CN102175170A - Detecting method and sensor for cracks of civil structure based on optical fiber long chirped grating frequency domain reflection technology - Google Patents
Detecting method and sensor for cracks of civil structure based on optical fiber long chirped grating frequency domain reflection technology Download PDFInfo
- Publication number
- CN102175170A CN102175170A CN2011100694292A CN201110069429A CN102175170A CN 102175170 A CN102175170 A CN 102175170A CN 2011100694292 A CN2011100694292 A CN 2011100694292A CN 201110069429 A CN201110069429 A CN 201110069429A CN 102175170 A CN102175170 A CN 102175170A
- Authority
- CN
- China
- Prior art keywords
- coupling mechanism
- optical fiber
- input end
- sensor
- chirp grating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Length Measuring Devices By Optical Means (AREA)
Abstract
The invention discloses a detecting method and a sensor for cracks of a civil structure based on an optical fiber long chirped grating frequency domain reflection technology. In the detecting method, a distributed optical fiber monitoring system is formed on the basis of the frequency domain analysis technology of optical fiber long chirped grating so as to realize the strain monitoring and crack positioning of a structure. Compared with the prior art, the invention has the advantages that spatial resolution is high, micrometer-grade spatial resolution can be realized, and the spatial positioning accuracy is high; the distributed detection of tiny cracks and damages of materials can be realized; the sensitivity is high, the system stability is good; in addition, the sensor has simple structure, low cost and high cost performance.
Description
Technical field
The present invention relates to a kind of frequency-domain analysis technology distributed fiber-optic monitoring system and implementation method thereof, can realize strain monitoring and location, crack structure based on the long chirp grating of optical fiber.
Background technology
Monitoring structural health conditions is to obtain inside configuration information by various lossless detection methods, and makes safety evaluatio and necessary early warning.The sensor that is used for monitoring structural health conditions at present mainly comprises foil gauge, optical fiber Bragg raster (FBG) sensor, and based on distributed fiberoptic sensor of Brillouin scattering etc.But research and engineering is actual shows because structure partial stress is concentrated and the crack occurs, can cause strain-ga(u)ge transducer to lose efficacy.And optical fiber FBG sensor can only be measured the Strain Distribution of series of discrete point, and can't obtain Global Information.The spatial resolution of Brillouin scattering Fibre Optical Sensor can only reach tens centimetres at most, is not enough to accurate detecting structure crack and accurate location information.In many engineering structures, often requirement can accurately be located crack position and damaged condition in very big measuring distance, to satisfy structural entity and local monitoring and evaluation simultaneously.This long-term health to large scale structure detects significant.
Summary of the invention
The purpose of this invention is to provide a kind of detection method that is used for the civil structure crackle and sensor based on the long chirp grating frequency domain of optical fiber reflection technology, be used for structure partial strain and crack detection, measuring distance is long, and stability and repeatability are good, the precision height.
Technical solution of the present invention is as follows:
A kind of detection method that is used for the civil structure crackle based on the long chirp grating frequency domain of optical fiber reflection technology, it is characterized in that: the frequency-domain analysis technology of utilizing the long chirp grating of optical fiber, form the distribution type fiber-optic monitoring system, realize structural strain monitoring and location, crack.
A kind of sensor that is used for the civil structure crackle based on the long chirp grating frequency domain of optical fiber reflection technology, it is characterized in that: comprise tunable laser, first coupling mechanism, second coupling mechanism, the 3rd coupling mechanism, the long chirp grating sensor of optical fiber, Polarization Controller, photodetector, data collecting card, signal analysis and disposal system, display device is formed, the output terminal of described light source connects the input end of first coupling mechanism, first coupling mechanism has two output terminals, first output terminal connects the first input end of the 3rd coupling mechanism by Polarization Controller, second output terminal of first coupling mechanism connects the first input end of second coupling mechanism successively, the input end of long chirp grating sensor, second input end of second coupling mechanism and second input end of the 3rd coupling mechanism, first output terminal of described second coupling mechanism is connected with the input end of described long chirp grating sensor, the output terminal of long chirp grating sensor connects second input end of second coupling mechanism, at the output terminal of the described coupling mechanism described photodetector of connecting successively, data collecting card, signal analysis and processing section and display device.
The present invention is a kind of frequency domain reflection sensing technology based on the long chirp grating of optical fiber, and its formation tunable laser, three coupling mechanism, the long chirp grating sensor of optical fiber, Polarization Controller, photodetector, data collecting card, signal analysis and disposal system, computers show and form.Its annexation is as follows: the broadband light that light source sends connects by optical fiber and is divided into two-way after entering coupling mechanism, and one road light enters coupling mechanism after by Polarization Controller, another road light by coupling mechanism and long chirp grating sensor after former road return, also enter coupling mechanism.Coupling mechanism output termination photodetector, data collecting card is gathered the output signal of photodetector, behind signal analysis and processing section, shows testing result on computers, with the reflected signal variation of the long chirp grating sensor of observation optical fiber.
Compared with prior art, the advantage that the present invention has: 1. high spatial resolution, can realize the micron dimension spatial resolution, the spatial positioning accuracy height; 2. can realize the distributed detection of material minute crack and damage; 3 is highly sensitive, and system stability is good, and sensor construction is simple, and cost is low, the cost performance height.
Description of drawings
Fig. 1 is a kind of concrete structure synoptic diagram of the present invention.
Fig. 2 is a kind of embodiment structural representation of the present invention.
Embodiment
Below in conjunction with accompanying drawing the present invention is elaborated, but should not limit protection scope of the present invention with this.
Embodiment one: specify present embodiment below in conjunction with Fig. 1,2.Tunable laser 1 is sent and is divided into two-way after the time dependent narrow-linewidth laser of wavelength is gone into coupling mechanism 2, after one road light passes through Polarization Controller 5 and coupling mechanism 4 as reference light, enter photodetector 7, another road enters long chirp grating sensor 6 backs by optical grating reflection as sense light through coupling mechanism 3.Reflected light enters coupling mechanism 4 by coupling mechanism 3, enters photodetector 7 then.The current signal that light signal is exported behind photodetector 7 is gathered by data collecting card 8, analyze by 9 pairs of signals of signal processing then, the long chirp grating reflected light signal of the optical fiber that obtains in the current signal being comprised changes, and is shown by computer 10 then.The length of long chirp grating 6 can be selected according to practical situations, 10 centimetres-1 meter of scope.Diverse location is put corresponding different wave length such as Fig. 2 shows in the length of long chirp grating, chirp grating can be made by phase mask plate or laser pointwise, so the step distance that the reflectance spectrum wavelength width of long chirp grating can be write by the pitch or the pointwise of phase mask plate determines.
Claims (2)
1. detection method that is used for the civil structure crackle based on the long chirp grating frequency domain of optical fiber reflection technology, it is characterized in that: the frequency-domain analysis technology of utilizing the long chirp grating of optical fiber, form the distribution type fiber-optic monitoring system, realize structural strain monitoring and location, crack.
2. sensor that is used for the described detection method of claim 1, it is characterized in that: comprise tunable laser (1), first coupling mechanism (2), second coupling mechanism (3), the 3rd coupling mechanism (4), the long chirp grating sensor of optical fiber (5), Polarization Controller (6), photodetector (7), data collecting card (8), signal analysis and disposal system (9), display device (10) is formed, the output terminal of described light source (1) connects the input end of first coupling mechanism (2), first coupling mechanism (2) has two output terminals, first output terminal connects the first input end of the 3rd coupling mechanism (4) by Polarization Controller (6), second output terminal of first coupling mechanism (2) connects the first input end of second coupling mechanism (3) successively, the input end of long chirp grating sensor (5), second input end of second input end of second coupling mechanism (3) and the 3rd coupling mechanism (4), first output terminal of described second coupling mechanism is connected with the input end of described long chirp grating sensor (5), the output terminal of long chirp grating sensor (5) connects second input end of second coupling mechanism (3), at the output terminal of described the 3rd coupling mechanism (4) the described photodetector (7) of connecting successively, data collecting card (8), signal analysis and processing section (9) and display device (10).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110069429A CN102175170B (en) | 2011-03-23 | 2011-03-23 | Detecting method and sensor for cracks of civil structure based on optical fiber long chirped grating frequency domain reflection technology |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110069429A CN102175170B (en) | 2011-03-23 | 2011-03-23 | Detecting method and sensor for cracks of civil structure based on optical fiber long chirped grating frequency domain reflection technology |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102175170A true CN102175170A (en) | 2011-09-07 |
| CN102175170B CN102175170B (en) | 2012-10-24 |
Family
ID=44518381
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110069429A Active CN102175170B (en) | 2011-03-23 | 2011-03-23 | Detecting method and sensor for cracks of civil structure based on optical fiber long chirped grating frequency domain reflection technology |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102175170B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103245299A (en) * | 2013-05-14 | 2013-08-14 | 东南大学 | High-spatial-resolution optical fiber sensing system based on wavelength tunable laser |
| CN103940360A (en) * | 2014-04-23 | 2014-07-23 | 鲁东大学 | Strain monitoring device based on cascade chirped fiber gratings |
| CN108917804A (en) * | 2018-09-03 | 2018-11-30 | 哈尔滨工业大学 | Quick long-distance distributed Brillouin light fiber sensing equipment based on chirp chain |
| CN109490220A (en) * | 2018-11-07 | 2019-03-19 | 河南工业大学 | A kind of large link rod fracture damage on-line detecting system and detection method based on long chirped fiber grating |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001108416A (en) * | 1999-10-04 | 2001-04-20 | Mitsubishi Heavy Ind Ltd | Optical fiber strain measuring instrument |
| JP2005009937A (en) * | 2003-06-17 | 2005-01-13 | National Institute Of Advanced Industrial & Technology | Strain- and ae-measuring apparatus using optical fiber sensor |
| CN101067609A (en) * | 2007-04-23 | 2007-11-07 | 哈尔滨工业大学 | Interference optical fiber sensor for composite material health monitoring |
| CN201974183U (en) * | 2011-03-23 | 2011-09-14 | 东南大学 | Sensor for crack detection of civil structure based on optical fiber long chirping grating frequency domain reflection technology |
-
2011
- 2011-03-23 CN CN201110069429A patent/CN102175170B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001108416A (en) * | 1999-10-04 | 2001-04-20 | Mitsubishi Heavy Ind Ltd | Optical fiber strain measuring instrument |
| JP2005009937A (en) * | 2003-06-17 | 2005-01-13 | National Institute Of Advanced Industrial & Technology | Strain- and ae-measuring apparatus using optical fiber sensor |
| CN101067609A (en) * | 2007-04-23 | 2007-11-07 | 哈尔滨工业大学 | Interference optical fiber sensor for composite material health monitoring |
| CN201974183U (en) * | 2011-03-23 | 2011-09-14 | 东南大学 | Sensor for crack detection of civil structure based on optical fiber long chirping grating frequency domain reflection technology |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103245299A (en) * | 2013-05-14 | 2013-08-14 | 东南大学 | High-spatial-resolution optical fiber sensing system based on wavelength tunable laser |
| CN103245299B (en) * | 2013-05-14 | 2016-02-03 | 东南大学 | A kind of high spatial resolution optical fiber sensing system based on Wavelength tunable laser |
| CN103940360A (en) * | 2014-04-23 | 2014-07-23 | 鲁东大学 | Strain monitoring device based on cascade chirped fiber gratings |
| CN103940360B (en) * | 2014-04-23 | 2016-10-05 | 鲁东大学 | A kind of strain monitoring device based on cascade chirped fiber grating |
| CN108917804A (en) * | 2018-09-03 | 2018-11-30 | 哈尔滨工业大学 | Quick long-distance distributed Brillouin light fiber sensing equipment based on chirp chain |
| CN109490220A (en) * | 2018-11-07 | 2019-03-19 | 河南工业大学 | A kind of large link rod fracture damage on-line detecting system and detection method based on long chirped fiber grating |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102175170B (en) | 2012-10-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103674117B (en) | Measure entirely method and device with weak optical fiber Bragg grating temperature and strain based on Raman scattering simultaneously | |
| CN103674086B (en) | Measure entirely with method and the device of weak optical fiber Bragg grating temperature and strain based on Brillouin scattering simultaneously | |
| CN103591971B (en) | A kind of localization method of fiber grating | |
| CN107036733B (en) | The many reference amounts Distributed Measurement System and measurement method of twin-core dim light grid array based on dark pulse light source | |
| CN109595470B (en) | Distributed pipeline detection method | |
| CN103940360B (en) | A kind of strain monitoring device based on cascade chirped fiber grating | |
| CN104132756B (en) | A kind of pressure sensing method utilizing the photonic crystal fiber grating of the bimodal reflectance spectrum of orthogonal polarization modes | |
| CN105371785A (en) | Curvature measurement method | |
| CN107515033A (en) | Point type liquid level sensor device and its measuring method based on optical frequency domain reflection technology | |
| CN102175170B (en) | Detecting method and sensor for cracks of civil structure based on optical fiber long chirped grating frequency domain reflection technology | |
| CN114111909A (en) | Fiber Bragg grating temperature and stress dual-parameter integrated sensing and demodulating system based on diffraction grating | |
| CN202033010U (en) | Distributed optical fiber sensor used for simultaneously monitoring engineering structure integral and local strains | |
| CN108007603B (en) | Multi-parameter distribution measuring system based on asymmetric double-core optical fiber | |
| CN201974183U (en) | Sensor for crack detection of civil structure based on optical fiber long chirping grating frequency domain reflection technology | |
| CN102176684B (en) | Distributed optical fiber sensor for simultaneously monitoring engineering structure entirety and local strain | |
| CN110595599B (en) | Method for reducing polarization fading of optical fiber vibration system and detection system applying same | |
| KR101498381B1 (en) | System for monitoring three-dimension shape of pipe-structure using fiber bragg grating sensor | |
| Liehr | Polymer optical fiber sensors in structural health monitoring | |
| CN201130028Y (en) | Optical fibre grating sensor demodulation instrument | |
| KR102036260B1 (en) | Submergence detection sensor using optical fiber grating | |
| Kwon et al. | Fiber optic sensor installation for monitoring of 4 span model bridge in UCF | |
| CN107631814B (en) | Optical self-coherent sensing optical path structure, frequency shift change detection method and sensing device | |
| CN203587125U (en) | Positioning system of fiber grating | |
| WO2023069492A1 (en) | Measuring fiber insertion losses in an optical fiber sensing system | |
| CN103245299B (en) | A kind of high spatial resolution optical fiber sensing system based on Wavelength tunable laser |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |