Stress monitoring device based on fiber grating sensor

Abstract

The utility model discloses a stress monitoring device based on a fiber bragg grating sensor, and relates to the technical field of fiber bragg grating sensors, in particular to the stress monitoring device based on the fiber bragg grating sensor, which is used for monitoring the stress of a supporting beam or a supporting column to be monitored and comprises a fiber bragg grating demodulator. The fiber grating sensor comprises a mounting shell, two sensing assemblies and the like, one end, with a certain length, of a supporting strip in each sensing assembly is fixedly connected with a supporting beam column, a certain distance exists between the fixed end of the supporting strip and the mounting shell, the supporting strip is tightly attached to the supporting beam column, and when the supporting beam column generates stress changes such as vibration and displacement, the supporting beam column is tightly attached to the mounting shell. The supporting strip is locally bent under the influence of the stress, the stress strip located in the supporting strip displaces, the elastic element is pulled when the stress strip displaces, the stress borne by the elastic element acts on the optical grating, the wavelength of the optical grating changes, and therefore monitoring of large-range stress changes of the supporting beam column is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of optical fiber grating sensors, in particular to a stress monitoring device based on optical fiber grating sensors. Background Art

[0002] Fiber Bragg grating sensors are used to detect external intrusion vibration signals and are the core equipment for signal acquisition. Fiber Bragg grating sensors need to be installed in places where vibrations can be detected in order to effectively and accurately collect intrusion vibration signals.

[0003] Coal mines are reasonable spaces dug by humans when digging geological layers rich in coal, usually including tunnels, shafts, and mining faces, etc. Since the mine is underground, it is full of instability, so fiber grating sensors are installed inside the mine to monitor the specific conditions of each part. However, when fiber grating sensors monitor the stress changes of supporting beams inside the mine, due to the relatively small stress sensing range of fiber grating sensors on the current market, a large number of fiber grating sensors are needed to monitor the stress of supporting beams in the mine, which greatly increases the cost.

[0004] In the published Chinese patent application, publication number: CN211200494U, patent name: A cofferdam support stress monitoring device based on fiber grating, although the prior art uses fiber grating sensors to measure stress values. However, when the prior art monitors the stress of a single support beam, two mutually perpendicular fiber grating sensors are required to cooperate to detect the stress changes of the support beam. Using this method to detect the stress of the support beam increases the number of fiber grating sensors and also increases the equipment cost.

[0005] In summary, in order to solve the problems existing in the prior art, this case is proposed to solve them. Utility Model Content

[0006] 1. Technical issues to be resolved

[0007] In view of the deficiencies of the prior art, the utility model provides a stress monitoring device based on a fiber grating sensor, which solves the problems raised in the above background technology.

[0008] (II) Technical solution

[0009] To achieve the above objectives, the utility model is implemented through the following technical solutions: a stress monitoring device based on a fiber grating sensor, which is used to monitor the stress of a support beam or a support column for monitoring, including a fiber grating demodulator and at least one fiber grating sensor installed on the support beam or the support column for monitoring, wherein the fiber grating demodulator is communicatively connected with the at least one fiber grating sensor;

[0010] The fiber grating sensor comprises an armored optical cable, an outer shell, an elastic element, a mounting shell, and two sensing components; one end of the armored optical cable passes through the outer shell, and a grating is engraved on the exposed portion of the end of the armored optical cable, and one end of the elastic element is fixedly connected to the grating; the outer shell is fixedly mounted on a side wall of the mounting shell, the mounting shell is in the shape of a disk as a whole, and a sliding groove is provided on the side wall of the mounting shell where the circumference is located;

[0011] The sensing component includes a stress bar and a support bar with a certain length. The support bar is slidably connected to the mounting shell through a slide groove. A through groove is opened inside the support bar along the length direction. The stress bar is inserted in the through groove of the support bar, and one end of the stress bar is fixedly connected to the inner wall of the end of the support bar away from the mounting shell, and the other end of the stress bar is rotatably connected to the elastic element; the mounting shell is fixedly installed on a support beam or support column for monitoring, and the end of the support bar away from the mounting shell is fixedly installed on the support beam or support column for monitoring, and the support bar is in a stretched state.

[0012] Optionally, the outer sleeve of the grating is provided with an inner shell covering it, one end of the elastic element is located inside the inner shell, and the elastic element is fixedly connected to the grating by an adhesive.

[0013] Optionally, a heat insulation layer is provided on the outside of the inner shell, and the heat insulation layer is composed of a ceramic silicone rubber layer and an aerogel felt layer.

[0014] Optionally, a connector is installed on the outer shell, and the armored optical cable is fixedly installed on the outer shell through the connector.

[0015] Optionally, the support bar is made of aluminum material.

[0016] Optionally, the elastic element is in a cantilever beam structure as a whole, the elastic element is made of a metal sheet, and a plurality of vacuum cavities are arranged inside the elastic element.

[0017] (III) Beneficial effects

[0018] The utility model provides a stress monitoring device based on a fiber grating sensor, which has the following beneficial effects:

[0019] 1. A stress monitoring device based on a fiber grating sensor has the effect of expanding the monitoring range of stress changes of supporting beams and columns through the coordinated setting of a fiber grating sensor and a fiber grating demodulator. The fiber grating sensor includes a mounting shell, two sensing components, etc. One end of a support bar with a certain length in the sensing component is fixedly connected to the supporting beam, and there is a certain distance between the fixed end of the support bar and the mounting shell, and the support bar is in close contact with the supporting beam. When the supporting beam undergoes stress changes such as vibration and displacement, the support bar is locally bent by the influence of such stress, and the stress bar inside the support bar is displaced. When the stress bar is displaced, the elastic element is pulled, and the stress on the elastic element acts on the grating, and the grating wavelength changes, thereby realizing the monitoring of a large range of stress changes of the supporting beam.

[0020] 2. Through the cooperation of two sensing components, the stress changes of the support beam or support column can be monitored simultaneously. The support bars in the two sensing components are fixedly installed on the support beam and the support column respectively. When the support beam and the support column undergo stress changes such as misalignment and movement, the fiber grating sensor can timely monitor such stress changes, thereby expanding the monitoring range of stress changes of the support beam and the support column, avoiding the use of multiple fiber grating sensors, reducing the number of fiber grating sensors used, and reducing equipment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0022] Figure 1 It is a front view structural schematic diagram of a fiber Bragg grating sensor in a stress monitoring device based on a fiber Bragg grating sensor of the utility model;

[0023] Figure 2 It is a cross-sectional structural schematic diagram of a fiber Bragg grating sensor in a stress monitoring device based on a fiber Bragg grating sensor of the utility model;

[0024] Figure 3 for Figure 2 The enlarged structural diagram at A in the middle;

[0025] Figure 4 It is a schematic diagram of the top view structure of a fiber Bragg grating sensor in a stress monitoring device based on a fiber Bragg grating sensor of the utility model;

[0026] Figure 5It is a schematic diagram of the structure of the fiber grating sensor in the utility model after being installed on the support beam for monitoring.

[0027] In the figure: 1. outer shell; 2. mounting shell; 3. support bar; 4. connector; 5. armored optical cable; 6. stress bar; 7. elastic element; 8. thermal insulation layer; 9. inner shell; 10. support beam; 11. support column; 12. first bolt; 13. grating; 14. first mounting hole; 15. second mounting hole; 16. second bolt. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indications or implications.

[0029] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments.

[0030] See also Figures 1 to 5 The utility model provides a technical solution: a stress monitoring device based on a fiber grating sensor, which is used to monitor the stress of a support beam 10 or a support column 11 for monitoring, including a fiber grating demodulator and at least one fiber grating sensor installed on the support beam 10 or the support column 11 for monitoring, and the fiber grating demodulator is communicatively connected to the at least one fiber grating sensor.

[0031] The fiber Bragg grating sensor detects stress, and the fiber Bragg grating demodulator is used for stress data collection. When the support beam 10 or the support column 11 undergoes stress changes such as vibration and displacement, the fiber Bragg grating sensor detects the stress and transmits the relevant data to the fiber Bragg grating demodulator.

[0032] The fiber grating sensor comprises an armored optical cable 5, an outer shell 1, an elastic element 7, a mounting shell 2, and two sensing components. One end of the armored optical cable 5 passes through the outer shell 1, and a grating 13 is engraved on the exposed part of the end of the armored optical cable 5, and one end of the elastic element 7 is fixedly connected to the grating 13; the outer shell 1 is fixedly mounted on a side wall of the mounting shell 2, and the mounting shell 2 is in the shape of a disk as a whole, and a sliding groove is provided on the side wall of the mounting shell 2 where the circumference is located.

[0033] Among them, the two sensing components are used to expand the contact range with the support beam column. When the support beam 10 or the support column 11 undergoes stress changes such as vibration and displacement, the stress is transmitted to the elastic element 7 through the sensing components. The stress on the elastic element 7 acts on the grating 13, and the wavelength of the grating 13 changes. The mounting shell 2 is used to facilitate the fixing and mounting of the entire fiber grating sensor on the support column 11 or the support beam 10.

[0034] The sensing component includes a stress bar 6 and a support bar 3 with a certain length. The support bar 3 is slidably connected to the mounting shell 2 through a slide groove. A through groove is opened inside the support bar 3 along the length direction. The stress bar 6 is inserted in the through groove of the support bar 3, and one end of the stress bar 6 is fixedly connected to the inner wall of the end of the support bar 3 away from the mounting shell 2, and the other end of the stress bar 6 is rotatably connected to the elastic element 7; the mounting shell 2 is fixedly installed on the support beam 10 or support column 11 for monitoring, and the end of the support bar 3 away from the mounting shell 2 is fixedly installed on the support beam 10 or support column 11 for monitoring, and the support bar 3 is in a stretched state.

[0035] Among them, the support bar 3 is slidably connected with the mounting shell 2 through a slide groove, which is convenient for adjusting the angle between the two sensing components and the mounting shell 2, that is, the two support bars 3 can form a certain angle after rotation, so as to facilitate the fixing of the entire fiber grating sensor at the junction of the support beam 10 and the support column 11, and facilitate the monitoring of the stress at the junction of the support beam 10 and the support column 11. The fiber grating sensor includes a mounting shell 2, two sensing components, etc., one end of a support bar 3 with a certain length in the sensing component is fixedly connected to the support beam column, there is a certain distance between the fixed end of the support bar 3 and the mounting shell 2, and the support bar 3 is closely attached to the support beam column. When the support beam column vibrates, moves, and other stress changes occur, the support bar 3 is locally bent by such stress, and the stress bar 6 located inside the support bar 3 is pulled and deviated. When the stress bar 6 deviates, it pulls the elastic element 7, and the stress on the elastic element 7 acts on the grating 13, and the wavelength of the grating 13 changes, thereby realizing the monitoring of a large range of stress changes in the support beam column.

[0036] Specifically, the outer portion of the grating 13 is covered with an inner shell 9 , one end of the elastic element 7 is located inside the inner shell 9 , and the elastic element 7 is fixedly connected to the grating 13 via an adhesive.

[0037] The inner housing 9 is used to protect the grating 13. After the elastic element 7 is fixedly connected to the grating 13, its stress can effectively act on the grating 13.

[0038] More specifically, a heat insulation layer 8 is provided outside the inner shell 9 , and the heat insulation layer 8 is composed of a ceramic silicone rubber layer and an aerogel felt layer.

[0039] The heat insulation layer 8 is used to prevent the external temperature from invading the grating 13, so as to avoid the temperature from affecting the grating 13. The ceramic silicone rubber layer and the aerogel felt layer are both used for heat insulation.

[0040] Specifically, a connector 4 is installed on the outer shell 1 , and the armored optical cable 5 is fixedly installed with the outer shell 1 through the connector 4 .

[0041] The connector 4 is used to fix the armored optical cable 5 to the outer shell 1 .

[0042] Specifically, the support bar 3 is made of aluminum material.

[0043] The support bar 3 is made of aluminum material, which is convenient for deformation after being stressed. The rigidity of aluminum material is relatively weak, and it can be deformed in time after being affected by the stress of the support beam 10 or the support column 11. The stress bar 6 is made of soft steel wire. After the support bar 3 is deformed, the steel wire inside it is pulled, and the steel wire pulls the elastic element 7, and the elastic element 7 is stressed and exerts the stress on the grating 13.

[0044] Specifically, the elastic element 7 is a cantilever beam structure as a whole, the elastic element 7 is made of a metal sheet, and a plurality of vacuum cavities are arranged inside the elastic element 7 .

[0045] Among them, by arranging a vacuum cavity inside the elastic element 7 and using the vacuum cavity layer to achieve heat insulation, the heat conduction of the elastic element 7 itself is greatly reduced, so that the elastic element 7 also achieves the purpose of heat insulation.

[0046] A first mounting hole 14 is formed on one end of the support bar 3 away from the mounting shell 2, and a second mounting hole 15 is formed on the mounting shell 2. The support bar 3 is fixedly mounted on the support beam 10 by using a first bolt 12 to penetrate the first mounting hole 14. The mounting shell 2 is fixedly mounted on the support beam 10 or the support column 11 by using a second bolt 16 to penetrate the second mounting hole 15. The support bar 3 extends the stress acceptance range.

[0047] The above are only preferred specific implementation methods of the utility model, but the protection scope of the utility model is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the utility model, who makes equivalent replacements or changes based on the technical scheme and utility model concept of the utility model, should be covered by the protection scope of the utility model.

Claims

1. A stress monitoring device based on a fiber Bragg grating sensor, which is used to monitor the stress of a support beam (10) or a support column (11) to be monitored, comprising a fiber Bragg grating demodulator and at least one fiber Bragg grating sensor installed on the support beam (10) or the support column (11) to be monitored, wherein the fiber Bragg grating demodulator is communicatively connected to the at least one fiber Bragg grating sensor; Features: The fiber grating sensor comprises an armored optical cable (5), an outer shell (1), an elastic element (7), a mounting shell (2), and two sensing components; one end of the armored optical cable (5) passes through the outer shell (1), and a grating (13) is engraved on the exposed portion of the end of the armored optical cable (5), and one end of the elastic element (7) is fixedly connected to the grating (13); the outer shell (1) is fixedly mounted on a side wall of the mounting shell (2), the mounting shell (2) is in the shape of a disk as a whole, and a sliding groove is provided on the side wall of the mounting shell (2) where the circumference is located; The sensing component comprises a stress bar (6) and a support bar (3) having a certain length. The support bar (3) is slidably connected to the mounting shell (2) via a slide groove. A through groove is provided inside the support bar (3) along the length direction. The stress bar (6) is inserted into the through groove of the support bar (3), and one end of the stress bar (6) is fixedly connected to the inner wall of the end of the support bar (3) away from the mounting shell (2), and the other end of the stress bar (6) is rotatably connected to the elastic element (7); the mounting shell (2) is fixedly mounted on a support beam (10) or a support column (11) for monitoring, and the end of the support bar (3) away from the mounting shell (2) is fixedly mounted on the support beam (10) or the support column (11) for monitoring, and the support bar (3) is in a stretched state.

2. A stress monitoring device based on a fiber grating sensor according to claim 1, characterized in that: The outer portion of the grating (13) is provided with an inner shell (9) covering the grating, one end of the elastic element (7) is located inside the inner shell (9), and the elastic element (7) is fixedly connected to the grating (13) by means of an adhesive.

3. A stress monitoring device based on a fiber grating sensor according to claim 2, characterized in that: A heat insulation layer (8) is provided on the outside of the inner shell (9), and the heat insulation layer (8) is composed of a ceramic silicone rubber layer and an aerogel felt layer.

4. A stress monitoring device based on a fiber grating sensor according to claim 1, characterized in that: A connector (4) is installed on the outer shell (1), and the armored optical cable (5) is fixedly installed on the outer shell (1) via the connector (4).

5. The stress monitoring device based on fiber grating sensor according to claim 1, characterized in that: The support bar (3) is made of aluminum material.

6. A stress monitoring device based on a fiber grating sensor according to claim 1, characterized in that: The elastic element (7) is in the form of a cantilever beam structure as a whole; the elastic element (7) is made of a metal sheet; and a plurality of vacuum cavities are arranged inside the elastic element (7).

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