CN201974183U - Sensor for crack detection of civil structure based on optical fiber long chirping grating frequency domain reflection technology - Google Patents
Sensor for crack detection of civil structure based on optical fiber long chirping grating frequency domain reflection technology Download PDFInfo
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- CN201974183U CN201974183U CN2011200770145U CN201120077014U CN201974183U CN 201974183 U CN201974183 U CN 201974183U CN 2011200770145 U CN2011200770145 U CN 2011200770145U CN 201120077014 U CN201120077014 U CN 201120077014U CN 201974183 U CN201974183 U CN 201974183U
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Abstract
The utility model discloses a sensor for crack detection of civil structure based on an optical fiber long chirping grating frequency domain reflection technology. A detection method is as follows: a frequency domain analyzing technology for the optical fiber long chirping grating is used for forming a distributed optical fiber monitoring system so as to realize the monitoring on structural strain and crack location. Compared with the prior art, the sensor has the following advantages: the sensor has high spatial resolution, can realize micron dimension spatial resolution and has high spatial positioning precision; the sensor can realize the distributed detection on tiny cracks and damage of materials and has high sensitivity and good system stability; and the sensor has a simple structure, low cost and high cost performance.
Description
Technical field
The utility model relates to a kind of frequency-domain analysis technology distributed fiber-optic monitoring system and implementation method thereof based on the long chirp grating of optical fiber, can realize strain monitoring and location, crack to structure.
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 utility model provides a kind of sensor that is used for the civil structure crack detection based on the long chirp grating frequency domain of optical fiber reflection technology, is used for structure partial strain and crack detection, and measuring distance is long, and stability and repeatability are good, the precision height.
Technical solution of the present utility model is as follows:
A kind of sensor that is used for the civil structure crack detection 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 utility model 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 utlity model 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 utility model.
Fig. 2 is a kind of embodiment structural representation of the present utility model.
Embodiment
Below in conjunction with accompanying drawing the utility model is elaborated, but should not limit protection domain of the present utility model with this.
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 (1)
1. sensor that is used for the civil structure crack detection based on the long chirp grating frequency domain of optical fiber reflection technology, 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 |
|---|---|---|---|
| CN2011200770145U CN201974183U (en) | 2011-03-23 | 2011-03-23 | Sensor for crack detection of civil structure based on optical fiber long chirping grating frequency domain reflection technology |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200770145U CN201974183U (en) | 2011-03-23 | 2011-03-23 | Sensor for crack detection of civil structure based on optical fiber long chirping grating frequency domain reflection technology |
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| CN201974183U true CN201974183U (en) | 2011-09-14 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2011200770145U Expired - Lifetime CN201974183U (en) | 2011-03-23 | 2011-03-23 | Sensor for crack detection of civil structure based on optical fiber long chirping grating frequency domain reflection technology |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102175170A (en) * | 2011-03-23 | 2011-09-07 | 东南大学 | Detecting method and sensor for cracks of civil structure based on optical fiber long chirped grating frequency domain reflection technology |
| CN103278271A (en) * | 2013-04-27 | 2013-09-04 | 天津大学 | Distributed optical fiber monitoring system and monitoring method thereof |
| CN109613005A (en) * | 2018-12-20 | 2019-04-12 | 武汉隽龙科技股份有限公司 | Damage detecting method based on OFDR |
-
2011
- 2011-03-23 CN CN2011200770145U patent/CN201974183U/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102175170A (en) * | 2011-03-23 | 2011-09-07 | 东南大学 | Detecting method and sensor for cracks of civil structure based on optical fiber long chirped grating frequency domain reflection technology |
| CN102175170B (en) * | 2011-03-23 | 2012-10-24 | 东南大学 | Detecting method and sensor for cracks of civil structure based on optical fiber long chirped grating frequency domain reflection technology |
| CN103278271A (en) * | 2013-04-27 | 2013-09-04 | 天津大学 | Distributed optical fiber monitoring system and monitoring method thereof |
| CN109613005A (en) * | 2018-12-20 | 2019-04-12 | 武汉隽龙科技股份有限公司 | Damage detecting method based on OFDR |
| CN109613005B (en) * | 2018-12-20 | 2022-03-22 | 武汉昊衡科技有限公司 | OFDR-based damage detection method |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20110914 Effective date of abandoning: 20130227 |
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| RGAV | Abandon patent right to avoid regrant |