CN115219082A - Temperature self-compensation omnibearing radial pressure sensing cable based on fiber bragg grating - Google Patents
Temperature self-compensation omnibearing radial pressure sensing cable based on fiber bragg grating Download PDFInfo
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- CN115219082A CN115219082A CN202210967921.XA CN202210967921A CN115219082A CN 115219082 A CN115219082 A CN 115219082A CN 202210967921 A CN202210967921 A CN 202210967921A CN 115219082 A CN115219082 A CN 115219082A
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- 239000000835 fiber Substances 0.000 title claims abstract description 131
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 61
- 239000010959 steel Substances 0.000 claims abstract description 61
- 238000004804 winding Methods 0.000 claims abstract description 21
- 239000010410 layer Substances 0.000 claims description 12
- 238000005253 cladding Methods 0.000 claims description 10
- 239000011241 protective layer Substances 0.000 claims description 5
- 239000003292 glue Substances 0.000 claims description 4
- 230000001050 lubricating effect Effects 0.000 claims description 4
- 230000008447 perception Effects 0.000 claims 1
- 238000009941 weaving Methods 0.000 abstract description 6
- 239000013307 optical fiber Substances 0.000 description 17
- 238000000034 method Methods 0.000 description 9
- 238000001514 detection method Methods 0.000 description 7
- 238000005259 measurement Methods 0.000 description 6
- 230000036541 health Effects 0.000 description 5
- 230000035882 stress Effects 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 238000012544 monitoring process Methods 0.000 description 4
- 238000001125 extrusion Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000009530 blood pressure measurement Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006355 external stress Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
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Abstract
The invention provides a temperature self-compensation omnibearing radial pressure sensing cable based on fiber bragg gratings, which comprises a plurality of steel strands, a first fiber bragg grating and a second fiber bragg grating, wherein the steel strands are spirally bundled in the same direction to form strands, the first fiber bragg grating is wound on the outer surface of the strands along the bundling direction of the steel strands and is positioned in gaps among the steel strands, the second fiber bragg grating is wound on the outer surface of the strands along the opposite direction of the bundling direction of the steel strands, the first fiber bragg grating is used for sensing and transmitting temperature signals, and the second fiber bragg grating is used for sensing and transmitting radial pressure signals of the steel strands. According to the invention, the second fiber bragg grating can be used for detecting the radial pressure by winding the second fiber bragg grating along the direction opposite to the steel strand weaving direction, and the temperature can be only measured by winding the first fiber bragg grating along the steel strand weaving direction, so that the temperature compensation can be carried out on the second fiber bragg grating for measuring the radial force, and the higher precision is realized.
Description
Technical Field
The invention relates to the technical field of optical fiber sensing, in particular to a temperature self-compensation omnibearing radial pressure sensing cable based on an optical fiber grating.
Background
In recent years, with the rapid development of traffic networks in China and the continuous innovation of bridge construction methods, bridges with cable-stayed bridges, suspension bridges and other cable structures with large span play a more important role in traffic. The key stress part in the cable-stayed bridge or the suspension bridge is the pulling sling, which plays an important role in the whole stress system of the bridge, and actually, the health condition of the cable is related to the safety of the whole bridge. The traditional cable force detection has a plurality of methods such as a pressure test method, a pressure sensor measurement method, a magnetic flux measurement method, a vibration frequency method and the like, the methods are all used for indirectly measuring the internal stress state of the cable in an external detection mode, and the method cannot directly reflect the real condition of the cable force due to the influence of instruments, a calculation mode, boundary conditions, cable length, external environment, inclination and sag, so that the health state of the cable cannot be well estimated.
The fiber bragg grating can be widely applied to structural health monitoring due to the advantages of electromagnetic interference resistance, small size, easiness in networking and the like, the problem of pain in cable force detection of a bridge cable can be well solved, the fiber bragg grating pressure sensor is small in size and large in measurement range, the fiber bragg grating and an internal steel wire of the fiber bragg grating can be tightly attached together in the cable manufacturing process, so that the fiber bragg grating directly participates in the deformation process of the steel wire and is converted into cable force, the method is not influenced by the external environment, real-time monitoring can be achieved, the measurement range is large, and the method can be used as an effective means for cable health detection.
However, the health condition of the whole cable cannot be fully evaluated only by the axial cable force, because the cable contains a plurality of strands of steel wires, and the strands of steel wires or steel strands have a squeezing relationship, so that radial force is generated in the cable, and the cable may be loosened or damaged during working to cause local stress loss, which not only causes the change of the cable force, but also causes the change of the radial force nearby, so that the monitoring is not accurate.
Disclosure of Invention
In view of this, it is necessary to provide a temperature self-compensation omnibearing radial pressure sensing cable based on fiber bragg grating, which solves the problem of inaccurate detection of radial pressure of the cable in the prior art.
The invention provides a temperature self-compensation omnibearing radial pressure sensing cable based on fiber bragg grating, comprising:
the steel strand is spirally bundled along the same direction to form a strand, the first fiber bragg grating is wound on the outer surface of the strand along the strand bundling direction and is positioned in a gap between the steel strands, the second fiber bragg grating is wound on the outer surface of the strand along the opposite direction of the strand bundling direction, the first fiber bragg grating is used for sensing and transmitting temperature signals, and the second fiber bragg grating is used for sensing and transmitting radial pressure signals of the steel strands.
Optionally, the gaps between the steel strands are coated with lubricating glue.
Optionally, there is at least one second fiber grating, and when there are a plurality of second fiber gratings, the second fiber gratings are parallel to each other.
Optionally, the fiber bragg grating further comprises an auxiliary winding belt, the second fiber bragg grating is fixed on the auxiliary winding belt, and the auxiliary winding belt is wound on the outer surface of the strand along the direction opposite to the strand binding direction of the steel strands.
Optionally, the optical fiber grating further comprises an outer cladding layer, and the outer cladding layer is sleeved on the strand, the first optical fiber grating and the second optical fiber grating.
Optionally, the outer cladding includes a first sleeve, a second sleeve, a wrapping tape, and a protection layer, the first sleeve is sleeved on the strand and the first fiber grating, the second fiber grating is wound on the outer surface of the first sleeve along the opposite direction of the steel strand bundling direction, the second sleeve is sleeved on the first sleeve and the second fiber grating, the wrapping tape is wound on the second sleeve, and the protection layer is sleeved on the wrapping tape.
Optionally, the first sleeve is a soft shrinkable sleeve.
Optionally, the second sleeve is a soft shrinkable sleeve.
Optionally, the wrapping tape is a high-strength fiber ribbon, and the wrapping tape is uniformly wound on the second sleeve.
Optionally, the second fibre grating is wound uniformly around the strand.
The invention has the beneficial effects that:
according to the invention, the second fiber bragg grating is wound along the opposite direction of the steel strand weaving direction, so that the grating area of the second fiber bragg grating is in close contact with the convex surface of the steel strand, and when radial pressure exists, the grating area of the second fiber bragg grating is further extruded, bent and deformed, so that a radial pressure signal is formed; in addition, the first fiber bragg grating is wound along the steel strand weaving direction, and the diameter of the optical fiber of the first fiber bragg grating is far smaller than that of the steel strand, so that the optical fiber between the two steel strands can not be interfered by external extrusion deformation, the temperature can be measured only, the temperature compensation can be performed on the second fiber bragg grating for measuring the radial force, and the higher precision is realized.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic structural diagram of a fiber grating-based temperature self-compensation omni-directional radial pressure sensing cable according to the present invention;
FIG. 2 is an enlarged schematic view of the first fiber grating of FIG. 1;
FIG. 3 is a schematic diagram of the structure of the outer cladding layer of FIG. 1;
wherein: 1-steel strand, 2-first fiber grating, 3-second fiber grating, 4-auxiliary winding belt, 5-outer cladding, 51-first sleeve, 52-second sleeve, 53-winding belt and 54-protective layer.
Detailed Description
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.
As shown in fig. 1 and fig. 2, an embodiment of the present invention provides a fiber grating-based temperature self-compensation omni-directional radial pressure sensing cable, which includes: the steel strand grating comprises a plurality of steel strands 1, a first fiber grating 2 and a second fiber grating 3, wherein the plurality of steel strands 1 are spirally bundled in the same direction to form strands, the first fiber grating 2 is wound on the outer surface of the strands along the bundling direction of the steel strands 1 and is positioned in gaps among the steel strands 1, the second fiber grating 3 is wound on the outer surface of the strands along the opposite direction of the bundling direction of the steel strands 1, the first fiber grating 2 is used for sensing and transmitting temperature signals, and the second fiber grating 3 is used for sensing and transmitting radial pressure signals of the steel strands 1.
According to the invention, the second fiber bragg grating 3 is wound along the opposite direction of the strand direction of the steel strand 1, so that the grating area of the second fiber bragg grating 3 is in close contact with the convex surface of the steel strand 1, and when radial pressure exists, the grating area of the second fiber bragg grating 3 is further extruded, bent and deformed, thereby forming a radial pressure signal; in addition, the first fiber bragg grating 2 is wound along the strand direction of the steel strands 1, and as the diameter of the optical fiber of the first fiber bragg grating 2 is far smaller than that of the steel strands 1, the optical fiber between the two steel strands 1 can not be interfered by external extrusion deformation, the measurement of temperature can be realized, the temperature compensation can be carried out on the second fiber bragg grating 3 for measuring the radial force, and the higher precision is realized.
Specifically, the steel strand 1 with high tensile strength and bending strength and good wear resistance is generally selected, and can bear large radial pressure without deformation, and the diameter variation of the steel strand 1 is small in the using process, and the diameter variation can be realized by changing the material and the processing technology of the steel wire in the steel strand 1.
Specifically, lubricating glue is coated in the gaps among the steel strands 1, and when the first fiber bragg grating 2 is arranged in the gaps among the steel strands 1, the lubricating glue can effectively reduce the friction resistance between the optical fibers and the steel wires. Because the first fiber bragg grating 2 is positioned in the gap between the steel strands 1, when the first fiber bragg grating 2 is subjected to external radial pressure, the first fiber bragg grating 2 cannot be subjected to radial pressure, so that the first fiber bragg grating 2 cannot generate signals due to the radial pressure, and the first fiber bragg grating 2 only generates signals due to temperature changes.
In the specific setting, the grating pitch on the first fiber grating 2 can be adjusted according to actual requirements, generally speaking, when the requirement on the detection precision is higher, the gratings on the first fiber grating 2 can be densely arranged, so that the gratings of the first fiber grating 2 and the gratings of the second fiber grating 3 are closer, and the temperature compensation effect is better.
Because the second fiber bragg grating 3 is wound along the opposite direction of the strand direction of the steel strands 1, the second fiber bragg grating 3 does not fall into gaps among the steel strands 1, and when external radial pressure is applied, the grating of the second fiber bragg grating 3 is directly extruded and deformed, so that the central wavelength is changed, and signals are generated.
In specific setting, the number of winding cycles of the second fiber grating 3 can be set according to actual conditions; the second fiber grating 3 with the same length has higher spatial resolution of radial pressure measurement when being wound more densely, but the measurement distance is shorter, so the relationship between the two needs to be considered comprehensively.
In specific setting, the number of the second fiber bragg gratings 3 is usually one, or may be multiple, and when there are multiple second fiber bragg gratings 3, the second fiber bragg gratings 3 are parallel to each other, so that intersection is avoided, and a detection result is not affected.
When the pressure cable is specifically arranged, the grating distance on the second fiber grating 3 can be adjusted according to actual requirements, and generally speaking, the pressure cable can have better measurement omnibearing performance by matching the number of winding cycles and the diameter of the steel strand.
In addition, the second fiber grating 3 needs to be wound uniformly as much as possible, and the uniform winding is the basis for accurate positioning of the pressure cable by using the grating, and the time is not dense and sparse.
Specifically, the optical fiber grating fixing device further comprises an auxiliary winding belt 4, the second optical fiber grating 3 is fixed on the auxiliary winding belt 4, the auxiliary winding belt 4 is wound on the outer surface of the strand along the opposite direction of the strand winding direction of the steel strand 1, the auxiliary winding belt 4 can prevent the second optical fiber grating 3 from slipping relative to the strand, and the second optical fiber grating 3 is facilitated to be uniformly wound relative to the steel strand 1.
Specifically, the fiber bragg grating protection device further comprises an outer cladding layer 5, wherein the outer cladding layer 5 is sleeved on the strand, the first fiber bragg grating 2 and the second fiber bragg grating 3, and the outer cladding layer 5 plays a role in protecting the first fiber bragg grating 2 and the second fiber bragg grating 3.
Further, the outer cladding 5 includes a first sleeve 51, a second sleeve 52, a wrapping tape 53 and a protection layer 54, the first sleeve 51 is sleeved on the strand and the first fiber grating 2, the second fiber grating 3 is wound on the outer surface of the first sleeve 51 along the direction opposite to the direction of the strand 1, the second sleeve 52 is sleeved on the first sleeve 51 and the second fiber grating 3, the wrapping tape 53 is wound on the second sleeve 52, and the protection layer 54 is sleeved on the wrapping tape 53.
The first sleeve 51 is a soft shrinkable sleeve, and after the first fiber grating 2 is mounted, the whole strand and the first fiber grating 2 are sleeved, so that the first fiber grating 2 is fixed, a soft contact surface with relatively large friction is provided for winding the second fiber grating 3, and fiber slippage is avoided in the process of winding the second fiber grating 3.
The second sleeve 52 is a soft shrinkable sleeve, and the whole of the strand is sleeved after the second fiber grating 3 is installed, so as to fix the second fiber grating 3 and provide a buffer room for the subsequent wrapping tape 53.
The wrapping belt 53 is a high-strength fiber ribbon, has high tensile strength, is wear-resistant, has certain flexibility, plays a role in dispersing external stress, and avoids damage to the optical fiber due to overlarge stress. The wrapping tape 53 tightly wraps the outer surface of the second sleeve 52, and further fixes the steel strand 1, the first fiber grating 2 and the second fiber grating 3. When the wrapping tape 53 is wound, the original positions of the first fiber bragg grating 2 and the second fiber bragg grating 3 are not changed without being driven; in addition, the degree of tightness of winding should be kept consistent as much as possible.
The protective layer 54 is made of a high-strength wear-resistant material, and plays a role in further protecting the first fiber grating 2 and the second fiber grating 3. In addition, the thickness of the protective layer 54 can be adjusted to change the pressure transmission coefficient according to different external radial pressure ranges, so as to adapt to the measurement range of the fiber grating.
The invention has the beneficial effects that:
1. according to the invention, the second fiber bragg grating is wound along the opposite direction of the steel strand weaving direction, so that the grating area of the second fiber bragg grating is in close contact with the convex surface of the steel strand, and when radial pressure exists, the grating area of the second fiber bragg grating is further extruded, bent and deformed, so that a radial pressure signal is formed; in addition, the first fiber bragg grating is wound along the steel strand weaving direction, and the diameter of the optical fiber of the first fiber bragg grating is far smaller than that of the steel strand, so that the optical fiber between the two steel strands can not be interfered by external extrusion deformation, the temperature can be measured only, the temperature compensation can be performed on the second fiber bragg grating for measuring the radial force, and the higher precision is realized.
2. The invention has no other electronic devices, small size, low cost and simple assembly, and can realize large-batch multi-scene application; for example, the pressure cable can be arranged on a tunnel slope to monitor the stability of the slope, and when the slope is loosened and displaced, the pressure cable can sense the change of the radial pressure of the pressure cable at a first time; in addition, the crack detector can be arranged in a building pillar or a building body to monitor the generation of cracks, once the cracks are generated, the radial pressure of surrounding concrete on the pressure cable can be changed, and therefore the monitoring and the positioning of the cracks of the building are achieved.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are also included in the scope of the present invention.
Claims (10)
1. The utility model provides an all-round radial pressure perception cable of temperature self-compensating based on fiber grating which characterized in that includes:
the steel strand is spirally bundled along the same direction to form a strand, the first fiber bragg grating is wound on the outer surface of the strand along the strand bundling direction and is positioned in a gap between the steel strands, the second fiber bragg grating is wound on the outer surface of the strand along the opposite direction of the strand bundling direction, the first fiber bragg grating is used for sensing and transmitting temperature signals, and the second fiber bragg grating is used for sensing and transmitting radial pressure signals of the steel strands.
2. The fiber grating-based temperature self-compensating omni-directional radial pressure sensing cable according to claim 1, wherein a lubricating glue is coated in the gaps between the steel strands.
3. The fiber grating-based temperature self-compensating omni-directional radial pressure sensing cable according to claim 2, wherein at least one of the second fiber gratings is parallel to each other when there are a plurality of the second fiber gratings.
4. The fiber grating-based temperature self-compensating omni-directional radial pressure sensing cable according to claim 1, further comprising an auxiliary winding tape, wherein the second fiber grating is fixed on the auxiliary winding tape, and the auxiliary winding tape is wound on the outer surface of the strand in the direction opposite to the strand binding direction of the steel strands.
5. The fiber grating-based temperature self-compensating omni-directional radial pressure sensing cable according to claim 1, further comprising an outer cladding layer covering the strand, the first fiber grating, and the second fiber grating.
6. The fiber grating-based temperature self-compensating omni-directional radial pressure sensing cable according to claim 5, wherein the outer covering layer comprises a first sleeve, a second sleeve, a wrapping tape and a protective layer, the first sleeve is sleeved on the strand and the first fiber grating, the second fiber grating is wound on the outer surface of the first sleeve along the direction opposite to the direction of the strand, the second sleeve is sleeved on the first sleeve and the second fiber grating, the wrapping tape is wound on the second sleeve, and the protective layer is sleeved on the wrapping tape.
7. The fiber grating-based temperature self-compensating omni-directional radial pressure sensing cable according to claim 6, wherein the first sleeve is a soft shrinkable sleeve.
8. The fiber grating-based temperature self-compensating omni-directional radial pressure sensing cable according to claim 6, wherein the second sleeve is a soft shrinkable sleeve.
9. The fiber grating-based temperature self-compensating omni-directional radial pressure sensing cable according to claim 6, wherein the wrapping tape is a high-strength fiber ribbon, and the wrapping tape is uniformly wound on the second sleeve.
10. The fiber grating-based temperature self-compensating omni-directional radial pressure sensing cable of claim 1, wherein the second fiber grating is uniformly wound around the strand.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210967921.XA CN115219082A (en) | 2022-08-12 | 2022-08-12 | Temperature self-compensation omnibearing radial pressure sensing cable based on fiber bragg grating |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210967921.XA CN115219082A (en) | 2022-08-12 | 2022-08-12 | Temperature self-compensation omnibearing radial pressure sensing cable based on fiber bragg grating |
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| CN202210967921.XA Pending CN115219082A (en) | 2022-08-12 | 2022-08-12 | Temperature self-compensation omnibearing radial pressure sensing cable based on fiber bragg grating |
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- 2022-08-12 CN CN202210967921.XA patent/CN115219082A/en active Pending
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