CN109799286A - A kind of reflection type optical fiber acoustic emission system and monitoring method - Google Patents
A kind of reflection type optical fiber acoustic emission system and monitoring method Download PDFInfo
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- CN109799286A CN109799286A CN201910194425.3A CN201910194425A CN109799286A CN 109799286 A CN109799286 A CN 109799286A CN 201910194425 A CN201910194425 A CN 201910194425A CN 109799286 A CN109799286 A CN 109799286A
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Abstract
The invention discloses a kind of reflection type optical fiber acoustic emission system and monitoring methods, including Optical Fibre Acoustic Emission Sensor, wavelength measurement module, circulator, coupler, tunable narrowband optical source, photodetector, preamplifier, sound emission capture card and computer；Fibre optical transmission sensor is fiber bragg grating, circulator is connected with tunable narrowband optical source, coupler and photodetector sequentially through optical fiber, ipsilateral two ports of coupler are connected with wavelength measurement module and circulator by optical fiber, the other side is connected with Optical Fibre Acoustic Emission Sensor by optical fiber, wavelength measurement module and tunable narrowband optical source are connect with computer by electrical signal line respectively, preamplifier is connected between photodetector and sound emission capture card by electrical signal line, and sound emission capture card is connect with computer by electrical signal line.The system has Microsecond grade response speed, can be with the solid structure damage and failure failure procedure in accurate measurements small space.
Description
Technical field
The present invention relates to material properties test technical fields, and in particular to one kind is suitable for small space temperature shock test
Reflection type optical fiber acoustic emission system and monitoring method.
Background technique
Damage, destruction or fail message under solid structure temperature match curing conditions can be obtained using acoustic emission system, it is existing
For acoustic emission system using piezoelectric material as sensor, probe size is big, cannot be mounted on slit space.Fibre optical sensor is because of body
Product is very thin, flexible, can be mounted on slit space, existing pertinent literature establishes optical fiber acoustic emission system, but most
System may not apply in caloric test because sensing principle is by temperature limiting.
Summary of the invention
In order to overcome the above technical defects, the present invention provides a kind of reflection type optical fiber acoustic emission system and monitoring method,
The system has Microsecond grade response speed, can be with the solid structure damage and failure failure procedure in accurate measurements small space.
In order to reach above-mentioned technical effect, the present invention provides the following technical scheme that
A kind of reflection type optical fiber acoustic emission system, including Optical Fibre Acoustic Emission Sensor, wavelength measurement module, circulator, coupling
Clutch, tunable narrowband optical source, photodetector, preamplifier, sound emission capture card and computer；The fibre optical transmission passes
Sensor is fiber bragg grating, the circulator and tunable narrowband optical source, coupler and photodetector sequentially through
Optical fiber is connected, ipsilateral two ports of the coupler are connected with wavelength measurement module and circulator by optical fiber, the other side and
Optical Fibre Acoustic Emission Sensor is connected by optical fiber, and the wavelength measurement module and tunable narrowband optical source pass through with computer respectively
Electrical signal line connection, the preamplifier are connected between photodetector and sound emission capture card by electrical signal line, institute
It states sound emission capture card and is connect with computer by electrical signal line.
Further technical solution is that the Optical Fibre Acoustic Emission Sensor is no coat, length within the scope of 9~11mm
Fiber bragg grating.
Further technical solution is linear zone > 80pm reflectivity >=80% of the fiber bragg grating.
Further technical solution is wide spectrum light source built in the wavelength measurement module, wave-length coverage is 1520~
1570nm, power are less than 1mW.
Further technical solution is that the wavelength of the tunable narrowband optical source can be with continuous tuning, tuning range
1520nm~1570nm, precision≤50pm, width≤10pm, power >=5mW light source.
The present invention also provides a kind of monitoring method for carrying out explosive rupture failure using above-mentioned optical fiber acoustic emission system,
Method includes the following steps:
(1) light source parameters are arranged: using the central wavelength of wavelength measurement module measurement fiber bragg grating, according to measurement
Central wavelength pass through the wavelength of computer installation tunable narrowband optical source；
(2) it scaling method: centered on fiber bragg grating, is generated on the different directions of explosive surface using disconnected lead method
Sound pressure signal demarcates fiber bragg grating acoustic emission sensor in conjunction with piezo-electric resonance type acoustic emission sensor, obtains
The fiber bragg grating amplitude that disconnected lead method releases energy on the different directions of explosive surface；
(3) explosive damage monitoring method: fiber bragg grating is pasted onto explosive surface, adjusts optical source wavelength, to fried
Medicine carries out mechanical load destruction, and synchronous averaging runs optical fiber acoustic emission system, stops optical fiber sound emission after explosive destroys
System.
Further technical solution is, described that tunable narrow-band light is arranged according to the spectral signature of measurement in step (1)
The wavelength in source makes the wavelength of light source be in the half-wavelength position of fiber bragg grating.
Further technical solution is that after the environment temperature of fiber bragg grating changes, wavelength measurement module tracks light
The central wavelength of fine Bragg grating, thus the wavelength of adjustment tunable narrowband optical source transmitting in real time.
The present invention is further detailed below, the wavelength measurement module in the device is used for real-time measurement optical fiber sound
The central wavelength lambda of emission sensorB, built-in wide spectrum light source, wave-length coverage is 1520~1570nm, and power is less than 1mW, utilizes light
For fine Bragg grating as Optical Fibre Acoustic Emission Sensor, reflectance spectrum is an arc-shaped wave crest, λBFor center wavelength, wave crest
The corresponding spectral width of the half of value is 2 λb, computer by wavelength measurement module obtain time t1 when λB(t1), this system
In the light source Optical Fibre Acoustic Emission Sensor is incident on by circulator and coupler, Optical Fibre Acoustic Emission Sensor reflected light passes through coupling
Clutch is divided into two bundles, and wavelength measurement module tracks the wavelength of Optical Fibre Acoustic Emission Sensor by coupler.Wavelength value λL(t2) pass through
The λ that computer obtainsB(t1) assignment is carried out, make λL(t2)=λB(t1)+λbOr λL(t2)=λB(t1)-λb, t2-t1> 50 μ s and more
It is better close to 50 μ s, show that optical source wavelength is consistent with Optical Fibre Acoustic Emission Sensor wavelength response, and 20kHz (1/50 μ s) can be distinguished
Above acoustic emission signal, there are three ports for the circulator tool in the application, respectively 1. port, 2. port, 3. port, this three
The one-way transmission function of light is realized in a port, i.e. the 1. port of the port of port → 2. → 3., wherein 1. port to 2. port light loss
The smaller the better, 1. port to 3. port light intensity is 0；2. port is the smaller the better to 1. port light intensity, 2. port to 3. port light loss
It consumes the smaller the better；3. port is the smaller the better to 2. port light intensity, 3. port to 1. port light intensity is 0.Photoelectricity in the application is visited
Surveying device sensitivity, the higher the better, and sound emission light intensity signal is converted into analog voltage signal.Photodetector passes through in this system
The total light intensity I of circulator reception optical fiber acoustic emission sensor reflection, total light intensity I include wavelength measurement module built-in broadband light source light
Strong IWWith tunable narrowband optical source light intensity INTwo parts, because the latter is much larger than the former, it is possible to think total light intensity I close to IN,
Wherein wideband light source light intensity IWVery little is not shown.Preamplifier is for receiving analog voltage signal in the application, and is put
Greatly, sound emission capture card is used to acquire the acoustic emission signal of preamplifier amplification, is input to computer.
Compared with prior art, the present invention having the following beneficial effects:
The present invention provide it is a kind of using fiber bragg grating as acoustic emission sensor, using wavelength measurement module with couple
The central wavelength of device real-time tracking fiber bragg grating establishes a kind of monitoring in conjunction with sound emission capture card and preamplifier
The optical fiber acoustic emission system of solid structure alternating temperature damage and failure process.The system has Microsecond grade response speed, can accurately supervise
Survey the solid structure damage and failure failure procedure under alternating temperature special environment in small space.
Detailed description of the invention
Fig. 1 is reflection type optical fiber acoustic emission system overall structure diagram of the invention；
Fig. 2 is reflection type optical fiber acoustic emission sensor reflectance spectrum schematic diagram of the invention；
Fig. 3 is the spectral schematic that photodetector is reached in this system.
Specific embodiment
Embodiment 1
A kind of a kind of reflection type optical fiber acoustic emission system as shown in Figure 1, including Optical Fibre Acoustic Emission Sensor, wavelength measurement
Module, circulator, coupler, tunable narrowband optical source, photodetector, preamplifier, sound emission capture card and computer；
The fibre optical transmission sensor is fiber bragg grating, and the circulator and tunable narrowband optical source, coupler and photoelectricity are visited
It surveys device to be connected sequentially through optical fiber, ipsilateral two ports of the coupler and wavelength measurement module and circulator pass through optical fiber
It is connected, the other side is connected with Optical Fibre Acoustic Emission Sensor by optical fiber, the wavelength measurement module and tunable narrowband optical source point
It is not connect with computer by electrical signal line, the preamplifier passes through electricity between photodetector and sound emission capture card
Signal wire connection, the sound emission capture card are connect with computer by electrical signal line.Wherein there are three ports for circulator tool, 1.
Port is the smaller the better to 2. port light loss, and 1. port to 3. port light intensity is 0；2. port is the smaller the better to 1. port light intensity,
2. port is the smaller the better to 3. port light loss；3. port is the smaller the better to 2. port light intensity, 3. port is to 1. port light intensity
0.The coupler is arranged between the optical fiber circulator and the fiber bragg grating, and the light loss of coupler is smaller more
Good, i.e., 1. port and the difference of the 2. sum of port light intensity and 3. port light intensity are the smaller the better.Photodetector passes through ring in this system
The total light intensity I of shape device reception optical fiber acoustic emission sensor reflection, total light intensity I include wavelength measurement module built-in broadband light source intensity
IWWith tunable narrowband optical source light intensity INTwo parts, because the latter is much larger than the former, it is possible to think total light intensity I close to IN,
Middle width strip light source intensity IWVery little is not shown.The Optical Fibre Acoustic Emission Sensor is no coat, length in 9~11mm range
Interior fiber bragg grating.Linear zone > 80pm reflectivity >=80% of the fiber bragg grating.The wavelength measurement
Wide spectrum light source built in module, wave-length coverage are 1520~1570nm, and power is less than 1mW.The wavelength of the tunable narrowband optical source
It can be 1520nm~1570nm, precision≤50pm, width≤10pm, power >=5mW light source with continuous tuning, tuning range.
The light source is incident on Optical Fibre Acoustic Emission Sensor, wavelength value λ by circulator in this systemL(t2) pass through the λ of computer acquisitionB
(t1) assignment is carried out, make λL(t2)=λB(t1)+λbOr λL(t2)=λB(t1)-λb, t2-t1> 50 μ s and closer to 50 μ s it is better,
Show that optical source wavelength is consistent with Optical Fibre Acoustic Emission Sensor wavelength response, and the sound emission of 20kHz (1/50 μ s) or more can be distinguished
Signal with preamplifier in the application for receiving analog voltage signal, and is amplified, and sound emission capture card is for acquiring
The acoustic emission signal of preamplifier amplification, is input to computer.
Using reflection type optical fiber acoustic emission system of the present invention carry out explosive rupture failure monitoring method, this method include with
Lower step:
(1) light source parameters are arranged: using the central wavelength of wavelength measurement module measurement fiber bragg grating, according to measurement
Central wavelength pass through the wavelength of computer installation tunable narrowband optical source and output energy；
(2) it scaling method: centered on fiber bragg grating, is generated on the different directions of explosive surface using disconnected lead method
Sound pressure signal demarcates fiber bragg grating acoustic emission sensor in conjunction with piezo-electric resonance type acoustic emission sensor, obtains
The fiber bragg grating amplitude that disconnected lead method releases energy on the different directions of explosive surface；
(3) explosive damage monitoring method: fiber bragg grating is pasted onto explosive surface, adjusts optical source wavelength, to fried
Medicine carries out mechanical load destruction, and synchronous averaging runs optical fiber acoustic emission system, stops optical fiber sound emission after explosive destroys
System.
Wavelength measurement module obtains fiber bragg grating central wavelength lambda by couplerB, computer, which will contain, biases wave
Long and λBIt is assigned to tunable narrowband optical source, light source launches narrow band light, is incident on optical fiber Bradley by circulator and coupler
The intensity signal of lattice grating, optical grating reflection is incident on photodetector by coupler and circulator.When being pasted with optical fiber Bradley
When the tested material failure of lattice grating destroys, the dynamic intensity signal that photodetector obtains can be converted into electric signal, preceding
It after setting amplifier enhancing, is obtained by sound emission capture card, and saves and be shown in calculating.Advantage is when tested solid is in alternating temperature
Under environment, optical fiber acoustic emission system of the invention will not because of optic fiber grating wavelength variation and fail, still can effectively supervise
Measure material failure signal.
Although reference be made herein to invention has been described for explanatory embodiment of the invention, and above-described embodiment is only this hair
Bright preferable embodiment, embodiment of the present invention are not limited by the above embodiments, it should be appreciated that those skilled in the art
Member can be designed that a lot of other modification and implementations, these modifications and implementations will fall in principle disclosed in the present application
Within scope and spirit.
Claims (8)
1. a kind of reflection type optical fiber acoustic emission system, which is characterized in that including Optical Fibre Acoustic Emission Sensor, wavelength measurement module,
Circulator, coupler, tunable narrowband optical source, photodetector, preamplifier, sound emission capture card and computer；It is described
Fibre optical transmission sensor is fiber bragg grating, the circulator and tunable narrowband optical source, coupler and photodetector
It is connected sequentially through optical fiber, ipsilateral two ports and the wavelength measurement module and circulator of the coupler pass through optical fiber phase
Even, the other side is connected with Optical Fibre Acoustic Emission Sensor by optical fiber, the wavelength measurement module and tunable narrowband optical source difference
It is connect with computer by electrical signal line, the preamplifier passes through telecommunications between photodetector and sound emission capture card
The connection of number line, the sound emission capture card are connect with computer by electrical signal line.
2. reflection type optical fiber acoustic emission system according to claim 1, which is characterized in that the Optical Fibre Acoustic Emission Sensor
It is the fiber bragg grating of no coat, length within the scope of 9~11mm.
3. reflection type optical fiber acoustic emission system according to claim 1, which is characterized in that the fiber bragg grating
Linear zone > 80pm reflectivity >=80%.
4. reflection type optical fiber acoustic emission system according to claim 1, which is characterized in that built in the wavelength measurement module
Wide spectrum light source, wave-length coverage are 1520~1570nm, and power is less than 1mW.
5. reflection type optical fiber acoustic emission system according to claim 1, which is characterized in that the tunable narrowband optical source
Wavelength can be 1520nm~1570nm, precision≤50pm, width≤10pm, power >=5mW light with continuous tuning, tuning range
Source.
6. a kind of carry out explosive rupture failure using reflection type optical fiber acoustic emission system described in 5 any one of Claims 1 to 5
Monitoring method, which comprises the following steps:
(1) light source parameters are arranged: using the central wavelength of wavelength measurement module measurement fiber bragg grating, according in measurement
The long wavelength for passing through computer installation tunable narrowband optical source of cardiac wave；
(2) scaling method: centered on fiber bragg grating, acoustic pressure is generated on the different directions of explosive surface using disconnected lead method
Signal demarcates fiber bragg grating acoustic emission sensor in conjunction with piezo-electric resonance type acoustic emission sensor, obtains optical fiber
The Bragg grating amplitude that disconnected lead method releases energy on the different directions of explosive surface；
(3) explosive damage monitoring method: being pasted onto explosive surface for fiber bragg grating, adjust optical source wavelength, to explosive into
Row mechanical load is destroyed, and synchronous averaging runs optical fiber acoustic emission system, stops optical fiber acoustic emission system after explosive destroys.
7. the monitoring method of explosive rupture failure according to claim 6, which is characterized in that in step (1), described
According to the wavelength of the central wavelength setting tunable narrowband optical source of measurement, the wavelength of light source is made to be in the half-wave of fiber bragg grating
Long position.
8. the monitoring method of explosive rupture failure according to claim 6, which is characterized in that the ring of fiber bragg grating
After border temperature changes, wavelength measurement module meeting real-time tracing obtains fiber bragg grating central wavelength, and will by computer
The wavelength of variation is assigned to tunable narrowband optical source.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2741270C1 (en) * | 2020-06-08 | 2021-01-22 | Общество с ограниченной ответственностью Научно-инновационный центр "Институт развития исследований, разработок и трансферта технологий" | Fibre-optic ring acoustic emission sensor |
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| DE10210787A1 (en) * | 2002-03-12 | 2003-10-09 | Daimler Chrysler Ag | Device for measuring physical parameters in solid bodies uses light wave guides on a structure, an input fiber Bragg grid and a control unit. |
| CN101813496A (en) * | 2010-04-15 | 2010-08-25 | 电子科技大学 | Fiber Bragg grating sensor and Raman sensor-fused sensing system |
| CN102419348A (en) * | 2011-08-19 | 2012-04-18 | 北京航空航天大学 | Acoustic emission signal power type nondestructive detecting method based on fiber Bragg grating |
| CN108195943A (en) * | 2018-03-12 | 2018-06-22 | 中国工程物理研究院化工材料研究所 | A kind of optical fiber acoustic emission system and its monitoring method for monitoring explosive damage and failure process |
-
2019
- 2019-03-14 CN CN201910194425.3A patent/CN109799286A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10210787A1 (en) * | 2002-03-12 | 2003-10-09 | Daimler Chrysler Ag | Device for measuring physical parameters in solid bodies uses light wave guides on a structure, an input fiber Bragg grid and a control unit. |
| CN101813496A (en) * | 2010-04-15 | 2010-08-25 | 电子科技大学 | Fiber Bragg grating sensor and Raman sensor-fused sensing system |
| CN102419348A (en) * | 2011-08-19 | 2012-04-18 | 北京航空航天大学 | Acoustic emission signal power type nondestructive detecting method based on fiber Bragg grating |
| CN108195943A (en) * | 2018-03-12 | 2018-06-22 | 中国工程物理研究院化工材料研究所 | A kind of optical fiber acoustic emission system and its monitoring method for monitoring explosive damage and failure process |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2741270C1 (en) * | 2020-06-08 | 2021-01-22 | Общество с ограниченной ответственностью Научно-инновационный центр "Институт развития исследований, разработок и трансферта технологий" | Fibre-optic ring acoustic emission sensor |
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