An apparatus and method for measuring the corrosion characteristic parameters of grouting sleeve connectors.

Abstract

This invention discloses an apparatus and method for measuring the corrosion characteristic parameters of grouting sleeve connectors, belonging to the field of prefabricated structures. The apparatus mainly includes a CCD camera and a retractable probe device. The rigid probe of the retractable probe device contacts the surface of the grouting sleeve connector to be tested. The CCD camera is connected to a computer. The relative position of the CCD camera and the retractable probe device remains unchanged during movement. Initially, the rigid probe of the retractable probe device contacts the starting point of the measurement area. When the rigid probe of the retractable probe device moves to the end point of the measurement area, the measurement stops. Throughout the measurement process, the CCD continuously captures video and automatically stores it in the computer. The method is based on the above apparatus to measure the corrosion characteristic parameters of grouting sleeve connectors. This invention can achieve comprehensive and accurate measurement of the size and depth of rust pits, and has application value for evaluating the mechanical property deterioration after corrosion of a large number of widely used prefabricated structures in service.

Description

Technical Field

[0001] This invention relates to the field of prefabricated structures, and in particular to an apparatus and method for measuring the corrosion characteristic parameters of grouting sleeve connectors. Background Technology

[0002] Prefabricated structures have been widely used in buildings and bridges due to their advantages such as fast construction speed and easy quality control. However, prefabricated structures, using reinforced concrete as the main construction material, face the unavoidable risk of corrosion during their service life. As a key force-transmitting component in prefabricated structures, the deterioration of the mechanical properties of grouting sleeve connectors after corrosion directly threatens the structural safety during service.

[0003] The deterioration of the mechanical properties of grouting sleeve connectors is directly related to the characteristic parameters of corrosion on the sleeve surface. Existing studies mostly use visual inspection and weighing methods to obtain the average corrosion degree of the sleeve in grouting sleeve connectors, which is difficult to reflect the deterioration mechanism of the force transmission performance of grouting sleeve connectors caused by the uncertainty of corrosion, and underestimates the potential harm of corrosion to the mechanical properties of prefabricated structures. Existing precision inspection methods mainly include scanning and ultrasonic testing, but these methods are costly, may not be sensitive enough to certain types of corrosion (uniform corrosion), and are unable to test large-volume grouting sleeve connectors due to experimental conditions. Summary of the Invention

[0004] To address the aforementioned technical shortcomings, the purpose of this invention is to provide an apparatus and method for measuring the corrosion characteristic parameters of grouting sleeve connectors, thereby achieving automatic and accurate measurement of the size, depth, and location of corrosion pits on the sleeve surface of grouting sleeve connectors, and solving the defects of high cost and lack of universality in existing detection methods.

[0005] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0006] According to a first aspect of the present invention, an apparatus for measuring corrosion characteristic parameters of a grouting sleeve connector includes: a base, a first driving device, a second driving device, a slide rail, a moving device, a CCD camera, and a retractable probe device. The base is provided with a clamping device for holding the grouting sleeve connector to be tested. The first driving device drives the grouting sleeve connector to be tested to rotate around its own axis. The CCD camera and the retractable probe device are bolted to a cantilever steel plate, and their relative positions remain constant. The CCD camera is connected to a computer and is used to capture video of the entire process of the retractable probe device's extension and contraction. The retractable probe device includes a rigid probe, a probe housing, and a spring. The spring is located inside the probe housing, with its top abutting against the inner top wall of the probe housing. The central axis of the rigid probe and the central axis of the spring are aligned. The top of the rigid probe is fixedly connected to the spring, and the lower part of the rigid probe extends out of the probe housing. During measurement, the rigid probe contacts the surface of the grouting sleeve connector to be measured. The probe housing has a calibrated length used to determine the conversion factor between the CCD camera pixels and the actual vertical movement distance of the rigid probe. The cantilever steel plate can move vertically relative to the moving device and can be fixed at a certain position on the moving device. The moving device slides along the slide rail and is connected to the second drive device, moving along the slide rail under the drive of the second drive device. The slide rail is mounted on the base.

[0007] According to a specific embodiment of the present invention, the clamping device includes a first support, a second support, a first clamping component, and a second clamping component. The first support and the second support are bolted to a base. The first clamping component is detachably mounted on the first support, the second clamping component is detachably mounted on the second support, and the first driving device is mounted on the first support.

[0008] According to a specific embodiment of the present invention, the first clamping component and the second clamping component are spring clamps.

[0009] According to a specific embodiment of the present invention, the first driving device is a stepper motor.

[0010] According to a specific embodiment of the present invention, the moving device includes a steel clamp, a vertical slide rail, a connecting plate, and a base plate. The steel clamp is fastened to the cantilever steel plate by bolts. The steel clamp is disposed on the vertical slide rail and can move along the length of the vertical slide rail and be locked in different positions. The vertical slide rail is fixed to the base plate by the connecting plate, and the connecting plate and the base plate are integrally formed. The connecting plate is connected to the output end of the second driving device. The bottom of the base plate is provided with a sliding groove that matches the slide rail. The second driving device is used to drive the moving device to move along the slide rail.

[0011] According to a specific embodiment of the present invention, the second driving device is a stepper motor.

[0012] According to a specific embodiment of the present invention, the rigid probe is a rigid probe with a ball bearing tip.

[0013] According to a second aspect of the present invention, a method for measuring corrosion characteristic parameters of grouting sleeve connectors, the method being based on the apparatus for measuring corrosion characteristic parameters of grouting sleeve connectors as described in claim 1, specifically comprising:

[0014] Step 1: Immerse the grouting sleeve connector to be tested in a 3.5% dilute hydrochloric acid solution to remove rust and dry it;

[0015] Step 2: Determine the start and end points of the test area on the surface of the grouting sleeve connector to be tested, and mark them accordingly;

[0016] Step 3: Place the grouting sleeve connector to be tested on the device for measuring the corrosion characteristic parameters of the grouting sleeve connector, so that the rigid probe contacts the starting point of the test area, and adjust the lens of the CCD camera to clearly capture the entire rigid probe and the calibration length value on the probe shell.

[0017] Step 4: Adjust the parameters of the first and second drive devices according to the measurement accuracy requirements, determine the rotation speed of the grouting sleeve connector to be measured and the translation distance of each movement of the moving device, and adjust the shooting frame rate of the CCD camera according to the measurement accuracy requirements.

[0018] Step 5: Control the first drive device to rotate the grouting sleeve connector to be tested 360 degrees at the rotation speed described in Step 4. During the rotation of the grouting sleeve connector to be tested, the rigid probe and the surface of the grouting sleeve connector to be tested with different corrosion conditions come into contact, and the spring continuously extends and retracts to reflect the size, depth and position of the corrosion pits on the sleeve surface of the grouting sleeve connector to be tested, so as to obtain the detection data of the grouting sleeve connector to be tested for one revolution. Pause for 2 seconds, and then control the moving device to move through the second drive device, and drive the CCD camera, cantilever steel plate and retractable probe device to move. The translation distance of a single movement is determined by the accuracy required for measurement. After the movement is completed, pause for 2 seconds.

[0019] Step Six: Repeat Step Five continuously. When the rigid probe moves to the end of the measurement area, stop the measurement. Throughout the measurement process, the CCD camera continuously captures video and automatically stores it in the computer.

[0020] Step 7: Decompose the video captured by the CCD camera into images. Using a digital image correlation algorithm, the corresponding pixel in the CCD camera is Y, in pixels. Determine the conversion factor based on the ratio as K = S / Y, where S represents the calibration length on the probe shell in mm. In the actual detection process, the rigid probe extension distance is represented by p pixels in the CCD camera, in pixels. Then, the actual rigid probe movement size L = K*p. The three-dimensional discrete points of the true value of rigid probe extension are obtained by linear interpolation to obtain the distribution characteristic parameters of the location, size, and depth of rust pits on the surface of the rusted sleeve to be tested. Then, the distribution law of rust pits on the sleeve surface can be statistically determined.

[0021] Through the above design scheme, the present invention can bring the following beneficial effects:

[0022] First, the device proposed in this invention can locate and reconstruct rust pits in grouting sleeve connectors with different geometric dimensions and different degrees of corrosion, providing a basis for assessing the degree of corrosion of prefabricated bridges and prefabricated building structures that are widely used.

[0023] Secondly, the core idea of ​​this invention is to transform the acquisition of the corrosion depth of the sleeve surface in the grouting sleeve connector into the high-precision identification of the probe extension amount using digital image correlation algorithm. Combined with a high-precision electric translation stage and a Phytron ESS45 / 2.200.2,5 stepper motor with adjustable speed, the precise positioning of the distribution, size and shape of rust pits can be achieved, thereby automatically and comprehensively acquiring three-dimensional corrosion morphology data of the sleeve surface.

[0024] Third, this invention can compensate for the shortcomings of visual inspection and weighing methods in obtaining the average degree of corrosion of the sleeve, which are difficult to reflect the deterioration mechanism of the force transmission performance of the grouting sleeve connector caused by the uncertainty of corrosion, and underestimate the potential harm of corrosion to the mechanical properties of prefabricated structures.

[0025] Fourth, the measuring device of the present invention has a simple structure, multiple components can be disassembled and assembled, and it is easy to operate. While ensuring the accuracy of the measurement data, the cost of the measuring device is lower than that of 3D laser scanning method and ultrasonic detection method. It also makes up for the shortcomings of these methods, such as not being sensitive enough to certain types of corrosion (uniform corrosion) and being unable to detect large-volume grouting sleeve connectors due to the influence of experimental conditions. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the device for measuring the corrosion characteristic parameters of grouting sleeve connectors proposed in this invention;

[0028] Figure 2 This is a schematic diagram of the mobile device.

[0029] Figure 3 This is a schematic diagram of the retractable probe device;

[0030] The following labels are used in the attached diagram: 1-base; 2-connector of the grouting sleeve to be tested; 3-first support; 4-second support; 5a-first driving device; 5b-second driving device; 6-slide rail; 7-moving device; 7a-steel clamp; 7b-vertical slide rail; 7c-connecting plate; 7d-base plate; 8-CCD camera; 9-cantilever steel plate; 10-retractable probe device; 11-computer; 12-rigid probe; 13-probe housing; 14-spring. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. To avoid obscuring the essence of the present invention, well-known methods, processes, flows, elements, and circuits are not described in detail. It should be understood that the terms "first" and "second" are used for descriptive purposes only, and the features defined by "first" and "second" do not indicate any order, quantity, or importance, but are only used to distinguish different components.

[0032] See Figures 1 to 3The device for measuring the corrosion characteristic parameters of grouting sleeve connectors proposed in this invention includes a base 1, a first driving device 5a, a second driving device 5b, a slide rail 6, a moving device 7, a CCD camera 8, and a retractable probe device 10. The base 1 is equipped with a clamping device for holding the grouting sleeve connector 2 to be tested. The first driving device 5a drives the grouting sleeve connector 2 to rotate around its own axis. The CCD camera 8 and the retractable probe device 10 are fixed to a cantilever steel plate 9 by bolts. The retractable probe device 10 and the CCD camera 8 are connected by the cantilever steel plate... 9 is rigidly connected to the moving device 7. The moving device 7 includes a steel clamp 7a, a vertical slide rail 7b, a connecting plate 7c, and a base plate 7d. In the moving device 7, the vertical slide rail 7b is fixed on the connecting plate 7c. The connecting plate 7c is connected to the output end of the second driving device 5b, and the connecting plate 7c and the base plate 7d are integrally formed. The bottom of the base plate 7d is provided with a sliding groove that matches the slide rail 6. By adjusting the parameters of the second driving device 5b, the distance that the moving device 7 moves along the slide rail 6 in a single movement is adjusted. By controlling the switch of the second driving device 5b, the movement and stop of the moving device 7 are controlled. The cantilever steel plate 9 is bolted to the steel clamp 7a on top of the moving device 7. The steel clamp 7a can move up and down along the vertical slide rail 7b. When it moves to the normal working position of the retractable probe device 10, it is fixed by bolts. The retractable probe device 10 and the CCD camera 8 move synchronously with the moving device 7, and the relative position of the CCD camera 8 and the retractable probe device 10 remains unchanged during the movement. The rigid probe 12 of the retractable probe device 10 contacts the surface of the grouting sleeve connector 2 to be tested. The CCD camera 8 is connected to the computer 11. By controlling the CCD camera 8 to capture the entire process of the retractable probe device 10's expansion and contraction, the depth of the rust pits on the sleeve surface is obtained according to the ratio of pixel coordinates to real coordinates. The second drive device 5b adopts a Phytron ESS45 / 2.200.2,5 stepper motor.

[0033] The clamping device includes a first support 3, a second support 4, a first clamping component, and a second clamping component. The first support 3 and the second support 4 are bolted to the base 1. The first clamping component is detachably mounted on the first support 3, and the second clamping component is detachably mounted on the second support 4. The first driving device 5a is mounted on the first support 3. The relative distance between the first support 3 and the second support 4 can be adjusted according to the size of the grouting sleeve connector 2 being measured. The first clamping component and the second clamping component use spring collets to meet the measurement requirements of grouting sleeve connectors 2 with different diameters. The spring collets are commercially available products and will not be described in detail here. The first driving device 5a is mounted on the first support 3. The first driving device 5a uses a Phytron ESS45 / 2.200.2,5 stepper motor, and its rotation angle during the measurement process can be adjusted according to the specific accuracy requirements. By matching the speed of the Phytron ESS45 / 2.200.2,5 stepper motor and the movement distance of the moving device 7 for each movement, it is possible to achieve comprehensive and accurate measurement of the location of rust pits and the three-dimensional geometric dimensions of the surface of the grouting sleeve connector 2 to be tested.

[0034] The rigid probe 12 is a rigid probe with a ball bearing tip, which ensures that the rigid probe 12 moves smoothly on the sleeve surface.

[0035] This invention also proposes a method for measuring the corrosion characteristic parameters of grouting sleeve connectors, including:

[0036] Step 1: Immerse the grouting sleeve connector 2 to be tested in a 3.5% dilute hydrochloric acid solution to remove rust and dry it;

[0037] Step 2: Determine the start and end points of the test area on the surface of the grouting sleeve connector 2, and mark them accordingly;

[0038] Step 3: Fix the grouting sleeve connector 2 to be tested onto the base 1 using the clamping device. Fix the CCD camera 8 and the retractable probe device 10 to the cantilever steel plate 9 using bolts. The retractable probe device 10 and the CCD camera 8 are rigidly connected to the cantilever steel plate 9 and the moving device 7, moving synchronously with the moving device 7. During the movement, the relative positions of the CCD camera 8 and the retractable probe device 10 remain unchanged. When the retractable probe device 10 is moved to a position where it can operate normally, it can be fixed with bolts. Make the rigid probe 12 contact the starting point of the test area. At this time, the spring 14 in the retractable probe device 10 is in its normal extended state. Adjust the lens of the CCD camera 8 to clearly capture the entire rigid probe 12 and the calibrated length on the retractable probe device 10.

[0039] Step 4: Adjust the parameters of the first drive device 5a and the second drive device 5b according to the measurement accuracy requirements, and determine the rotation speed of the grouting sleeve connector 2 to be measured and the translation distance of the moving device 7 for each step; adjust the shooting frame rate of the CCD camera 8 according to the measurement accuracy requirements.

[0040] Step 5: Control the first drive device 5a to rotate the grouting sleeve connector 2 to be tested 360 degrees at the rotation speed described in Step 4. During the rotation of the grouting sleeve connector 2 to be tested, the rigid probe 12 and the surfaces of the grouting sleeve connector 2 with different corrosion conditions come into contact, and the spring 14 continuously extends and retracts to reflect the size, depth and position of the corrosion pits on the sleeve surface of the grouting sleeve connector 2 to be tested, so as to obtain the detection data of the grouting sleeve connector 2 for one revolution. Pause for 2 seconds, and then control the moving device 7 to move through the second drive device 5b, and drive the CCD camera 8, the cantilever steel plate 9 and the retractable probe device 10 to move. The translation distance of a single movement is determined by the accuracy required for measurement. After the movement is completed, pause for 2 seconds.

[0041] Step 6: Repeat step 5 continuously. When the rigid probe 12 of the retractable probe device 10 moves to the end of the measurement area, stop the measurement. During the entire measurement process, the CCD camera 8 continuously captures video and automatically stores it in the computer 11.

[0042] Step 7: Decompose the video captured by CCD camera 8 into images. Use a digital image correlation algorithm. The probe shell 13 has a calibrated length in mm with an accuracy of 0.001 mm. The corresponding pixel in CCD camera 8 is Y in pixels. Determine the conversion factor K based on the ratio, K = S / Y, where S is the calibrated length. In the actual detection process, the probe extension distance is represented by p pixels in CCD camera 8. The actual probe movement size L = K * p. Use linear interpolation to obtain the three-dimensional discrete points of the probe extension true value to obtain the distribution characteristics of the location, size, and depth of rust pits on the surface of the rusted sleeve. Then, the distribution pattern of rust pits on the sleeve surface can be statistically determined.

[0043] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A device for measuring the corrosion characteristic parameters of grouting sleeve connectors, characterized in that, include: The system comprises a base (1), a first drive device (5a), a second drive device (5b), a slide rail (6), a moving device (7), a CCD camera (8), and a retractable probe device (10). The base (1) is equipped with a clamping device for holding the grouting sleeve connector (2) to be tested. The first drive device (5a) drives the grouting sleeve connector (2) to rotate around its own axis. The CCD camera (8) and the retractable probe device (10) are bolted to a cantilever steel plate (9), and their relative positions remain constant. The CCD camera (8) is connected to a computer (11) and is used to capture video of the entire process of the retractable probe device (10)'s extension and contraction. The retractable probe device (10) includes a rigid probe (12), a probe housing (13), and a spring (14). The spring (14) is located inside the probe housing (13), and... The top of the spring (14) abuts against the inner top wall of the probe housing (13); the central axis of the rigid probe (12) and the central axis of the spring (14) are on a straight line, the top of the rigid probe (12) is fixedly connected to the spring (14), and the lower part of the rigid probe (12) extends out of the probe housing (13). During measurement, the rigid probe (12) contacts the surface of the grouting sleeve connector (2) to be measured; the probe housing (13) has a calibrated length, which is used to determine the conversion coefficient between the CCD camera (8) pixel and the actual vertical movement distance of the rigid probe (12); the cantilever steel plate (9) can move vertically relative to the moving device (7) and can be fixed at a certain position of the moving device (7); the moving device (7) is slidably engaged with the slide rail (6), and the moving device (7) is connected to the second driving device (5b), and moves along the slide rail (6) under the drive of the second driving device (5b); the slide rail (6) is mounted on the base (1).

2. The device for measuring the corrosion characteristic parameters of grouting sleeve connectors according to claim 1, characterized in that, The clamping device includes a first support (3), a second support (4), a first clamping component and a second clamping component. The first support (3) and the second support (4) are bolted to the base (1). The first clamping component is detachably mounted on the first support (3), and the second clamping component is detachably mounted on the second support (4). The first driving device (5a) is mounted on the first support (3).

3. The device for measuring the corrosion characteristic parameters of grouting sleeve connectors according to claim 2, characterized in that, The first clamping component and the second clamping component are spring collets.

4. The device for measuring the corrosion characteristic parameters of grouting sleeve connectors according to claim 2, characterized in that, The first driving device (5a) is a stepper motor.

5. The device for measuring the corrosion characteristic parameters of grouting sleeve connectors according to claim 1, characterized in that, The moving device (7) includes a steel clamp (7a), a vertical slide rail (7b), a connecting plate (7c), and a base plate (7d). The steel clamp (7a) is fastened to the cantilever steel plate (9) by bolts. The steel clamp (7a) is set on the vertical slide rail (7b) and can move along the length of the vertical slide rail (7b) and be locked in different positions. The vertical slide rail (7b) is fixed to the base plate (7d) by the connecting plate (7c), and the connecting plate (7c) and the base plate (7d) are integrally formed. The connecting plate (7c) is connected to the output end of the second driving device (5b). The bottom of the base plate (7d) is provided with a sliding groove that matches the slide rail (6). The second driving device (5b) is used to drive the moving device (7) to move along the slide rail (6).

6. The apparatus for measuring the corrosion characteristic parameters of grouting sleeve connectors according to claim 5, characterized in that, The second drive device (5b) is a stepper motor.

7. The device for measuring the corrosion characteristic parameters of grouting sleeve connectors according to claim 1, characterized in that, The rigid probe (12) is a rigid probe with a ball bearing tip.

8. A method for measuring the corrosion characteristic parameters of grouting sleeve connectors, characterized in that, This method, based on the apparatus for measuring the corrosion characteristic parameters of grouting sleeve connectors as described in claim 1, specifically includes: Step 1: Soak the grouting sleeve connector (2) to be tested in a 3.5% dilute hydrochloric acid solution to remove rust and dry it; Step 2: Determine the start and end points of the test area on the surface of the grouting sleeve connector (2) and mark them; Step 3: Place the grouting sleeve connector (2) to be tested on the device for measuring the corrosion characteristic parameters of the grouting sleeve connector, so that the rigid probe (12) contacts the starting point of the test area, and adjust the lens of the CCD camera (8) to clearly capture the calibration length value on the entire rigid probe (12) and the probe shell (13). Step 4: According to the measurement accuracy requirements, adjust the parameters of the first drive device (5a) and the second drive device (5b), determine the rotation speed of the grouting sleeve connector (2) to be measured and the translation distance of the moving device (7) for each step, and adjust the shooting frame rate of the CCD camera (8) according to the measurement accuracy requirements. Step 5: Control the first drive device (5a) to rotate the grouting sleeve connector (2) to be tested by 360 degrees at the rotation speed described in Step 4. During the rotation of the grouting sleeve connector (2), the rigid probe (12) and the surfaces of the grouting sleeve connector (2) under different corrosion conditions come into contact, and the spring (14) continuously extends and retracts to reflect the size, depth and position of the corrosion pits on the sleeve surface of the grouting sleeve connector (2) to be tested, so as to obtain the detection data of the grouting sleeve connector (2) to be tested for one week. Pause for 2 seconds, and then control the moving device (7) to move through the second drive device (5b), and drive the CCD camera (8), cantilever steel plate (9) and retractable probe device (10) to move. The translation distance of a single movement is determined by the accuracy required for measurement. After the movement is completed, pause for 2 seconds. Step 6: Repeat step 5 continuously. When the rigid probe (12) moves to the end of the measurement area, stop the measurement. During the entire measurement process, the CCD camera (8) continuously captures video and automatically stores it in the computer (11). Step 7: Decompose the video captured by the CCD camera (8) into images. Use the digital image correlation algorithm. The corresponding pixel in the CCD camera (8) is Y, in pixels. Determine the conversion factor K = S / Y based on the ratio, where S represents the calibration length on the probe shell in mm. In the actual detection process, the extension distance of the rigid probe (12) is represented by p in pixels in the CCD camera (8), in pixels. Then the actual rigid probe (12) movement size L = K*p. The three-dimensional discrete points of the true extension value of the rigid probe (12) are obtained by linear interpolation. The distribution characteristic parameters of the location, size and depth of the rust pits on the surface of the rusted sleeve to be tested are obtained. Then the distribution law of the rust pits on the sleeve surface can be statistically determined.

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