CN111174954A - Online monitoring device and method for stress of stud - Google Patents
Online monitoring device and method for stress of stud Download PDFInfo
- Publication number
- CN111174954A CN111174954A CN202010143025.2A CN202010143025A CN111174954A CN 111174954 A CN111174954 A CN 111174954A CN 202010143025 A CN202010143025 A CN 202010143025A CN 111174954 A CN111174954 A CN 111174954A
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- CN
- China
- Prior art keywords
- stress
- fiber sensor
- stud
- optical fiber
- demodulator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
- 238000000034 method Methods 0.000 title claims abstract description 12
- 238000012806 monitoring device Methods 0.000 title claims abstract description 9
- 239000013307 optical fiber Substances 0.000 claims abstract description 44
- 230000003287 optical effect Effects 0.000 claims abstract description 32
- 230000008859 change Effects 0.000 claims abstract description 22
- 238000012544 monitoring process Methods 0.000 claims description 7
- 239000000835 fiber Substances 0.000 claims description 5
- 238000011065 in-situ storage Methods 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 abstract description 2
- 238000005259 measurement Methods 0.000 abstract description 2
- 230000035882 stress Effects 0.000 description 22
- 208000037656 Respiratory Sounds Diseases 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000006353 environmental stress Effects 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000003252 repetitive effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
Images
Classifications
-
- 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
- G01L1/242—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 the material being an optical fibre
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/24—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for determining value of torque or twisting moment for tightening a nut or other member which is similarly stressed
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Arrangements For Transmission Of Measured Signals (AREA)
Abstract
The invention discloses an on-line monitoring device and a method for stress of a stud bolt. The demodulator demodulates the optical wavelength change of the optical fiber sensor, converts the optical wavelength change into an analog signal, converts the analog signal into a digital signal, sends the digital signal to the local server, and the local server converts the digital signal of the demodulator into stress data of the stud according to the relation between the stress calibrated by the optical fiber sensor and the optical wavelength change and stores the stress data into a database. And the remote client reads the data in the server in real time, judges the stress state of the stud and monitors the stress of the stud in real time. The invention adopts full-optical measurement transmission, is not interfered by electromagnetic signals, can monitor the stress of the stud on line in real time and improves the safety of running equipment of a hydraulic power plant.
Description
Technical Field
The invention relates to the technical field of data monitoring, in particular to an online monitoring device and method for stress of a stud.
Background
Be applied to the stud connection of hydroelectric power plant equipment, its operational environment often is complicated and abominable, and the stud that is used for especially connecting big part can produce fatigue, the crackle appears even under the repetitive action of alternating load and environmental stress, and the condition that the fracture can lead to the stud to appear in the continuation expansion of crackle to bring serious safety risk to the part of stud connection and even whole mechanical device.
At present, the fastening state of the nut and the bolt can be judged by utilizing the deformation of the elastic washer in the shape of the annular cylinder, and the fastening force between the nut and the bolt is measured by the deformation of the test strain gauge adhered on the elastic washer. And in the process of screwing the bolt, reading and recording signal data measured by the test strain gauge according to a preset screwing turn interval, and establishing a relation between the screwing turn and a signal data value until the bolt is completely screwed. And when the signal data measured by the strain gauge is smaller than a preset threshold value, the fastening state of the nut is considered to have a problem.
The method has the following disadvantages: the elastic washer sensor is high in height and large in diameter, and is not suitable for being additionally installed on the existing structure. And many structures can not install additional at all, and the use occasion receives very big restriction.
Disclosure of Invention
The present invention is directed to provide an apparatus and a method for online monitoring of stud stress.
In order to achieve the above object, the present disclosure provides an online monitoring device for stress of a stud, including:
an optical fiber sensor; blind holes are radially arranged on the stud bolts, and the optical fiber sensors are arranged in the blind holes;
the laser is used for sending to the optical fiber sensor; a demodulator for converting the wavelength change of the optical fiber sensor into an analog signal and converting the analog signal into a digital signal;
a beam splitter for distributing laser light to the fiber sensor and for transmitting a change in wavelength of light of the fiber sensor to the demodulator;
the optical fiber sensor is in signal connection with the demodulator through the optical splitter;
a local server; the local server is provided with a relational model of the stress of the optical fiber sensor and the change of the optical wavelength, and the local server for receiving the digital signals is in signal connection with the demodulator;
a remote client; the remote client is in signal connection with the local server.
The online monitoring method for the stress of the stud is also provided, and is applied to the online monitoring device, and the online monitoring method comprises the following steps:
the optical fiber sensor is arranged in a blind hole which is radially arranged in the stud, and the stress of the stud is converted into the change of the optical wavelength;
the optical splitter distributes the laser sent by the demodulator to each optical fiber sensor and simultaneously transmits the change of the optical wavelength of each optical fiber sensor to the demodulator;
the demodulator demodulates the optical wavelength variation of the optical fiber sensor, converts the optical wavelength variation into an analog signal, converts the analog signal into a digital signal and sends the digital signal to an on-site server;
the in-situ server converts the digital signal of the demodulator into stress data of the stud according to the established relation model of the stress of the optical fiber sensor and the change of the optical wavelength, and stores the stress data into a database;
and the remote client reads the data in the server in real time and judges the stress state of the stud.
The invention has the beneficial effects that:
the invention adopts full-optical measurement transmission, is not interfered by electromagnetic signals, can monitor the stress of the stud on line in real time and improves the safety of running equipment of a hydraulic power plant.
Drawings
The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:
FIG. 1 is a schematic view of a fiber optic sensor installation according to the present invention;
FIG. 2 is a flow chart of an online force monitoring method for a stud according to the present invention.
Description of the reference numerals
1-double-end stud, 2-blind hole and 3-optical fiber sensor.
Detailed Description
The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.
The invention relates to an on-line monitoring device for stress of a stud, which comprises:
an optical fiber sensor; as shown in fig. 1, the stud is provided with a blind hole in the radial direction, and the optical fiber sensor is installed in the blind hole.
The optical fiber sensor is manufactured based on the Bragg grating, and the interface can be round or square after being packaged; before use, after packaging, calibration is required to obtain the relationship between the change of optical wavelength and strain.
Meanwhile, the optical fiber sensor is fixed in the blind hole in the center of the stud, the blind hole can be completely filled with glue, the two ends of the optical fiber sensor can be respectively fixed, and the optical fiber sensor and the stud can be integrated into a whole by adopting threaded fixation.
The demodulator is used for converting wavelength change of the optical fiber sensors into analog signals and converting the analog signals into digital signals, and the demodulator can demodulate received optical signals into digital signals and can synchronously acquire a plurality of optical fiber sensors.
The optical splitter is used for distributing laser to the optical fiber sensor and transmitting the change of the optical wavelength of the optical fiber sensor to the demodulator, can transmit optical signals in two directions between the optical fiber sensor and the demodulator, can be connected in parallel or in series, and realizes large-scale networking of the optical fiber sensor.
The optical fiber sensor is in signal connection with the demodulator through the optical splitter.
A local server; the local server can convert the received digital signals from the demodulator into the stress of the stud and has a database storage function. The local server is provided with a relation model of the stress of the optical fiber sensor and the change of the optical wavelength, and the local server for receiving the digital signal is in signal connection with the demodulator.
A remote client; the remote client can read the data of the local server and judge the stress state of the stud. The remote client is in signal connection with the local server.
The invention relates to an online monitoring method for stress of a stud, which comprises the following steps as shown in figure 2:
the optical fiber sensor is arranged in a blind hole which is radially arranged in the stud, and the stress of the stud is converted into the change of the optical wavelength;
the optical splitter distributes the laser sent by the demodulator to each optical fiber sensor and simultaneously transmits the change of the optical wavelength of each optical fiber sensor to the demodulator;
the demodulator demodulates the optical wavelength variation of the optical fiber sensor, converts the optical wavelength variation into an analog signal, converts the analog signal into a digital signal and sends the digital signal to an on-site server;
the in-situ server converts the digital signal of the demodulator into stress data of the stud according to the established relation model of the stress of the optical fiber sensor and the change of the optical wavelength, and stores the stress data into a database;
and the remote client reads the data in the server in real time and judges the stress state of the stud.
The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.
It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.
In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.
Claims (2)
1. An on-line monitoring device for stress of a double-end stud is characterized by comprising:
an optical fiber sensor; blind holes are radially arranged on the stud bolts, and the optical fiber sensors are arranged in the blind holes;
the laser is used for sending to the optical fiber sensor; a demodulator for converting the wavelength change of the optical fiber sensor into an analog signal and converting the analog signal into a digital signal;
a beam splitter for distributing laser light to the fiber sensor and for transmitting a change in wavelength of light of the fiber sensor to the demodulator;
the optical fiber sensor is in signal connection with the demodulator through the optical splitter;
a local server; the local server is provided with a relational model of the stress of the optical fiber sensor and the change of the optical wavelength, and the local server for receiving the digital signals is in signal connection with the demodulator;
a remote client; the remote client is in signal connection with the local server.
2. An online monitoring method for stress of a stud is applied to the online monitoring device of claim 1, and is characterized by comprising the following steps:
the optical fiber sensor is arranged in a blind hole which is radially arranged in the stud, and the stress of the stud is converted into the change of the optical wavelength;
the optical splitter distributes the laser sent by the demodulator to each optical fiber sensor and simultaneously transmits the change of the optical wavelength of each optical fiber sensor to the demodulator;
the demodulator demodulates the optical wavelength variation of the optical fiber sensor, converts the optical wavelength variation into an analog signal, converts the analog signal into a digital signal and sends the digital signal to an on-site server;
the in-situ server converts the digital signal of the demodulator into stress data of the stud according to the established relation model of the stress of the optical fiber sensor and the change of the optical wavelength, and stores the stress data into a database;
and the remote client reads the data in the server in real time and judges the stress state of the stud.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010143025.2A CN111174954A (en) | 2020-03-04 | 2020-03-04 | Online monitoring device and method for stress of stud |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010143025.2A CN111174954A (en) | 2020-03-04 | 2020-03-04 | Online monitoring device and method for stress of stud |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111174954A true CN111174954A (en) | 2020-05-19 |
Family
ID=70647135
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010143025.2A Pending CN111174954A (en) | 2020-03-04 | 2020-03-04 | Online monitoring device and method for stress of stud |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111174954A (en) |
-
2020
- 2020-03-04 CN CN202010143025.2A patent/CN111174954A/en active Pending
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