CN216284924U - Optical fiber sensor for monitoring aging of damping oil of viscous damper - Google Patents
Optical fiber sensor for monitoring aging of damping oil of viscous damper Download PDFInfo
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- CN216284924U CN216284924U CN202122200692.2U CN202122200692U CN216284924U CN 216284924 U CN216284924 U CN 216284924U CN 202122200692 U CN202122200692 U CN 202122200692U CN 216284924 U CN216284924 U CN 216284924U
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- 238000013016 damping Methods 0.000 title claims abstract description 97
- 239000013307 optical fiber Substances 0.000 title claims abstract description 79
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- 238000012544 monitoring process Methods 0.000 title claims abstract description 40
- 230000003287 optical effect Effects 0.000 claims abstract description 12
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- 238000004519 manufacturing process Methods 0.000 claims abstract description 8
- 229910001220 stainless steel Inorganic materials 0.000 claims description 13
- 239000010935 stainless steel Substances 0.000 claims description 13
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 9
- 229910052751 metal Inorganic materials 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 8
- 230000003595 spectral effect Effects 0.000 claims description 7
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- 229910052697 platinum Inorganic materials 0.000 claims description 5
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- 238000001228 spectrum Methods 0.000 abstract description 3
- 230000035945 sensitivity Effects 0.000 abstract description 2
- 230000007774 longterm Effects 0.000 abstract 1
- 238000005259 measurement Methods 0.000 abstract 1
- 239000003921 oil Substances 0.000 description 77
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- 230000007423 decrease Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
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- 239000003513 alkali Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
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- 229920000435 poly(dimethylsiloxane) Polymers 0.000 description 1
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- 238000006467 substitution reaction Methods 0.000 description 1
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Abstract
The invention belongs to the technical field of sensors, and discloses an optical fiber sensor for monitoring the aging degree of damping oil in a viscous damper. The sensor is based on a multi-beam interference principle, combines and utilizes the property that the optical refractive index of damping oil changes after the damping oil is aged, and indirectly monitors the aging degree of the damping oil in the viscous damper by monitoring the change of a Fabry-Perot cavity reflection spectrum signal under the condition of different aging degrees of the damping oil optical refractive index. The sensor can realize long-term, nondestructive and real-time monitoring of the aging degree of the damping oil in the viscous damper, has high measurement precision, and has the advantages of relatively simple manufacture, small volume, high strength, high sensitivity and the like. The sensor has wide application prospect and is easy to popularize.
Description
Technical Field
The invention relates to an optical fiber sensor for monitoring the aging degree of damping oil in a viscous damper, belongs to the technical field of sensors, and is particularly suitable for monitoring the aging degree of the damping oil in the viscous damper in a large bridge or a high-rise building.
Background
A damper is an dissipative vibration damping device arranged in a structure. The damper has the advantages of good damping effect, strong adaptability and the like, and is gradually applied to civil engineering structures to inhibit structural vibration caused by earthquakes and alleviate earthquake disasters.
Since the 80 s of the last century, viscous dampers have been used in civil engineering, and have had the advantage of "improving the damping ratio of structures without significantly changing the stiffness characteristics of the structures", the application of viscous dampers to engineering structures has reached a considerable scale for decades.
Although viscous dampers are various in form, the working principle is basically the same, as shown in the attached drawings: the energy input by earthquake or wind load forces the piston rod to move, the movement of the piston rod forces the damping oil in the cylinder barrel to flow through the damping hole in the piston, the damping oil flows to generate gap resistance so that the kinetic energy transmitted to the piston rod from the outside is converted into heat energy, and then the heat energy is transmitted to the external environment, so that the energy injected by earthquake or wind is dissipated.
According to the working principle of the viscous damper: when the piston rod is forced to move by the energy input from the outside, the temperature and the pressure inside the damping oil gradually rise. In addition, the viscous damper is often in a large temperature difference in the working environment. The viscosity of the damping fluid can be changed by factors such as large temperature difference and pressure: when the temperature rises or the pressure decreases, the distance between the damping liquid molecules increases, the cohesive force decreases, the viscosity of the damping liquid decreases, the aging of the damping liquid is caused, the damping force is directly reduced, and the failure of the viscous damper is further caused.
Once the damper fails, light: when earthquake or wind load comes, the damper can not exert the expected energy consumption and vibration reduction effect, and the unexpected damage of the structure is caused. The heavy load directly causes the failure and even collapse of the structure under the action of transverse loads such as earthquake or wind.
If the aging of the damping oil can be monitored earlier, and risk avoiding measures and diagnosis and repair of the viscous damper can be taken in time, the normal working probability of the viscous damper can be greatly improved, the safety of the structure is improved, and therefore economic loss and casualties caused by the failure of the viscous damper are reduced.
However, the viscous damper is often very large and complicated in installation process, and once installed on the structure, it is basically impossible to periodically disassemble and assemble the viscous damper for detecting the aging degree of the damping oil. Therefore, on the premise of not dismantling the viscous damper, the method has great significance in continuously and accurately monitoring the aging degree of the damping oil.
Therefore, the invention provides the optical fiber sensor which is pre-embedded in the viscous damper and continuously monitors the aging degree of damping oil in the viscous damper.
The optical fiber sensor has a series of advantages of small size, light weight, electromagnetic interference resistance, strong corrosion resistance, high monitoring precision, real-time continuous monitoring and the like, so that the optical fiber sensor has remarkable advantages in monitoring the aging degree of the damping oil in the viscous damper, and is expected to provide a brand-new idea and method for the current monitoring technology of the aging degree of the damping oil in the viscous damper.
Disclosure of Invention
In order to solve the technical problem, the invention provides an optical fiber sensor for monitoring the aging degree of damping oil in a viscous damper, which is characterized in that the sensor is very sensitive to the change of the optical refractive index of the damping oil, and the aging degree of the damping oil can be indirectly monitored through the change of the optical refractive index of the damping oil. The sensor for monitoring the aging degree of the damping oil based on the Fabry-Perot cavity is simple to manufacture, and can monitor the aging degree of the damping oil in the viscous damper in real time without damage, so that the performance state of the viscous damper is reasonably evaluated, the normal performance of the vibration damping effect of the viscous damper is ensured, and the safety of the structure is further ensured.
The technical scheme of the invention is as follows:
the optical fiber sensor for monitoring the aging degree of the damping oil of the viscous damper is characterized by comprising a single-mode optical fiber (1), a stainless steel shell (2), an oil inlet small hole (3) and a light reflecting end face (4);
the reflecting end face (4) is formed by polishing or sticking a reflecting mirror face to the end face of one end of a metal rod (8) connected with the sensor;
the stainless steel shell (2) is provided with enough oil inlet holes (3) to ensure that damping oil outside the optical fiber sensor flows into and out of the optical fiber sensor fully;
the single-mode optical fiber (1), the reflecting end face (4) and damping oil (5) entering the sensor form a platinum cavity;
the single-mode optical fiber (1) is used as an input/output optical fiber, is fixed by an optical fiber ceramic ferrule (6), and is inserted into the optical fiber sensor through a through hole where the sealing ring (7) is located;
after damping oil in the viscous damper continuously flows into and flows out of the optical fiber sensor through the oil inlet small holes (3) and forms a platinum cavity with the single-mode optical fiber (1) and the reflecting end face (4), once the damping oil (5) is aged, the light refractive index of the damping oil can be changed, spectral signals in an optical fiber demodulator connected with the optical fiber (1) are further caused to be changed, and the aging degree of the damping oil to be measured is further reflected.
The optical fiber sensor for monitoring the aging degree of the damping oil of the viscous damper is characterized in that the size and the number of the oil inlet small holes (3) can be adjusted according to different specific conditions of different viscous dampers on the basis of ensuring that the damping oil can fully flow into and flow out of the sensor.
The optical fiber sensor for monitoring the aging degree of the damping oil of the viscous damper is characterized in that the specific implementation method and the size of the reflecting end face (4) can be adjusted according to the manufacturing process and the specific monitoring requirement of the sensor.
The optical fiber sensor for monitoring the aging degree of the damping oil of the viscous damper is characterized in that the distance between an optical fiber and a reflecting end face (4) can be adjusted according to different monitoring conditions and requirements under the condition of ensuring optical signal transmission.
The optical fiber sensor for monitoring the aging degree of the damping oil of the viscous damper is characterized in that a single-mode optical fiber (1) penetrates through a piston rod of the viscous damper, is fixed on the piston rod and embedded into the viscous damper, is externally connected with an optical fiber demodulator, and continuously monitors the change of a spectrum signal.
The working principle of the invention is as follows:
the principle of the optical fiber sensor for monitoring the aging degree of the damping oil of the viscous damper is shown in a schematic diagram, and due to the existence of oil inlet small holes with enough quantity and size on a sensor shell, the damping oil can be ensured to fully flow into and flow out of the sensor, so that the damping oil in the optical fiber sensor (namely the damping oil forming a medium part of a platinum cavity) and the damping oil in the viscous damper can be considered to be same in nature in real time.
The optical refractive index of the viscous damper can be changed along with the continuous aging of the damping oil in the viscous damper.
Changes in the optical refractive index cause changes in the shape of the spectrogram obtained by the fiber optic demodulator. The Free Spectral Range (FSR) in the spectrogram and the optical refractive index n of the damping oil have the following relationship:
where n is the refractive index of the medium, λ is the wavelength of the light, and L is the cavity length. Under the working condition of the invention, the medium is damping oil, and n is the refractive index of the damping oil. It can be further deduced that:
therefore, the change Δ n of the optical refractive index of the damping oil can be deduced according to the FSR in the spectrum returned by the sensor continuously obtained from the spectrometer, thereby deducing the aging condition of the damping oil in the viscous damper.
The invention has the beneficial effects that:
(1) the invention combines the property of the change of the optical refractive index of the Fabry-Perot cavity and the damping oil caused by the aging of the damping oil, so that the invention has higher sensitivity.
(2) The invention can realize continuous real-time monitoring of the aging degree of the damping oil in the viscous damper.
(3) The invention has small volume, can be embedded into the viscous damper to be tested without influencing the normal work of the viscous damper, and realizes the nondestructive monitoring of the aging degree of the damping oil.
(4) The invention adopts the demodulator to calculate the aging degree of the damping oil from the spectrogram, has strong anti-interference performance and more accurate monitoring result.
(5) The invention has the advantages of relatively simple manufacture, convenient use, reasonable manufacturing cost, suitability for popularization and higher application prospect.
Drawings
FIG. 1 is a schematic view of a sensor according to the present invention;
FIG. 2 is a schematic interior elevational view of the present invention;
FIG. 3 is a schematic external view of the present invention;
FIG. 4 is a top view of the present invention;
FIG. 5 is a schematic diagram of the operation of the present invention;
FIG. 6 is a schematic view of a sensor arrangement according to the present invention;
in fig. 1 to 5: (1) a single mode optical fiber; (2) a stainless steel housing; (3) oil inlet holes; (4) a light-reflecting end face; (5) damping oil; (6) an optical fiber ceramic ferrule; (7) a seal ring; (8) a metal rod;
in fig. 6: (9) a piston rod; (10) an optical fiber hole 1; (11) a fiber hole 2; (12) a sensor; (13) a piston; (14) a damping hole; (15) damping oil in the damper; (16) a piston cylinder; (17) an external connector.
Detailed Description
In order to make the objects, features and advantages of the present invention more intuitive and understandable, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention, and it is obvious that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in a schematic diagram, the optical fiber sensor for monitoring the aging degree of the damping oil of the viscous damper comprises a single-mode optical fiber (1), a stainless steel shell (2), an oil inlet small hole (3) and a light reflecting end face (4);
the reflecting end face (4) is formed by polishing and grinding one end face of a metal rod (8) connected with the sensor;
the stainless steel shell (2) is provided with enough oil inlet holes (3) to ensure that damping oil outside the optical fiber sensor flows into and out of the optical fiber sensor fully;
the single-mode optical fiber (1), the reflecting end face (4) and damping oil (5) entering the sensor form a Fabry-Perot cavity;
the single-mode optical fiber (1) is used as an input/output optical fiber, is supported by the optical fiber ceramic ferrule (6), and is inserted into the optical fiber sensor through a through hole where the sealing ring (7) is located;
an optical fiber sensor of monitoring viscous damper damping oil ageing degree, the size and the quantity of oil feed aperture (3) can be according to the difference of different viscous damper particular cases and adjust guaranteeing under the prerequisite that damping oil can fully flow in the outflow sensor.
The specific implementation method and size of the reflecting end face (4) of the optical fiber sensor for monitoring the aging degree of the damping oil of the viscous damper can be adjusted according to the manufacturing process and the specific monitoring requirements of the sensor.
According to the optical fiber sensor for monitoring the aging degree of the damping oil of the viscous damper, under the condition of ensuring optical signal transmission, the distance between an optical fiber and the reflecting end face (4) can be adjusted according to different conditions and requirements of monitoring work.
A monitoring viscous damper damping oil ageing degree's optical fiber sensor, behind the single mode fiber (1) of sensor passed viscous damper piston rod to be fixed in on the piston rod, bury in the viscous damper, external optic fibre demodulation appearance lasts the change of monitoring spectral signal.
The method comprises the following steps: taking a stainless steel block with a proper size, grinding the stainless steel block by using a machine according to a schematic diagram to manufacture a circular plate with a metal rod, and polishing and grinding the small end face of the metal rod.
Step two: a cylindrical hollow stainless steel shell is manufactured by using a machine tool according to the shape shown in the schematic diagram, the size of the bottom surface is matched with that of the first round plate, and the bottom surface of one side is opened (the bottom surface is ready to be spliced with the first round plate).
Step three: and opening and closing oil inlet small holes with proper quantity and size and an optical fiber hole with proper size on the stainless steel shell in the second step by combining the schematic diagram. So as to ensure that the damping oil can fully flow into and out of the sensor in the future and the optical fiber can smoothly extend into the sensor through the stainless steel shell.
Step four: and (3) combining the schematic diagram, splicing the circular plate manufactured in the first step with the stainless steel shell after the third step (the specific splicing mode can adopt welding, mechanical connection and other modes, but attention must be paid to protecting the reflecting end face and ensuring the reflecting effect of the reflecting end face), and paying attention to the fact that the reflecting end face of the metal rod faces the optical fiber hole.
Step five: and (3) taking a single-mode optical fiber, penetrating the single-mode optical fiber through the optical fiber ceramic ferrule, and penetrating the optical fiber ceramic ferrule through the reserved optical fiber hole to ensure that the single-mode optical fiber is aligned with the light-reflecting end face of the metal rod spliced in the step four. And sealing the prepared hole by using a sealing ring in combination with the schematic diagram.
Step six: a container with a proper size is taken in a laboratory, and a proper amount of damping oil (common damping oil in the viscous damper comprises hydraulic oil, methyl silicone oil and the like, and can be adjusted according to the actual condition of the viscous damper to be monitored) with proper depth is poured into the container. The finished sensor is placed in the container containing the damping oil, and the damping oil is required to completely submerge the sensor. The sensor is externally connected with an optical fiber demodulator, and then the damping oil is continuously stirred by using a machine. In the process, the spectral signal deviation and the damping oil aging degree are continuously recorded (the damping oil aging degree can be detected by adopting a traditional method such as alkali equivalent analysis and the like). And the calibration of the sensor laboratory is completed by establishing the relationship between the aging degree of the damping oil and the spectral signal offset of the sensor.
Step seven: according to the schematic diagram, a calibrated sensor penetrates through a piston rod and is embedded into a specific viscous damper needing to monitor the aging degree of damping oil, and the sensor is fixed on the piston rod in combination with the schematic diagram (the fixing mode can be mechanical connection, bonding, welding and the like, can be freely selected according to the situation, but the fixing process needs to protect the sensor and cannot influence the normal work of the sensor, and needs to seal an optical fiber hole). And the optical fiber is externally connected with a demodulator to monitor the aging degree of the damping oil in the viscous damper.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (5)
1. The optical fiber sensor for monitoring the aging of the damping oil of the viscous damper is characterized by comprising a single-mode optical fiber (1), a stainless steel shell (2), an oil inlet small hole (3) and a light reflecting end face (4);
the reflecting end face (4) is formed by polishing and grinding one end face of a metal rod (8) connected with the sensor;
the stainless steel shell (2) is provided with enough oil inlet holes (3) to ensure that damping oil outside the optical fiber sensor flows into and out of the optical fiber sensor fully;
the single-mode optical fiber (1), the reflecting end face (4) and damping oil (5) entering the sensor form a platinum cavity;
the single-mode optical fiber (1) is used as an input/output optical fiber, is supported by the optical fiber ceramic ferrule (6), and is inserted into the optical fiber sensor through a through hole where the sealing ring (7) is located;
after damping oil in the viscous damper continuously flows into and flows out of the optical fiber sensor through the oil inlet small holes (3) and forms a platinum cavity with the single-mode optical fiber (1) and the reflecting end face (4), once the damping oil (5) is aged, the light refractive index of the damping oil can be changed, spectral signals in an optical fiber demodulator connected with the single-mode optical fiber (1) are further changed, and the aging degree of the damping oil to be measured is reflected.
2. The optical fiber sensor for monitoring the aging of the damping oil of the viscous damper as claimed in claim 1, wherein the size and the number of the oil inlet holes (3) can be adjusted according to the specific conditions of the viscous damper on the premise of ensuring that the damping oil can fully flow into and out of the sensor.
3. An optical fiber sensor for monitoring the aging of the damping oil of a viscous damper, according to claim 1, characterized in that the specific implementation method and size of the reflecting end face (4) can be adjusted according to the manufacturing process and specific monitoring requirements of the sensor.
4. An optical fiber sensor for monitoring the aging of damping oil of a viscous damper, according to claim 1, characterized in that the distance between the optical fiber and the reflecting end face (4) can be adjusted according to different conditions and requirements of monitoring operation under the condition of ensuring the transmission of optical signals.
5. The optical fiber sensor for monitoring the aging of the damping oil of the viscous damper as claimed in claim 1, wherein the single mode optical fiber (1) of the sensor is fixed on the piston rod after passing through the piston rod of the viscous damper, embedded in the viscous damper, externally connected with an optical fiber demodulator, and continuously monitors the change of the spectral signal.
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| CN114002186A (en) * | 2021-09-13 | 2022-02-01 | 大连理工大学 | Optical fiber sensor for monitoring aging of damping oil of viscous damper |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114002186A (en) * | 2021-09-13 | 2022-02-01 | 大连理工大学 | Optical fiber sensor for monitoring aging of damping oil of viscous damper |
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