Multi-degree-of-freedom calibration system and calibration method for nuclear power dome concrete strain sensor installation

Abstract

The present invention discloses a multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor, comprising an installation box, a first dial, a first calibration scale, a third dial, a slide rail, a mounting bracket and a weight. The first dial is arranged on one side of the installation box, the first calibration scale is arranged on the top surface of the installation box and is used in conjunction with the first dial; the weight is suspended at the center of the top surface of the installation box; the third dial with an air bubble is arranged on the top surface of the installation box, and slide rails are arranged on both sides of the third dial, and each slide rail is provided with a mounting bracket that can move along it and is used to install the strain sensor. The calibration system is not affected by space and signals, can ensure that the strain sensor accurately points to the center of the nuclear power containment dome, ensure the accuracy of strain monitoring in the dome area, effectively ensure the data validity of the long-term loss of prestressing in the later nuclear power, provide a reliable database for the later periodic safety review of nuclear power, can be disassembled in real time, and is suitable for relatively narrow areas and large and complex structures in building structures.

Description

Technical Field

[0001] The invention belongs to the technical field of structural monitoring in civil engineering, and in particular relates to a multi-degree-of-freedom calibration system and a calibration method for installing a nuclear power dome concrete strain sensor. Background Art

[0002] In the field of civil engineering, embedded concrete strain gauges are often used to measure the stress and strain of concrete structures. They are widely used in industrial buildings, civil buildings, tunnels, foundation pits, slopes, dams and other engineering fields.

[0003] The containment structure of a nuclear power plant needs to monitor the stress and deformation state of the containment structure during acceptance tests and operation, and evaluate the long-term loss of prestress. The strain measurement points of the containment structure of a nuclear power plant are generally arranged on the bottom plate, tensioning corridor and the joint with the bottom plate, the cylinder area, the dome area and the equipment gate area. The monitoring orientation of the strain measurement points in the dome area of ​​the containment structure of a nuclear power plant is circumferential (tangential), radial, and vertical (or meridional). The radial sensor of the strain measurement point in the dome area needs to point to the center of the dome when installed. However, due to the dense arrangement of steel bars in the nuclear power containment, the complex on-site environment and limited space, the elevation can be located during on-site installation, but the installation angle cannot accurately point to the center. Therefore, according to the actual needs of the site, a multi-degree-of-freedom calibration system for the installation of nuclear power dome concrete strain sensors is invented, so that the strain sensor can accurately point to the center of the nuclear power dome to ensure the accuracy of strain monitoring in the dome area.

[0004] In the prior art, there is a blank in the industry for installing multi-degree-of-freedom calibration devices for strain sensors in the nuclear power field.

[0005] Industrial and civil construction projects use total stations to determine the location of concrete strain sensors, but this method requires a large space and cannot meet the requirements in many narrow structural areas.

[0006] In measurement engineering, in the field of high-precision measurement of small angles, optical methods are widely used for measurement, such as optical dividing head method, polyhedron method, diffraction method, autocollimation method, light method, acousto-optic modulation method, optical internal reflection method, laser interferometry method, ring laser method, etc. However, these methods have a small measurement range, high cost, and relatively complex structure.

[0007] In the photography industry, grating projection three-dimensional shape measurement is calibrated by taking multiple groups of photos of laboratory industrial cameras. The position of the calibration plate can only be simply adjusted by clamping it with a fixture, and it is difficult to clamp the calibration plate stably. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a multi-degree-of-freedom calibration system for the installation of nuclear power dome concrete strain sensors, which solves the problems of instability, large interference, large space occupation and high cost of traditional installation methods, ensures that the strain sensor can accurately point to the center of the nuclear power containment dome, and ensures the accuracy of strain monitoring in the dome area.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0010] According to a first aspect of the present invention, there is provided a multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor, characterized in that the calibration system comprises: an installation box, a first dial, a first calibration scale, a third dial, a slide rail, a mounting bracket and a weight; wherein the first dial is arranged on a side surface of the installation box, the first calibration scale is arranged on the top surface of the installation box and is used in conjunction with the first dial, and the weight is suspended at the center of the top surface of the installation box; the third dial having an air bubble is arranged on the top surface of the installation box, the slide rails are respectively arranged on both sides of the third dial, and each of the slide rails is provided with a mounting bracket that can move along the third dial and is used to install a strain sensor.

[0011] Further, the third scale plate is installed at the center of the top surface of the installation box, and the air bubble is located at the center of the third scale plate.

[0012] Furthermore, the two slide rails are symmetrically arranged on both sides of the third scale plate, and the axes of the two slide rails are parallel to the disk surface of the first scale plate.

[0013] Furthermore, the shape of the upper end portions of the two mounting brackets is adapted to the cross-sectional shape of the mounting shafts at both ends of the strain sensor, and the mounting brackets are detachably connected to the strain sensor.

[0014] Furthermore, the strain sensor is aligned with the air bubble position of the third scale plate.

[0015] Furthermore, the first calibration scale is arranged on the symmetrical center line of the top surface of the installation box and is perpendicular to the surface of the first scale plate, and the first calibration scale coincides with the base point position and the marking line position of the first scale plate.

[0016] Furthermore, the first dial is semicircular.

[0017] Furthermore, the installation box is also provided with a data acquisition module for collecting installation data, an illuminating lamp, and a power supply for supplying power to the data acquisition module and the illuminating lamp.

[0018] Furthermore, the installation box, the first scale plate, the first calibration scale, the third scale plate, the slide rail, the installation bracket, the weight, the data acquisition module and the power supply are integrally formed.

[0019] In a second aspect of the present invention, a method for calibrating the strain sensor installation with multiple degrees of freedom using the calibration system is also disclosed. The calibration method comprises the following steps:

[0020] (1) First, determine the installation position of the strain sensor, and calculate the installation angle θ according to the installation elevation of the measuring point;

[0021] (2) Place the calibration system and the strain sensor at the installation elevation, keep the air bubble position of the third scale plate aligned with the direction of the strain sensor, and ensure that the plane of the third scale plate is perpendicular to the normal section of the dome at this orientation;

[0022] (3) Then aligning the first calibration ruler with the first scale plate base point and the mark line to ensure that the observer's line of sight is on the same horizontal line as the first calibration ruler and the first scale plate;

[0023] (4) Adjust the angle of the installation box, rotate the installation box along the normal section of the dome at this orientation with this elevation as the reference point, and always keep the air bubble position of the third dial in the direction of the strain sensor. When the angle between the weight and the baseline is adjusted to 90°-θ, keep the installation box stationary;

[0024] (5) Fine-tune the position of the strain sensor by means of the slide rail, install the strain sensor on the auxiliary steel bar, wait for the installation to be completed, and then connect and disconnect the mounting bracket from the strain sensor. At this time, the axis of the strain sensor points to the center of the nuclear power containment dome.

[0025] The beneficial technical effects of the present invention are:

[0026] The multi-degree-of-freedom calibration system for installing a concrete strain sensor for a nuclear power dome provided by the present invention is provided with an installation box, on which the strain sensor is arranged, and a dial, a calibration scale and a weight are arranged in the installation box, which not only solves the problems of instability, large interference and large space occupation of the traditional installation method, but also reduces the workload of on-site installation, effectively reduces the on-site labor cost, and can be disassembled and reused in real time, and is suitable for relatively narrow areas and large complex structures in building structures. The calibration method of the present invention can make the concrete strain sensor accurately point to the center of the nuclear power containment dome, and ensure the accuracy of strain monitoring in the dome area. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1It is a schematic diagram of the structure of the calibration system of the present invention;

[0028] Figure 2 This is a simplified diagram for calculating the installation angle of the strain sensor;

[0029] Figure 3 is a schematic diagram of the installation state of the calibration system of the present invention;

[0030] Figure 4 It is a schematic diagram of the adjustment state of the calibration system of the present invention.

[0031] In the figure:

[0032] 1-installation box 2-second scale plate 3-first scale plate 4-slide rail 5-installation bracket 6-third scale plate 7-power switch 8-second calibration scale 9-second calibration scale 10-strain sensor 11-weight O-dome center DETAILED DESCRIPTION

[0033] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0034] like Figure 1 As shown, it is a multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor provided by the present invention, and the calibration system comprises: an installation box 1, a first scale plate 3, a first calibration scale 9, a third scale plate 6, a slide rail 4, a mounting bracket 5 and a weight 11. Among them, the semicircular first scale plate 3 is arranged on a side surface of the installation box 1, the first calibration scale 9 is arranged on the top surface of the installation box 1 and used in conjunction with the first scale plate 3, and the weight 11 is suspended at the center of the top surface of the installation box 1; the third scale plate 6 with air bubbles is arranged on the top surface of the installation box 1, and slide rails 4 are arranged on both sides of the third scale plate 6, and each slide rail 4 is provided with a mounting bracket 5 for mounting a strain sensor 10, and the mounting bracket can move on the slide rail to ensure that the strain sensor has enough moving space.

[0035] The installation box 1 is a frame-shaped structure, and its specifications are determined according to the size of the strain sensor.

[0036] The third scale plate 6 is installed at the center of the top surface of the installation box 1 , and the air bubble on the third scale plate is located at the center of the third scale plate 6 .

[0037] The two slide rails 4 are symmetrically arranged on both sides of the third scale plate 6 , and the axes of the two slide rails 4 are parallel to the surface of the first scale plate 3 .

[0038] The upper end shapes of the two mounting brackets 5 are adapted to the cross-sectional shapes of the mounting shafts at both ends of the strain sensor 10 to support the strain sensor 10 and ensure the reliability of the installation of the strain sensor 10. The relative positions of the two mounting brackets 5 should ensure that the air bubble positions of the strain sensor 10 and the third scale plate 6 are relatively aligned, thereby ensuring the installation angle of the strain sensor. The mounting bracket 5 is preferably made of elastic material to facilitate disassembly and separation from the strain sensor 10.

[0039] The first calibration scale 9 is arranged on the symmetrical center line of the top surface of the installation box 1 and is perpendicular to the disk surface of the first scale plate 3. The first calibration scale 9 coincides with the base point position and the marking line position of the first scale plate 3 to ensure the accuracy of the reading. The base point position is the center position of the first scale plate 3, and the marking line position is the zero degree scale line of the first scale plate 3.

[0040] The installation box 1 is also provided with a data acquisition module for collecting installation data, a lighting lamp, and a power supply for supplying power to the data acquisition module and the lighting lamp. The installation box 1 is provided with a power switch 7, and there are at least two power switches 7, one of which is connected to the lighting lamp to supplement the light source in the installation box to ensure effective reading under dim light; the other is connected to the data acquisition module to ensure that the data can be effectively saved and integrated when data needs to be collected.

[0041] The installation box, first dial, first calibration scale, third dial, slide rail, installation bracket, weight, data acquisition module and power supply of the present invention can be integrally formed before leaving the factory, which can save on-site installation time, effectively reduce on-site labor costs, and reduce the problem of space occupation in concrete.

[0042] In order to facilitate the installation of the installation box at any different angles, the present invention can also install a dial and a corresponding and coordinated approval scale on other sides, such as Figure 1 As shown, for example, a second dial 2 and a second calibration scale 8 can also be set on the other side of the installation box. The installation position and use method of the second dial 2 and the second calibration scale 8 are the same as those of the first dial and the first verification scale, and will not be repeated here.

[0043] The present invention also discloses a method for calibration using the calibration system, comprising the following steps:

[0044] First, determine the installation position of the strain sensor 10, and calculate the installation angle θ according to the installation elevation of the measuring point, such as Figure 2 As shown in the figure The present invention and the strain sensor 10 are placed at the installation elevation, the air bubble position of the third scale plate 6 is aligned with the direction of the strain sensor 10, and the plane of the third scale plate 6 is perpendicular to the normal section of the dome at this position, such as Figure 3As shown. Then, the first calibration ruler 9 is aligned with the base point of the first scale plate 3 and the position of the marking line, ensuring that the observer's line of sight is on the same horizontal line as the first calibration ruler 9 and the first scale plate 3. Adjust the angle, rotate the installation box 1 along the normal section of the dome at this elevation as the base point, and always keep the air bubble position of the third scale plate 6 in the direction of the strain sensor 10 (i.e. aligned). When the angle between the weight 11 and the baseline is adjusted to 90°-θ, keep the installation box 1 still, as shown. Figure 4 The position of the strain sensor 10 is fine-tuned by the slide rail 4, and the strain sensor 10 is installed on the auxiliary steel bar. After the installation is completed, the mounting bracket 5 is connected and separated from the strain sensor 10. At this time, the installation angle of the strain sensor 10 points to the center O of the dome of the nuclear power containment.

[0045] It can be seen that the calibration system provided by the present invention will not be affected by space and signals, ensuring that the strain sensor can accurately point to the center of the nuclear power containment dome, ensuring the accuracy of strain monitoring in the dome area, and effectively ensuring the validity of data on long-term losses of prestressed nuclear power in the later stage, providing a reliable database for the later periodic safety review of nuclear power. Moreover, the calibration system of the present invention can greatly reduce the workload of on-site installation and effectively reduce on-site labor costs; at the same time, the calibration system can be disassembled in real time and can be recycled after disassembly. The calibration system of the present invention can be applied to relatively narrow areas and large and complex structures in building structures.

[0046] The above is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art can make equivalent substitutions or changes based on the technical solutions and inventive concepts disclosed by the present invention, and the obtained technical solutions should be included in the protection scope of the present invention.

Claims

1. A multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor, characterized in that: The calibration system comprises: an installation box (1), a first scale plate (3), a first calibration scale (9), a third scale plate (6), a slide rail (4), a mounting bracket (5) and a weight (11); wherein the first scale plate (3) is arranged on a side surface of the installation box (1), the first calibration scale (9) is arranged on the top surface of the installation box (1) and is used in conjunction with the first scale plate (3), and the weight (11) is suspended at the center of the top surface of the installation box (1); the third scale plate (6) having an air bubble is arranged on the top surface of the installation box (1), the slide rails (4) are respectively arranged on both sides of the third scale plate (6), and each of the slide rails (4) is provided with a mounting bracket that can move along the third scale plate and is used to mount a strain sensor (10).

2. The multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor according to claim 1 is characterized in that: The third scale plate (6) is installed at the center of the top surface of the installation box (1), and the air bubble is located at the center of the third scale plate (6).

3. The multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor according to claim 2 is characterized in that: The two slide rails (4) are symmetrically arranged on both sides of the third scale disk (6), and the axes of the two slide rails (4) are parallel to the disk surface of the first scale disk (3).

4. The multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor according to claim 3 is characterized in that: The shape of the upper ends of the two mounting brackets (5) is adapted to the cross-sectional shape of the mounting shafts at both ends of the strain sensor (10), and the mounting brackets (5) are detachably connected to the strain sensor (10).

5. The multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor according to claim 4 is characterized in that: The strain sensor (10) is aligned with the air bubble position of the third scale plate (6).

6. The multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor according to claim 5, characterized in that: The first calibration scale (9) is arranged on the symmetrical center line of the top surface of the installation box (1) and is perpendicular to the surface of the first scale plate (3); the first calibration scale (9) coincides with the base point position and the marking line position of the first scale plate (3).

7. The multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor according to claim 6, characterized in that: The first scale plate (3) is semicircular.

8. The multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor according to claim 7, characterized in that: The installation box (1) is also provided with a data acquisition module for acquiring installation data, an illuminating lamp, and a power source for supplying power to the data acquisition module and the illuminating lamp.

9. The multi-degree-of-freedom calibration system for installing a nuclear power dome concrete strain sensor according to claim 8, characterized in that: The installation box (1), the first scale plate (3), the first calibration scale (9), the third scale plate (6), the slide rail (4), the installation bracket (5), the weight (11), the data acquisition module and the power supply are integrally formed.

10. A method for calibrating the installation of a strain sensor in multiple degrees of freedom by using the multi-degree-of-freedom calibration system for the installation of a nuclear power dome concrete strain sensor according to any one of claims 1 to 9, comprising the following steps: (1) First, determining the installation position of the strain sensor (10), and calculating the installation angle θ according to the installation elevation of the measuring point; (2) placing the calibration system and the strain sensor (10) at the installation elevation, keeping the air bubble position of the third scale plate (6) aligned with the direction of the strain sensor (10), and ensuring that the plane of the third scale plate (6) is perpendicular to the normal section of the dome at this orientation; (3) Then, the first calibration ruler (9) is aligned with the base point position of the first scale plate (3) and the position of the marking line, so as to ensure that the observer's line of sight is on the same horizontal line as the first calibration ruler (9) and the first scale plate (3); (4) adjusting the angle of the installation box (1), rotating the installation box (1) along the normal section of the dome at this orientation with this elevation as the reference point, and always keeping the air bubble position of the third scale plate (6) in the direction of the strain sensor (10); when the angle between the weight (11) and the baseline is adjusted to 90°-θ, keeping the installation box (1) stationary; (5) The position of the strain sensor (10) is finely adjusted by the slide rail (4), and the strain sensor (10) is installed on the auxiliary steel bar. After the installation is completed, the mounting bracket (5) is connected and disconnected from the strain sensor (10). At this time, the axis of the strain sensor (10) points to the center of the dome of the nuclear power containment vessel.

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