.5-0.4-0.3-0.2-0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 displacement (mm) LVDT 1 광섬유센서3
Sensor Output 4 1 0.8 0.6 displacement (mm) 0.4 0.2 0-0.2-0.4-0.6-0.8-1 21:34:04 21:38:04 21:42:04 21:46:04 21:50:04 21:54:10 21:58:10 22:02:10 time LVDT 3 광섬유센서 4
Input Load Profile load (tonf) 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0-0.2-0.4-0.6-0.8-1 -1.2-1.4-1.6 2:03:14 2:08:20 2:13:20 2:18:20 2:23:20 2:28:20 2:33:20 2:38:20 2:43:20 2:48:20 time
Sensor Output 3 0.16 0.12 0.08 displacement (mm 0.04 0-0.04-0.08-0.12 Potentio Meter 9-0.16 광섬유센서 3 2:03:14 2:08:20 2:13:20 2:18:20 2:23:20 2:28:20 2:33:20 2:38:20 2:43:20 2:48:20 time
섬유시트보강구조물의모니터링
Sheet type repairing materials Carbon fiber sheets and glass fiber sheets
Concept of the Development New Patch type Composite Repairing Materials Accumulated Outdated Structure (2-30 years ago, lots of construction during economic development in Korea) Safe for Corrosion, Lightweight, Easy Applying Process Rapid Expansion of Repairing and Retrofitting Materials New Monitoring Device : Fiber Optic Sensors Measurement of Absolute Strain Value + Durability and Long Term Stability Adequate for Monitoring System New Concept of Self Diagnostic Retrofitted Structure
Problems of Retrofitted Structures Brittle Fracture Separation of the Edge
SOLUTION Design: Optimal lay-up of composites Optimal orientations of fibers Construction : Standardization and Manual Durability : Estimation of deterioration with absolute values of strain Fracture Monitoring : Check brittle behavior and delamination with optical fiber sensor Optimization of Design Application of Fiber Sensors
Example of Self Diagnostic Retrofitted Structure Composite Patch Fiber Optic Sensor Connector
Experiment of Concrete Beam with Composite Patch Adherence of Composite Patch 4-point Bending Test
Design of Self Diagnostic Retrofitted Specimen 광섬유센서 광섬유센서 단위 : mm 광섬유센서상세 Strain Comparison between Concrete and Repairing Composite
Lay-up Design of the Commercial Composite Patches CONCRETE Adhesive Glass Fiber Sheet (Layer1) CONCRETE Adhesive Glass Fiber Sheet (Layer1) Glass Fiber Sheet (Layer2) Carbon Fiber Sheet (Layer2) GGO GCO GGO : Glass fiber + Glass fiber GCO : Glass fiber + Carbon fiber
Fiber Sensors in the Composite and in the Concrete 4000 GGO 7000 GCO 6000 3000 5000 Load (kgf) 2000 Load (Kgf) 4000 3000 1000 2000 1000 0 0 200 400 600 800 1000 1200 1400 1600 1800 Strain (Microstrain) 밑면 Composite 광섬유센서옆면 Concrete 광섬유센서 0 0 500 1000 1500 2000 2500 3000 Strain (Microstrain) 옆면 Composite 광섬유센서 밑면 Concrete 광섬유센서 Glass fiber + Glass fiber (GGO) Glass fiber + Carbon fiber (GCO)
Load(kgf) 3000 2500 2000 1500 1000 500 0 0 500 1000 1500 2000 2500 Microstrain Between Composite 탄소섬유보강재사이의광섬유 Concrete / Composite 콘크리트와탄소섬유사이의광섬유 Fiber sensors embedded in shear specimen Embedded fiber sensors show reasonable response to the loads. Embedded fiber sensors have potential to monitor peel out effect.
Monitoring the Specimen with Embedded Sensors Surface of the Sheet Inside of the Sheet 10 cm grib FBG sensor fiber sheet steel gage Embedded Optical Fiber Sensor between Layers Encapsulated with Thin Tube Overcome the warping of composites due to big size strain gauges and wires
Stain deference between repairing composites and concrete < Center of SG-3 > < Center of SN-3> < End part of SG-3 > < End part of SN-3 >
Fiber Optic Smart Monitoring of Nuclear Containment Structure
Structural Integrity Test Design Concept of the containment structure is blocking the radiation of the nuclear plant when the temperature and pressure increase rapidly. The structural response of the containment structure must be within 30% difference from predicted limits plus tolerances of the transducer when pressurized to 115% of containment design pressure (65.6 psig).
Installation of transducers Extensometer Installed Invar Wire Data during SIT and ILRT
Problems of displacement transducers Problems of transducer and wire Interference of Invar wires with inner structures Detachment of lug plate Malfunction of extensometers Lack of reliability of data Extensometer Necessity of new type reliable and multiplexed long gauge sensors Installed Invar Wire
FBG Sensors Easy to handle, good resolution
Installed FBG sensors in the Structure R5, R6, R7, R8 D1 T1,T2 V10, E3,4,9
Installation of Fiber Optic Sensors
Delivery of Optical Fiber Remote Controlled Balloon Plane
Pressurizing 13 big compressors
Fiber Bragg Grating System Applied to Containment Structure
Uljin Plant #6 T-1 0.25 0.2 0.15 0.1 Extensomter Calculated Allowed optical sensor 0.05 0 0 4.8 9.9 10 14.9 20.6 25 26 30.6 34.6 35.7 40.5 44.9 44.9 49.2 53.8 57 59.1 63.7 65.8 58.7 56.8 48.9 44.1 37.8 35.1 31.9 26.1 22.2 15.8 10 6.1 1.4 0 Displacement (inch) -0.05 Pressure (psig)
FBG Sensors Applied to Tunnels
진원장성구간 Tunnel
장수익산구간 Tunnel
대구지하철근접시공구간
대구지하철근접시공구간시스템화면
6K 985m( 종단면 ) 6K 685m( 종전체 )
교량구조물의광섬유센서모니터링
Bridge Applications - Sungsan Bridge a ) b ) c ) d) e ) f) a) to f) : 20 to 70 km/hr of 40 ton weigh dump truck each
Fiber Optic Smart Monitoring of Other Structures
Fatigue Tests 7000 Strain under Cyclic Loading Fatigue Specimen 6000 5000 4000 Strain gauge 3000 2000 Fiber sensor 1000 0 0 200 400 600 800 1000 1200 600 500 400 100K Cyclic Loading Fatigue Crack Micro Strain 300 200 100 0 0 500 1000 1500 2000 2500-100 Time Strain gage( 중앙부 ) Strain gage(1/4지점 ) Strain gage(1/4지점 ) FBG1(1/4 지점 ) FBG2( 중앙부 )
Weigh-In Motion Application 5 th Axle 1 st Axle 2 nd Axle 3 rd Axle 4 th Axle Oscilloscope display of A/D converter input part
Conclusions - FBG (Fiber Bragg Grating) sensors worked well on the various structures. - FBG sensor are easy to attach and handle. - Fiber can be delivered anywhere with balloon plane. - FBG sensor can be controlled by remote system - FBGs describe the structural behavior very well. - FBGs have potential to many other applications such as load cells, accelerometers and inclinometers.