CN202693272U - A device for monitoring looseness of bolts of a flange of a sensibilization type optical fiber grating - Google Patents
A device for monitoring looseness of bolts of a flange of a sensibilization type optical fiber grating Download PDFInfo
- Publication number
- CN202693272U CN202693272U CN 201220123673 CN201220123673U CN202693272U CN 202693272 U CN202693272 U CN 202693272U CN 201220123673 CN201220123673 CN 201220123673 CN 201220123673 U CN201220123673 U CN 201220123673U CN 202693272 U CN202693272 U CN 202693272U
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- Prior art keywords
- flange
- hold
- fiber grating
- optical fiber
- monitoring device
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- 239000013307 optical fiber Substances 0.000 title claims abstract description 21
- 238000012544 monitoring process Methods 0.000 title abstract description 9
- 239000000835 fiber Substances 0.000 claims abstract description 23
- 238000012806 monitoring device Methods 0.000 claims description 27
- 230000000712 assembly Effects 0.000 claims description 18
- 238000000429 assembly Methods 0.000 claims description 18
- 229910000831 Steel Inorganic materials 0.000 claims description 14
- 239000010959 steel Substances 0.000 claims description 14
- 230000001235 sensitizing effect Effects 0.000 claims description 10
- 239000003822 epoxy resin Substances 0.000 claims description 5
- 229920000647 polyepoxide Polymers 0.000 claims description 5
- 230000004323 axial length Effects 0.000 claims description 3
- 230000035945 sensitivity Effects 0.000 abstract description 12
- 238000005259 measurement Methods 0.000 abstract description 3
- 238000000034 method Methods 0.000 description 7
- 230000008901 benefit Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000007767 bonding agent Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 210000001503 joint Anatomy 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
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Abstract
The utility model provides a device for monitoring the looseness of bolts of a flange of a sensibilization type optical fiber grating, belonging to the field of measurement. The device comprises an optical fiber engraved with a grating region. Two fixed supporting seats are arranged at the two sides of the flange. A protection pipe is arranged in the grating region of the optical fiber grating. Clamping members are respectively arranged at the two ends of the protection pipe. The two clamping members are correspondingly and fixedly connected with the fiber at the two ends of the protection pipe respectively. The two clamping members are respectively and fixedly connected with the fixed supporting seats at the two sides of the flange. The device is capable of effectively monitoring the tiny deformation generated by the looseness of the bolts of the flange, and is adjustable in sensitivity and convenient to adapt to the requirements of actual projects. A main body part of the device for monitoring is convenient to detach and replace and influences on a previous structure are very small. The device, which is a high-sensitivity device for nondestructive detecting of the looseness of the bolts of the flange, is convenient to popularize and apply. The device can be widely applied to the field of monitoring the looseness of the bolts of a flange connecting structure.
Description
Technical field
The utility model belongs to detection field, relates in particular to a kind of device for the flange bolt connection status is monitored.
Background technology
" flange bolt connection " is the main connected mode of pressure vessel, tall and slender structure (such as electric transmission pole tower, television tower) member.
Because its coupling bolt-nut is structurally without self-locking or locking structure, so at the place that is connected and fixed with bolts, under long-term load action, loosening phenomenon can appear in bolt, as in time not finding, can cause the expansion of flange joint damage, and then make the structure failure.
Past attempts adopted the mode with " double nut self-locking " to attempt to stop the loosening problem of coupling bolt, but because aspects such as operational method, implementation cost or applicable situations, failed to solve fully the loosening problem of flange bolt always.
Therefore, connection is effectively monitored to flange bolt, finds in time whether flange bolt becomes flexible, to ensureing that structural safety has important realistic meaning.
Open day is on September 27th, 2011, publication number is to disclose " a kind of nuclear main pump with bolt looseness monitoring device and monitoring method thereof " in the Chinese invention patent application of CN 102170392A, it is by arranging respectively corresponding a CCD digital camera and the 2nd CCD digital camera in the loosening monitoring device of swivel bolt group and the loosening monitoring device of static bolt group, and in conjunction with the computing machine that contains picture recognition module and early warning system, calculate one by one the distance between the scale mark of each scale mark that carries out the bolt that uniqueness indicates and corresponding parts that are fixed, carry out different early warning according to the span of this distance and process.
Clearly, although technique scheme is effectively succinct, be only suitable in some other visual plant and key position, and implementation cost is higher, implements for extensive employing and spread, have certain difficulty.
Fiber grating is to develop in recent years rapidly New Generation Optical passive device, plays an important role in association areas such as optical fiber communication and Fibre Optical Sensors.
The sensor of development has highly sensitive, the characteristics such as volume is little, anti-electromagnetic-radiation take fiber grating as sensing element, is widely used in the measurement of the physical quantitys such as strain, temperature.
At present existing research directly is installed on the position that flange connects with fiber-optic grating sensor, utilizes fiber-optic grating sensor to detect the strain variation of the flange connections that bolt looseness causes, and judges accordingly whether bolt becomes flexible.
But in Practical Project, the strain variation of the caused flange link position of bolt looseness is minimum, adopts effectively monitoring bolt connection changing condition of common fiber-optic grating sensor.
The utility model content
Technical problem to be solved in the utility model provides a kind of sensitizing type fiber grating flange bolt looseness monitoring device, it takes full advantage of the own characteristic of optical fiber grating sensing element, more common fiber-optic grating sensor has higher sensitivity, can effectively monitor the microdeformation that the flange bolt looseness produces, its sensitivity is adjustable, is convenient to adapt to the demand of Practical Project; The main part of its monitoring device is convenient to dismounting and is changed, and is very little, easy to utilize on the original structure impact, is the loosening the cannot-harm-detection device of a kind of highly sensitive flange bolt.
The technical solution of the utility model is: a kind of sensitizing type fiber grating flange bolt looseness monitoring device is provided, comprises the optical fiber that is carved with the grating grid region, its feature: in flange both sides correspondence two hold-down supports are set; Part arranges a protection tube in the grid region of fiber grating; At the protection tube two ends one hold assembly is set respectively; Described two hold assemblies respectively with corresponding the fixing as one of optical fiber at protection tube two ends; Described two hold assemblies are affixed with the hold-down support of flange both sides respectively.
Its described protection tube and hold assembly are steel pipe.
Its described two hold assemblies are through the optical fiber at epoxy resin and protection tube two ends corresponding fixing as one respectively.
Concrete, the length of described protection tube equals two distances between the hold assembly opposite end.
The axial length sum of described protection tube and two hold assemblies equals the distance between two hold-down support outboard ends corresponding to flange both sides.
Described two hold assemblies are affixed respectively through the hold-down support of securing member and flange both sides.
Compared with the prior art, the utility model has the advantages that:
1. adopt the mode to the fiber grating enhanced sensitivity, realized that highly sensitive flange bolt becomes flexible Non-Destructive Testing;
2. can cause according to bolt looseness the calculated value of flange strain, change the sensitivity coefficient of monitoring device, to adapt to the demand of Practical Project;
3. the monitoring device mounting process is simple, and is cheap, and possesses high, the advantages such as volume is little, anti-electromagnetic-radiation of optical fiber grating sensing element sensitivity; The main part of monitoring device is convenient to dismounting and is changed, and is very little, easy to utilize on the original structure impact.
Description of drawings
Fig. 1 is the structural representation of the utility model monitoring device.
1 is flange among the figure, and 2 is bolt, and 3 for being carved with the optical fiber of grating, and 4 are the protection steel pipe, and 5 is hold assembly, and 6 is hold-down support, and L is two distances between the hold-down support, L
fBe the length (i.e. distance between two hold assemblies) of protection steel pipe, Ls is the length of two hold assemblies.
Embodiment
Below in conjunction with accompanying drawing the utility model is described further.
Among Fig. 1; this monitoring device; comprise the optical fiber 3 that is carved with grating; be provided with two hold-down supports 6 in flange 1 both sides correspondence; outer setting in fiber grating grid region part has a protection steel pipe 4; be respectively arranged with 5, two hold assemblies of a hold assembly at the protection tube two ends affixed with the hold-down support of flange both sides respectively.
Protection tube and hold assembly are steel pipe.
Two hold assemblies are through the optical fiber at epoxy resin and protection tube two ends corresponding fixing as one respectively.
Two hold assemblies are affixed respectively through the hold-down support of securing member and flange both sides.
As seen from the figure, the length L of protection tube
fEqual two distances between the hold assembly opposite end.
The axial length sum L of protection tube and two hold assemblies
f+ Ls equals the distance L between two hold-down support outboard ends corresponding to flange both sides.
The principle summary of the technical program:
If the distance between two hold-down supports is L, the length of protection steel pipe (i.e. distance between two hold assemblies) is L
f, the length of two hold assemblies is Ls.
Suppose the distortion that bolt looseness makes the ring flange of this monitoring device position produce Δ L, the distortion of corresponding hold assembly and fiber grating is respectively Δ Ls and Δ L
f(the protection steel pipe does not deform), the internal force of this device that distortion causes is F.
Ignore the impact of bonding agent between hold assembly and the optical fiber, by mechanics of materials ultimate principle as can be known
ΔL=2ΔL
s+ΔL
f=2ε
sL
s+ε
fL
f （4）
In the formula, ε, ε
s, ε
fBe respectively the strain of whole monitoring device, hold assembly, fiber grating grid region part, E
s, E
fBe respectively the elastic modulus of steel and optical fiber, A
s, A
fBe respectively area of section (because the A of hold assembly and optical fiber
f＜＜A
s, ignore hold assembly inner fiber area of section partly).Bring formula (4) into formula (3), vertical (1) (2) cancellation F in parallel can get:
With formula (5) distortion,
Wherein,
Be the enhanced sensitivity coefficient of this monitoring device.
In the Practical Project, because E
fA
f＜＜E
sA
sSo, can be by reducing L
fImprove the sensitivity of this device.
The concrete method for making of monitoring device is; the optical fiber 3 that at first will be carved with grating penetrates protection steel pipe 4; make the grid region part be positioned at protection steel pipe 4; and directly do not contact with protection steel pipe 4; use epoxide-resin glue that hold assembly 5 is bonded in the fiber section of protection steel pipe 4 both sides and makes epoxy resin cure; hold-down support 6 is welded on flange 1 both sides, at last hold assembly 5 is installed on the hold-down support 6 in bolted mode.
Behind the bolt looseness on the flange, the strain that monitoring device and fiber grating grid region part are produced is respectively ε and ε
fAs previously mentioned, ε and ε
fThe pass be ε
f=K ε.Because ε
fCan directly record by the demodulation instrument, can be calculated by this formula the strain value ε at this place on the flange.
That is, for the strain stress of this setting position on the caused flange of bolt looseness, actual monitoring value ε
fε is amplified K doubly, thereby realized the enhanced sensitivity measurement.
For structures different in the Practical Project, can be by changing the length value L of protection steel pipe
f, adjust suitable monitoring device sensitivity coefficient.
The loosening monitoring device of the disclosed sensitizing type flange bolt based on fiber grating of the technical program, its mounting process is simple, and is cheap, and possesses high, the advantages such as volume is little, anti-electromagnetic-radiation of optical fiber grating sensing element sensitivity; Can cause according to bolt looseness the calculated value of flange strain, change the sensitivity coefficient of monitoring device, to adapt to the demand of Practical Project; The main part of monitoring device is convenient to dismounting and is changed, and is very little on the original structure impact, is the loosening the cannot-harm-detection device of a kind of highly sensitive flange bolt.
The utility model can be widely used in the bolt looseness monitoring field of flange connection.
Claims (6)
1. sensitizing type fiber grating flange bolt looseness monitoring device comprises the optical fiber that is carved with the grating grid region, its feature:
In flange both sides correspondence two hold-down supports are set;
Part arranges a protection tube in the grid region of fiber grating;
At the protection tube two ends one hold assembly is set respectively;
Described two hold assemblies respectively with corresponding the fixing as one of optical fiber at protection tube two ends;
Described two hold assemblies are affixed with the hold-down support of flange both sides respectively.
2. according to sensitizing type fiber grating flange bolt looseness monitoring device claimed in claim 1, it is characterized in that described protection tube and hold assembly are steel pipe.
3. according to sensitizing type fiber grating flange bolt looseness monitoring device claimed in claim 1, it is characterized in that described two hold assemblies are through the optical fiber at epoxy resin and protection tube two ends corresponding fixing as one respectively.
4. according to sensitizing type fiber grating flange bolt looseness monitoring device claimed in claim 1, it is characterized in that the length of described protection tube equals two distances between the hold assembly opposite end.
5. according to sensitizing type fiber grating flange bolt looseness monitoring device claimed in claim 1, it is characterized in that the axial length sum of described protection tube and two hold assemblies, equal the distance between two hold-down support outboard ends corresponding to flange both sides.
6. according to sensitizing type fiber grating flange bolt looseness monitoring device claimed in claim 1, it is characterized in that described two hold assemblies are affixed respectively through the hold-down support of securing member and flange both sides.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220123673 CN202693272U (en) | 2012-03-28 | 2012-03-28 | A device for monitoring looseness of bolts of a flange of a sensibilization type optical fiber grating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220123673 CN202693272U (en) | 2012-03-28 | 2012-03-28 | A device for monitoring looseness of bolts of a flange of a sensibilization type optical fiber grating |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202693272U true CN202693272U (en) | 2013-01-23 |
Family
ID=47548876
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220123673 Expired - Lifetime CN202693272U (en) | 2012-03-28 | 2012-03-28 | A device for monitoring looseness of bolts of a flange of a sensibilization type optical fiber grating |
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| CN (1) | CN202693272U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102706544A (en) * | 2012-03-28 | 2012-10-03 | 上海市电力公司 | Method and device for monitoring looseness of flange bolt of sensibilization type optical fibber grating |
| CN104613876A (en) * | 2015-01-30 | 2015-05-13 | 华东理工大学 | Flange deflection angel monitoring system |
-
2012
- 2012-03-28 CN CN 201220123673 patent/CN202693272U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102706544A (en) * | 2012-03-28 | 2012-10-03 | 上海市电力公司 | Method and device for monitoring looseness of flange bolt of sensibilization type optical fibber grating |
| CN104613876A (en) * | 2015-01-30 | 2015-05-13 | 华东理工大学 | Flange deflection angel monitoring system |
| CN104613876B (en) * | 2015-01-30 | 2017-10-27 | 华东理工大学 | A kind of flange deflection angle monitoring system |
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|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20130123 |