Loading experiment device and loading experiment method for quick joint

Abstract

The invention belongs to the related technical field of tunnel engineering, and discloses a loading experiment device and a loading experiment method.The fast-splicing joint comprises a female clamping joint and a male clamping joint, and the loading experiment device comprises a mechanical property monitoring mechanism, the mechanical property monitoring mechanism comprises a first strain sensor arranged on the wall face of the female clamping connector and a second strain sensor arranged on the side face of the male clamping connector. The first strain sensor is used for acquiring deformation information of the female clamping connector during a loading experiment, the second strain sensor is used for acquiring deformation information of the male clamping connector during the loading experiment, and then the mechanical property of the quick-splicing connector is analyzed and acquired according to the deformation information. The first strain sensor and the second strain sensor are arranged, so that the quick joint has a mechanical measurement function, deformation information of the quick joint can be monitored and obtained in the loading experiment process, and then the stress mechanical property of the joint under the load can be obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field related to tunnel engineering, and more specifically, relates to a loading test device and a loading test method for a quick-splicing joint. Background Art

[0002] In recent years, with the increasing severity of urban traffic congestion, more and more cities have begun to build subway projects. Shield machines have dominated the construction of urban subway projects because of their low environmental impact, suitability for deep burial, high earth pressure, high water pressure construction, low cost, and wide application range. They have become an indispensable general tunnel construction technology.

[0003] In the past three decades, shield technology has developed rapidly and shield forms have become diversified. Shield tunnel segments are an important part of shield mechanisms, but the mechanical properties of segment joints are often overlooked. When the structure is deformed, the load carried by the joint will change first, and under the influence of complex external environmental forces and thermal factors, the change law of bolt load is extremely complex. In addition, there are special measurement requirements for joint loads in special occasions, such as measuring the axial force and shear force of segment joints under instantaneous high load conditions, or analyzing and predicting the long-term operation of segments by long-term monitoring of joint preload changes; as well as the stress conditions of joints in special circumstances, such as fire. In traditional shield professions, joints exist only as structural parts and do not have mechanical measurement functions. There is a lack of detection and acquisition methods for the mechanical properties of segment joints under load. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a loading test device and a loading test method for quick-splicing joints, which solves the problem that the existing shield segment joints only exist as structural parts, do not have mechanical measurement functions, and lack detection and acquisition means for the stress performance of the segment joints under load. By setting up a mechanical performance monitoring mechanism, the mechanical properties of the quick-splicing joint can be analyzed and obtained in the loading experiment.

[0005] To achieve the above-mentioned object, according to one aspect of the present invention, a loading test device for a quick-joint is provided, wherein the quick-joint comprises a female card joint and a male card joint, wherein the male card joint is inserted into the open end of the female card joint to realize the connection between the two, and wherein the loading test device comprises a mechanical property monitoring mechanism, wherein the mechanical property monitoring mechanism comprises a first strain sensor disposed on the wall surface of the female card joint and a second strain sensor disposed on the side surface of the male card joint;

[0006] The first strain sensor is used to obtain the deformation information of the female card joint when the quick-joint is subjected to a loading test, and the second strain sensor is used to obtain the deformation information of the male card joint when the quick-joint is subjected to a loading test, and then the mechanical properties of the quick-joint are obtained based on the deformation information of the female card joint and the deformation information of the male card joint.

[0007] According to the loading test device for quick-joints provided by the present invention, the female card joint includes two opposite wall surfaces, and the first strain sensors are respectively fixedly provided on the inner sides of the two opposite wall surfaces; the second strain sensor is arranged on the male card joint along the insertion direction of the male card joint, and the second strain sensors are respectively provided on the two opposite side surfaces of the male card joint.

[0008] According to the loading test device for quick-joints provided by the present invention, the first strain sensor is spaced apart from the opening end of the female connector, so as to be spaced apart from the insertion end of the male connector.

[0009] According to the loading test device for quick-joints provided by the present invention, a groove is provided on the side of the male connector, and the second strain sensor package is arranged inside the groove.

[0010] According to the loading test device for quick-joints provided by the present invention, the mechanical property monitoring mechanism also includes a camera arranged on one side of the quick-joint, and the camera is used to capture images of the plug-in connection surfaces of the female card connector and the male card connector when the loading test is performed on the quick-joint, so as to obtain the extrusion deformation condition of the plug-in connection between the female card connector and the male card connector through image analysis.

[0011] According to another aspect of the present invention, a loading test method for a quick-joint is provided. Based on any of the above-mentioned loading test devices for quick-joints, the loading test method comprises performing a step-by-step loading test on the quick-joint. The step-by-step loading test on the quick-joint specifically comprises:

[0012] Determining the loading conditions for the step-by-step loading test of the quick-joint;

[0013] Arrange the load direction and the loading position according to the determined loading condition, and perform a step-by-step loading experiment in a step-by-step loading manner to obtain monitoring data of the mechanical property monitoring mechanism in each step of the loading experiment, wherein the step-by-step loading manner is a loading manner in which the load is gradually increased;

[0014] The stress performance of the quick-joint under step-by-step loading conditions is obtained based on the monitoring data analysis of the mechanical property monitoring mechanism.

[0015] According to the loading test method for quick-joints provided by the present invention, before the step-by-step loading test is performed in a step-by-step manner, the method further comprises:

[0016] The load loading direction and loading position are arranged according to the determined loading condition, and a preloading experiment is carried out. The preloading experiment is achieved by applying a preset load, wherein the preset load is 40%-60% of the maximum bearing capacity of the quick-joint under the determined loading condition.

[0017] According to the loading test method for a quick-joint provided by the present invention, the loading conditions for the quick-joint to undergo a step-by-step loading test include:

[0018] Axial bending condition: applying a uniformly distributed load to the quick-joint as a whole, measuring the overall bending moment and the deformation of the quick-joint;

[0019] Axial shear condition: applying a uniformly distributed load to the female clamp joint or the working clamp joint area, and measuring the shear force change;

[0020] In the axial tensile condition, an axial reverse force is applied to the female card joint and the working card joint to measure the tensile deformation.

[0021] According to the loading test method for a quick-joint provided by the present invention, after the quick-joint is subjected to a step-by-step loading test, the method further comprises:

[0022] A loading experiment simulating actual working conditions is performed on the quick-joint, and the stress performance of the quick-joint under the simulation of actual working conditions is obtained based on the monitoring data of the mechanical property monitoring mechanism obtained in the experiment.

[0023] According to the loading test method for the quick-joint provided by the present invention, the mechanical property monitoring mechanism further includes a camera, which is used to take images of the plug-in connection surfaces of the female card connector and the male card connector when the quick-joint is subjected to the loading test, so as to obtain the extrusion deformation of the plug-in connection between the female card connector and the male card connector through image analysis, and the loading test method further includes:

[0024] Spray polymer microspheres on the surface of the quick-joint joint to evenly cover the opening end of the female connector and the insertion end of the male connector on the camera shooting surface, so that the camera can capture the displacement changes of the polymer microspheres;

[0025] During the loading experiment, the shooting surface of the camera is illuminated by a laser, and the movement trajectory of the polymer microspheres during the experiment is recorded by the camera. The extrusion deformation of the male card connector and the female card connector during the loading experiment is obtained by analyzing the movement trajectory of the polymer microspheres during the experiment.

[0026] In general, compared with the prior art, the above technical solutions conceived by the present invention provide a loading test device and a loading test method for a quick-joint joint:

[0027] 1. By setting the first strain sensor and the second strain sensor, the quick-joint joint has a mechanical measurement function, which can monitor and obtain the deformation information of the quick-joint joint during the loading test, and thus can realize the acquisition of the mechanical properties of the joint under load;

[0028] 2. Furthermore, the specific arrangement of the first strain sensor and the second strain sensor will not affect the normal use of the male and female joints, and can obtain strain information of the joints at multiple locations, so as to be able to analyze the stress performance of the joints more comprehensively and accurately;

[0029] 3. The loading test conditions of the quick-joint are divided into loading conditions for step-by-step loading tests and loading conditions for actual working condition simulation loading tests. This can not only obtain the mechanical properties of the quick-joint in a comprehensive and systematic manner, but also obtain the mechanical properties that the quick-joint needs to know in actual applications in a targeted manner, which is highly practical.

[0030] 4. Furthermore, the specific setting of the loading test is also conducive to ensuring the safe and stable progress of the loading experiment. At the same time, during the loading process, it is conducive to protecting the structural system and preventing overload and damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a side schematic diagram of the mechanical property monitoring mechanism provided by the present invention being arranged on a quick-splicing joint;

[0032] Figure 2 It is a schematic diagram of the setting of the camera provided by the present invention;

[0033] Figure 3 It is a load schematic diagram of the shaft bending working condition loading experiment provided by the present invention;

[0034] Figure 4 It is a load schematic diagram of the axial tensile working condition loading experiment provided by the present invention;

[0035] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0036] 1-female card connector; 2-male card connector; 3-first strain sensor; 4-second strain sensor; 5-camera; 6-first connecting piece; 7-second connecting piece. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] See also Figure 1 The present invention provides a loading test device for a quick-joint, wherein the quick-joint comprises a female card joint 1 and a male card joint 2, wherein the male card joint 2 is inserted into the open end of the female card joint 1 to realize the connection between the two, and the loading test device comprises a mechanical property monitoring mechanism, wherein the mechanical property monitoring mechanism comprises a first strain sensor 3 provided on the wall surface of the female card joint 1 and a second strain sensor 4 provided on the side surface of the male card joint 2;

[0039] The first strain sensor 3 is used to obtain the deformation information of the female card joint 1 when the quick-joint is subjected to a loading test, and the second strain sensor 4 is used to obtain the deformation information of the male card joint 2 when the quick-joint is subjected to a loading test, and then the mechanical properties of the quick-joint are obtained based on the deformation information of the female card joint 1 and the deformation information of the male card joint 2.

[0040] In this embodiment, the female card connector 1 and the male card connector 2 are connected by plugging to achieve a quick-joint connection. In order to detect and obtain the mechanical properties of the quick-joint, this embodiment proposes that a loading test device can be set up to perform a loading test on the quick-joint, so as to obtain the mechanical properties of the quick-joint under stress through the experiment, so as to guide the quick-joint in practical applications. The specific loading test device is provided with a mechanical property monitoring mechanism, which is used to monitor and obtain the deformation information of the quick-joint during the loading test, and then the mechanical properties of the quick-joint can be obtained according to the deformation information.

[0041] Specifically, a first strain sensor 3 is provided on the female card connector 1, and the first strain sensor 3 can detect and obtain the strain deformation occurring on the surface of the female card connector 1 during the loading test, and can analyze the mechanical properties of the quick-joint joint by judging whether the deformation of the female card connector 1 is within a preset range, etc. according to the strain deformation. Similarly, a second strain sensor 4 is provided on the male card connector 2, and the second strain sensor 4 can detect and obtain the strain deformation occurring on the surface of the male card connector 2 during the loading test, and then analyze the mechanical properties of the quick-joint joint according to the strain deformation. By providing the first strain sensor 3 and the second strain sensor 4, the quick-joint joint has a mechanical measurement function, and can monitor and obtain the deformation information of the quick-joint joint during the loading test, and then can realize the acquisition of the mechanical properties of the joint under load.

[0042] In some specific embodiments, the quick-joint joint is an I-type standard block combined mortise and tenon joint, the male card joint 2 includes an I-type component, and the female card joint 1 includes a C-type component. In other embodiments, the quick-joint joint may also be other joint forms that can achieve quick-joint connection, for example, the female card joint 1 may have a slot, and the male card joint 2 may have a plug, and the two are connected through the slot and the plug to achieve quick-joint connection, etc. The specific form of the joint is not limited.

[0043] The quick-joint joint can be a joint for connecting shield segments. By performing a loading test on the quick-joint joint, the mechanical properties of the joint can be obtained, thereby providing guidance for the specific setting and use of the segment joint in practical applications. The quick-joint joint can also be used in other fields, without specific limitation.

[0044] In some specific embodiments, reference Figure 1 The female card connector 1 includes two opposite walls, and the first strain sensors 3 are fixedly arranged on the inner sides of the two opposite walls; the second strain sensor 4 is arranged on the male card connector 2 along the insertion direction of the male card connector 2, and the second strain sensors 4 are arranged on the two opposite sides of the male card connector 2. That is, the second strain sensor 4 on the male card connector 2 can be arranged Figure 1 On the side of the male card connector 2 shown, it can also be on the side opposite to the side ( Figure 1 (not shown) A second strain sensor 4 is also provided so that strain information of the male card connector 2 can be obtained at multiple locations, so as to be able to analyze the stress performance of the connector more comprehensively and accurately.

[0045] In some specific embodiments, the first strain sensor 3 is spaced apart from the open end of the female connector 1, so as to be spaced apart from the insertion end of the male connector 2. This is to prevent the male connector 2 from compressing and affecting the first strain sensor 3 when plugged into the female connector 1, thereby affecting the normal use of the first strain sensor 3. That is, the arrangement of the sensor does not affect the normal use of the male and female connectors, and the connection of the male and female connectors does not affect the normal use of the sensor.

[0046] In some specific embodiments, a groove is provided on the side of the male card connector 2, and the second strain sensor 4 is packaged inside the groove.

[0047] Specifically, the first strain sensor 3 includes an LVDT sensor; the second strain sensor 4 includes an FBG fiber grating sensor. Two LVDT sensors are located on the upper and lower inner walls of the mother card connector 1, one each; they are installed close to the inner wall, for example, the model GT50-10MM-V1 can be used. The LVDT sensor has high resolution and good sensitivity. For example, an LVDT sensor with a resolution of less than 0.1μm can be selected. The LVDT sensor has high measurement accuracy and good repeatability. For example, an LVDT sensor with a linear accuracy of 0.25% can be selected. The LVDT sensor has good anti-interference performance and low output impedance, and is suitable for more complex field environments.

[0048] The FBG fiber grating sensor uses a surface-welded fiber optic strain sensor or a surface-bonded fiber optic strain sensor (for example, model CS-S-FBG-MS-01 / 02), which can adapt to different surfaces of components. Two FBG fiber grating sensors are located on the side surface of the male connector 2; a groove slightly wider than the width of the fiber optic sensor is engraved on the side of the male connector 2, and the fiber optic grating sensor is encapsulated with epoxy resin to measure the strain information of the male connector 2 in real time, and then analyze the force information of the male connector 2. For example, the axial force information of the male connector 2 can be obtained based on the strain-stress relationship analysis known in advance. The axial direction is the insertion direction of the male connector 2, that is, Figure 1 The setting extension direction of the second strain sensor 4 is shown in FIG.

[0049] Fiber Bragg grating sensor adopts optical fiber signal transmission, and has strong anti-electromagnetic interference ability; at the same time, it has good electrical insulation performance, corrosion resistance and high temperature resistance; the strain measurement range is ±1500με; the measurement accuracy is high, the sensitivity is high, and the accuracy can reach 0.1um; the operating temperature range is -40~80℃. The specific structure of FBG fiber Bragg grating sensor includes: prefabricated fiber joint + 1.0mm stainless steel seamless steel pipe + single-point fiber Bragg grating (in the middle) + tail end seal / prefabricated fiber joint. That is, the FBG fiber Bragg grating sensor can be provided with a prefabricated fiber joint at the front end, and a tail end seal / prefabricated fiber joint at the rear end. The front and rear end joints are connected by a single-point fiber Bragg grating, and in order to protect the single-point fiber Bragg grating, a steel pipe can be set on its outer side to avoid damage to the single-point fiber Bragg grating and affect the measurement, thereby improving reliability.

[0050] Further, refer to Figure 2 The mechanical property monitoring mechanism also includes a camera 5 arranged on one side of the quick-joint, and the camera 5 is used to take images of the plug-in connection surfaces of the female card connector 1 and the male card connector 2 when the quick-joint is subjected to a loading test, so as to obtain the extrusion deformation of the plug-in connection between the female card connector 1 and the male card connector 2 through image analysis.

[0051] The mechanical property monitoring mechanism also includes a light source that cooperates with the camera 5. The light source uses a broadband tunable laser to change the laser output wavelength within a certain range. Here, a wavelength of 532nm is selected. The camera 5 can be a high-speed camera 5, and CCD or CMOS imaging can be used. Its optical imaging system adds an infrared cutoff filter (IR-cut filter, IRCF) to eliminate interference. IRCF adopts an absorption type, and the surface is coated with blue glass. The copper ions in the blue glass have a strong absorption effect on infrared light, and the imaging effect is good.

[0052] Specifically, when the camera 5 captures an image of the plug-in connection surface of the female card connector 1 and the male card connector 2, polymer microspheres can be sprayed on the surface of the open end of the female card connector 1 and the insertion end of the male card connector 2. The polymer microspheres should at least cover the open end of the female card connector 1 and the insertion end of the male card connector 2 on the camera 5 shooting surface, so that the extrusion deformation of the plug-in connection of the female card connector 1 and the male card connector 2 can be analyzed by analyzing the displacement change of the polymer microspheres in the captured image. The image captured by the camera 5 can be processed by PIV lab, and the image data can be processed by CLAHE preprocessor. PIV lab and CLAHE preprocessor are existing image processing methods, and the details will not be repeated.

[0053] The camera 5 can capture the side of the cross section where the female card connector 1 and the male card connector 2 are connected, that is, Figure 1 The side shown; the polymer microspheres should be arranged at least on this side, and on this side at least at the open end of the female card connector 1 and the insertion end of the male card connector 2, that is, at least at the contact point of the female card connector 1 and the male card connector 2 on the shooting surface, so that the extrusion deformation of the plug-in connection between the female card connector 1 and the male card connector 2 can be reflected by the displacement change of the polymer microspheres.

[0054] Furthermore, the loading test device for the quick-joint also includes a loading mechanism, which is used to apply a load to the quick-joint in the loading test. For example, a multi-channel loading mechanism can be used to achieve loading in multiple different directions. The loading mechanism can be a hydraulic loading mechanism such as a hydraulic cylinder, which converts electrical signals into hydraulic signals through an electro-hydraulic servo controller to accurately control the position, speed and strength of the loading mechanism. The loading mechanism system can also monitor the execution status, such as setting a mechanical sensor on the loading contact surface, and controlling the electro-hydraulic servo controller through a feedback loop to maintain the stability and accuracy of the loading mechanism.

[0055] The loading mechanism should be able to load loads in multiple directions. This can be achieved by setting up multiple loading mechanisms in different directions, or by setting up a mechanical arm to connect the loading mechanism to achieve changes in the direction of the loading load, which is used to simulate the impact force during actual assembly, and is also convenient for simulating the force and displacement under other working conditions. The loading mechanism should be able to meet the required loading force to simulate the required working conditions; by simulating different working conditions, it can meet the requirements of analyzing and measuring the deformation of the joint under different working conditions.

[0056] Furthermore, the present invention also provides a loading test method for a quick-joint, which is based on the loading test device for a quick-joint described in any one of the above items, and the loading test method includes performing a step-by-step loading test on the quick-joint, and the step-by-step loading test on the quick-joint specifically includes:

[0057] Determining the loading conditions for the step-by-step loading test of the quick-joint;

[0058] Arrange the load direction and the loading position according to the determined loading condition, and perform a step-by-step loading experiment in a step-by-step loading manner to obtain monitoring data of the mechanical property monitoring mechanism in each step of the loading experiment, wherein the step-by-step loading manner is a loading manner in which the load is gradually increased;

[0059] The stress performance of the quick-joint under step-by-step loading conditions is obtained based on the monitoring data analysis of the mechanical property monitoring mechanism.

[0060] Furthermore, before the step-by-step loading experiment is performed in a step-by-step loading manner, the following steps are also included:

[0061] The load loading direction and loading position are arranged according to the determined loading condition, and a preloading experiment is carried out. The preloading experiment is achieved by applying a preset load, wherein the preset load is 40%-60% of the maximum bearing capacity of the quick-joint under the determined loading condition.

[0062] Specifically, the loading conditions of the step-by-step loading test of the quick-joint include:

[0063] Axial bending condition: applying a uniformly distributed load to the quick-joint as a whole, measuring the overall bending moment and the deformation of the quick-joint;

[0064] Axial shear condition: a uniformly distributed load is applied to the female clamp joint 1 or the work clamp joint area, and the shear force change is measured;

[0065] In the axial tensile condition, an axial force in the opposite direction is applied to the female clamp joint 1 and the working clamp joint, and the tensile deformation is measured.

[0066] Furthermore, after the quick-joint is subjected to a step-by-step loading test, the method further comprises:

[0067] A loading experiment simulating actual working conditions is performed on the quick-joint, and the stress performance of the quick-joint under the simulation of actual working conditions is obtained based on the monitoring data of the mechanical property monitoring mechanism obtained in the experiment.

[0068] The loading conditions of the quick-joint loading experiment for simulating actual working conditions include instantaneous load conditions, long-term load conditions or special scenario conditions.

[0069] The loading test conditions of the quick-joint are divided into loading conditions for step-by-step loading tests and loading conditions for actual working condition simulation loading tests; the loading conditions for step-by-step loading tests are conditions related to the overall system mechanical performance measurement of the quick-joint. Through different step-by-step loading test loading conditions, the mechanical properties of the quick-joint in different directions can be systematically obtained, and the mechanical properties of the quick-joint can be measured and obtained as a whole. The loading conditions for the actual working condition simulation loading test are more targeted at some conditions where the mechanical properties of the quick-joint need to be known in actual applications.

[0070] Therefore, this embodiment proposes that a step-by-step loading test can be performed on the quick-joint first, and after the overall mechanical properties of the quick-joint are known, a loading test simulating actual working conditions can be performed to specifically obtain the mechanical properties of the quick-joint under some actual simulated working conditions, which is beneficial to ensuring the safe and stable progress of the loading experiment. At the same time, during the loading process, it is beneficial to protect the structural system and prevent overload and damage.

[0071] Furthermore, the mechanical property monitoring mechanism further includes a camera 5, which is used to capture images of the plug-in connection surfaces of the female card connector 1 and the male card connector 2 when the quick-joint joint is subjected to a loading test, so as to obtain the extrusion deformation of the plug-in connection between the female card connector 1 and the male card connector 2 through image analysis. The loading test method further includes:

[0072] Spray polymer microspheres on the surface of the quick-joint joint to evenly cover the opening end of the female connector 1 and the insertion end of the male connector 2 on the shooting surface of the camera 5, so that the camera 5 can capture the displacement change of the polymer microspheres;

[0073] During the loading experiment, the shooting surface of the camera 5 is illuminated by laser, and the movement trajectory of the polymer microspheres during the experiment is recorded by the camera 5. The extrusion deformation of the male card connector 2 and the female card connector 1 during the loading experiment is obtained by analyzing the movement trajectory of the polymer microspheres during the experiment.

[0074] Furthermore, the present invention provides a loading test device and a loading test method for a new type of quick-joint intelligent joint, the purpose of which is to effectively measure and monitor the changes in joints in splicing occasions and some special occasions, and to analyze and predict the long-term operation of the segments by long-term monitoring of the changes in the joint preload; it is used to solve the problem of the lack of mechanical properties under load changes in traditional shield segment joints, and to provide a loading test device for an intelligent sensing joint that can provide real-time feedback on the joint stress.

[0075] Among them, the loading experimental device includes an I-type standard block combined mortise and tenon joint, specifically including a female card joint 1 and a male card joint 2 spliced ​​to each other, and an elastic deformation cavity is formed between the female card joint 1 and the male card joint 2; two FBG fiber grating sensors are encapsulated on the side surface of the male card joint 2, and grooves can be symmetrically engraved on both sides of the I-type component, and optical fiber lines are led out from the bottom of the male card joint 2; two LVDT sensors are located on the inner wall of the female card joint 1, which are used to measure the strain change during assembly; a high-speed camera 5 is located on the right side of the mortise and tenon joint as a measuring device, placed along the cross-section of the male and female joints of the mortise and tenon joint, and the extrusion and deformation of the male and female joints during loading are analyzed and measured through image processing; a loading mechanism with an electro-hydraulic servo multi-channel structural loading system.

[0076] The installation and use process of a loading experimental device for a novel quick-joint intelligent joint provided by the present invention is described as follows:

[0077] During installation, you can first prepare a table with a cross-section of 1000×600 as the base of the loading mechanism, and the loading mechanism body can be placed on the base; in the mortise and tenon joint, an LVDT displacement sensor is attached to the center of the upper and lower inner walls of the internal cavity of the female card connector 1. Note that a 2.5mm buffer is left at the front end of the LVDT displacement sensor. The installation should avoid the buffer zone and pull the wiring out from the other side of the camera 5 to avoid hindering the shooting; the outer side of the male card connector 2 uses the FBG fiber grating axial force gauge side package, and grooves slightly wider than the width of the optical fiber sensor are engraved on both sides of the I-shaped component of the male card connector 2. The FBG fiber grating axial force gauge is placed in the groove, and the fiber grating sensor is encapsulated with epoxy resin. The optical fiber line is led out from the bottom of the connector to measure the deformation information of the male card connector 2 connector in real time. The overall sensor layout position is as follows: Figure 1 As shown. Note that the lines leading out of each sensor should avoid right angles or loops to reduce signal transmission loss. The lines can be fixed with bayonet to prevent line shaking caused by loading.

[0078] refer to Figure 2, place the experimental camera 5 facing the side of the device, at a straight-line distance of 3 to 5m, spray an appropriate amount of polymer microspheres on the surface of the quick-joint to make it evenly distributed, mainly covering the sides of the collision positions of the C-type component and the I-type component, that is, the end positions of the sides photographed by the camera 5; the collision point is irradiated with a laser to facilitate the camera 5 to capture the displacement changes of the polymer microspheres. After applying different loads (such as bending or stretching) to the joint, a high-speed camera is used to record the movement trajectory of the particles during the experiment at a frame rate of 5000Fps, which is called digital image velocimetry, and is used to measure and analyze the extrusion deformation information of the male card joint 2 and the female card joint 1 during loading. During the experiment, the environment is kept at a constant temperature and humidity to avoid the influence of temperature and humidity on the experimental results.

[0079] After uploading the captured images to the computer, the data was processed using PIV lab. The time-resolved sequencing method was selected, and the CLAHE preprocessor was used to process the image data and perform noise reduction. The advantage is that when processing the image, the image contrast is more natural due to more balanced histogram pruning.

[0080] The loading mechanism of this experiment can realize loading in multiple different directions and can generate continuous and stable constant force loads to simulate the impact force during actual assembly; it is also convenient to simulate the force and displacement under other working conditions. The loading experiment device should also include a fixture, such as a manipulator, for clamping and fixing the quick-joint during the loading experiment. The loading mechanism and fixture are common structures in loading experiments and will not be described in detail.

[0081] The loading experiment specifically includes step-by-step loading experiment and actual working condition simulation loading experiment. The step-by-step loading experiment specifically includes:

[0082] Loading preparation: According to the characteristics and design requirements of the structural system, i.e. the quick-joint, determine the order of loading conditions and design the specific joint locations and directions of force application for each loading condition.

[0083] Preloading: Before actual loading, it is usually necessary to preload the structural system to check its initial state and performance. Preloading can be achieved by applying a certain load or deformation, generally about 50% of the maximum bearing capacity.

[0084] Perform step-by-step loading: After preloading, you can start step-by-step loading for the determined loading conditions. Each level of loading usually requires the following steps:

[0085] Determine the loading method: Determine the loading method according to the specific joint location and direction of force application designed according to the determined loading conditions.

[0086] Apply load: According to the loading method, apply corresponding load or deformation to simulate the actual working condition. Note that the difference between two adjacent levels of graded load should not exceed 1 / 10 of the maximum load or estimated ultimate bearing capacity.

[0087] Monitoring status: During the loading process, the above-mentioned mechanical property monitoring mechanism is used to monitor the stress, deformation and displacement of the structural system in real time. If an emergency occurs, loading should be stopped in time.

[0088] Analysis results: After loading is completed, the monitoring data needs to be analyzed and processed to evaluate the performance and stability of the structural system.

[0089] The loading conditions of the step-by-step loading experiment include: axial bending condition, applying a uniform load to the entire joint, measuring the overall bending moment and joint deformation; axial shear condition, applying a uniform load only to the male / female head area, measuring the shear force change; axial tensile condition, applying an axial reverse force to the female clamp joint 1 and the working clamp joint, and measuring the tensile deformation. Figure 3 This is the loading method for the shaft bending test; Figure 4 This is the loading mode for the axial tensile working condition experiment; the arrow in the figure indicates the loading direction. To facilitate the loading experiment, the first connecting member 6 can be connected and fixed to the female clamp joint 1, and the second connecting member 7 can be connected and fixed to the male clamp joint 2. When loading the axial bending working condition and axial shear working condition experiments, the first connecting member 6 and the second connecting member 7 can be fixed by a clamp to facilitate the axial bending loading experiment; when loading the axial tensile working condition experiment, the loading mechanism can be connected to the first connecting member 6 and the second connecting member 7 respectively, and the axial opposite force can be applied through the loading mechanism to facilitate the axial tensile loading experiment.

[0090] Simulate actual working conditions: After completing the step-by-step loading, you can conduct tests that simulate actual working conditions, such as sudden impacts during actual assembly, fire scenes, etc. By simulating actual working conditions, you can test the performance and reliability of the structural system under different working conditions.

[0091] It should be noted that during the loading process, adjustments and corrections should be made according to the actual situation to ensure the safety and stability of the structural system. At the same time, during the loading process, attention should be paid to protecting the structural system to prevent overload and damage.

[0092] In actual operation, the circuit should be connected first, and after testing that the readings of each sensor are normal, the loading condition should be set and the loading mechanism should be controlled to generate the corresponding loading force. In this process, the displacement, deformation, stress magnitude, etc. are automatically recorded and uploaded to the cloud through various sensors and camera 5, and the status of each data is displayed in real time through the display.

[0093] The loading test device and loading test method for a novel quick-joint intelligent joint provided by the present invention have the following advantages:

[0094] Easy to operate and install. The main body of the loading test device is placed on the basis of the existing mortise and tenon joints, and then perfected into a loading test device as a whole; at the same time, the measuring tools are simple and easy to use, which is convenient for on-site measurement;

[0095] The measurement accuracy is high. Multiple sensors are used in a set of experimental equipment to measure the same experiment. The error of each sensor is small, ensuring accurate measurement. At the same time, the environment is set to be indoors without interference, and the results are reliable and stable.

[0096] It fills the previously unknown gap in the professional field regarding mechanical testing of assembled pipe segment joints.

[0097] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A loading test device for quick-splicing joints, characterized in that: The quick-joint connector includes a female connector and a male connector, wherein the male connector is inserted into the open end of the female connector to realize the connection between the two, and the loading experimental device includes a mechanical property monitoring mechanism, wherein the mechanical property monitoring mechanism includes a first strain sensor disposed on the wall surface of the female connector and a second strain sensor disposed on the side surface of the male connector; The first strain sensor is used to obtain the deformation information of the female card joint when the quick-joint is subjected to a loading test, and the second strain sensor is used to obtain the deformation information of the male card joint when the quick-joint is subjected to a loading test, and then the mechanical properties of the quick-joint are obtained based on the deformation information of the female card joint and the deformation information of the male card joint.

2. The loading test device for quick-splicing joints according to claim 1, characterized in that: The female card connector includes two opposite walls, and the first strain sensors are fixedly arranged on the inner sides of the two opposite walls respectively; the second strain sensor is arranged on the male card connector along the insertion direction of the male card connector, and the second strain sensors are arranged on the two opposite side surfaces of the male card connector respectively.

3. The loading test device for quick-splicing joints according to claim 1, characterized in that: The first strain sensor is spaced apart from the opening end of the female card connector, so as to be spaced apart from the insertion end of the male card connector.

4. The loading test device for quick-splicing joints according to claim 1, characterized in that: A groove is provided on the side surface of the male card connector, and the second strain sensor package is arranged inside the groove.

5. The loading test device for quick-splicing joints according to any one of claims 1 to 4, characterized in that: The mechanical property monitoring mechanism also includes a camera arranged on one side of the quick-joint, and the camera is used to capture images of the plug-in connection surfaces of the female card connector and the male card connector when the quick-joint is subjected to a loading test, so as to obtain the extrusion deformation of the plug-in connection between the female card connector and the male card connector through image analysis.

6. A loading test method for quick-splicing joints, characterized in that: Based on the loading test device for quick-joints according to any one of claims 1 to 5, the loading test method comprises performing a step-by-step loading test on the quick-joints, and the step-by-step loading test on the quick-joints specifically comprises: Determining the loading conditions for the step-by-step loading test of the quick-joint; Arrange the load direction and the loading position according to the determined loading condition, and perform a step-by-step loading experiment in a step-by-step loading manner to obtain monitoring data of the mechanical property monitoring mechanism in each step of the loading experiment, wherein the step-by-step loading manner is a loading manner in which the load is gradually increased; The stress performance of the quick-joint under step-by-step loading conditions is obtained based on the monitoring data analysis of the mechanical property monitoring mechanism.

7. The loading test method for quick-splicing joints according to claim 6, characterized in that: Before the step-by-step loading experiment is carried out, the following steps are also included: The load loading direction and loading position are arranged according to the determined loading condition, and a preloading experiment is carried out. The preloading experiment is achieved by applying a preset load, wherein the preset load is 40%-60% of the maximum bearing capacity of the quick-joint under the determined loading condition.

8. The loading test method for quick-splicing joints according to claim 6, characterized in that: The loading conditions for the step-by-step loading test of the quick-joint joint include: Axial bending condition: applying a uniformly distributed load to the quick-joint as a whole, measuring the overall bending moment and the deformation of the quick-joint; Axial shear condition: applying a uniformly distributed load to the female clamp joint or the working clamp joint area, and measuring the shear force change; In the axial tensile condition, an axial reverse force is applied to the female card joint and the working card joint to measure the tensile deformation.

9. The loading test method for quick-splicing joints according to claim 6, characterized in that: After the quick-joint is subjected to a step-by-step loading test, the method further comprises: A loading experiment simulating actual working conditions is performed on the quick-joint, and the stress performance of the quick-joint under the simulation of actual working conditions is obtained based on the monitoring data of the mechanical property monitoring mechanism obtained in the experiment.

10. The loading test method for quick-splicing joints according to claim 6, characterized in that: The mechanical property monitoring mechanism also includes a camera, which is used to capture images of the plug-in connection surfaces of the female card connector and the male card connector when performing a loading test on the quick-joint connector, so as to obtain the extrusion deformation of the plug-in connection between the female card connector and the male card connector through image analysis. The loading test method also includes: Spray polymer microspheres on the surface of the quick-joint joint to evenly cover the opening end of the female connector and the insertion end of the male connector on the camera shooting surface, so that the camera can capture the displacement changes of the polymer microspheres; During the loading experiment, the shooting surface of the camera is illuminated by a laser, and the movement trajectory of the polymer microspheres during the experiment is recorded by the camera. The extrusion deformation of the male card connector and the female card connector during the loading experiment is obtained by analyzing the movement trajectory of the polymer microspheres during the experiment.

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