A loading experiment device and a loading experiment method for a quick splice joint

Abstract

The application belongs to the technical field of tunnel engineering, and discloses a loading experiment device and a loading experiment method for a quick splice joint, wherein the quick splice joint comprises a female card joint and a male card joint, the loading experiment device comprises a mechanical property monitoring mechanism, the mechanical property monitoring mechanism comprises a first strain sensor arranged on the wall surface of the female card joint and a second strain sensor arranged on the side surface of the male card joint; the first strain sensor is used for acquiring the deformation information of the female card joint during the loading experiment, the second strain sensor is used for acquiring the deformation information of the male card joint during the loading experiment, and then the mechanical property of the quick splice joint is analyzed and acquired according to the deformation information. The first strain sensor and the second strain sensor are arranged, so that the quick splice joint has the mechanical measurement function, the deformation information of the quick splice joint can be monitored and acquired during the loading experiment, and the mechanical property of the joint under the load can be acquired.

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 urban traffic congestion becoming increasingly severe, more and more cities have begun constructing subway projects. Shield machines, due to their minimal environmental impact, suitability for construction at great depths, high earth and water pressures, low cost, and wide applicability, have dominated urban subway construction and have become an indispensable general-purpose 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 the shield mechanism, but the mechanical properties of the segment joints are often overlooked. When the structure deforms, the load borne by the joints will change first, and under the influence of complex external environmental forces and thermal factors, the variation pattern of the 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 the segments by long-term monitoring of changes in joint preload; as well as the stress conditions of joints in special circumstances, such as fires. In traditional shield tunneling, joints exist only as structural components 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 response to 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 means to detect and obtain the stress performance of the segment joints under load. By setting up a mechanical performance monitoring mechanism, the mechanical properties of the quick-splicing joints can be analyzed and obtained in the loading experiment.

[0005] To achieve the above objectives, according to one aspect of the present invention, a loading test device for a quick-joint is provided. The quick-joint includes a female connector and a male connector. The male connector is inserted into the open end of the female connector to connect the two. The loading test device includes a mechanical property monitoring mechanism. The mechanical property monitoring mechanism includes a first strain sensor provided on a wall surface of the female connector and a second strain sensor provided on a side surface of the male connector.

[0006] The first strain sensor is used to obtain deformation information of the female card joint during a loading experiment on the quick splice joint, and the second strain sensor is used to obtain deformation information of the male card joint during the loading experiment on the quick splice joint, and then the mechanical properties of the quick splice joint are analyzed and obtained according to the deformation information of the female card joint and the deformation information of the male card joint.

[0007] According to the loading experiment device for the quick splice joint provided by the application, the female card joint comprises two opposite wall surfaces, and the first strain sensor is fixed on the inner side of each of the two wall surfaces.

[0008] According to the loading experiment device for the quick splice joint provided by the application, the first strain sensor is arranged at an interval from the open end of the female card joint, so as to be arranged at an interval from the insertion end of the male card joint.

[0009] According to the loading experiment device for the quick splice joint provided by the application, the side surface of the male card joint is provided with a groove, and the second strain sensor is packaged in the groove.

[0010] According to the loading experiment device for the quick splice joint provided by the application, the mechanical property monitoring mechanism further comprises a camera arranged on one side of the quick splice joint, and the camera is used to shoot an image of a plug-in connection surface of the female card joint and the male card joint during the loading experiment on the quick splice joint, so as to obtain extrusion deformation of the plug-in connection surface of the female card joint and the male card joint through image analysis.

[0011] According to another aspect of the application, a loading experiment method for a quick splice joint is provided, which is based on any one of the loading experiment devices for the quick splice joint, and the loading experiment method comprises a step-by-step loading experiment on the quick splice joint, and the step-by-step loading experiment on the quick splice joint specifically comprises:

[0012] determining a loading condition of the step-by-step loading experiment on the quick splice joint;

[0013] arranging a loading direction and a loading position according to the determined loading condition, and performing 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 loading experiment, wherein the step-by-step loading manner is a loading manner of gradually increasing the load;

[0014] analyzing and obtaining stress performance of the quick splice joint under the step-by-step loading condition according to the monitoring data of the mechanical property monitoring mechanism.

[0015] The loading experiment method for the quick splice joint provided by the application further comprises the following steps before the step of performing the step-by-step loading experiment in a step-by-step loading manner:

[0016] The preloading experiment is performed according to the determined loading condition, and the preloading experiment is realized by applying a preset load, wherein the preset load is 40%-60% of the maximum bearing capacity of the quick splice joint under the determined loading condition.

[0017] The loading experiment method for the quick splice joint provided by the application further comprises the following steps before the step of performing the step-by-step loading experiment in a step-by-step loading manner:

[0018] In the axial bending condition, uniform load is applied to the whole quick splice joint, and the overall bending moment and the deformation of the quick splice joint are measured;

[0019] In the axial shear condition, uniform load is applied to the region of the female connector or the male connector, and the shear force change is measured;

[0020] In the axial tension condition, opposite forces are applied to the female connector and the male connector along the axial direction, and the tensile deformation is measured.

[0021] The loading experiment method for the quick splice joint provided by the application further comprises the following steps before the step of performing the step-by-step loading experiment in a step-by-step loading manner:

[0022] The actual working condition simulation loading experiment is performed on the quick splice joint, and the stress performance of the quick splice joint under the actual working condition simulation is analyzed and obtained according to the monitoring data of the mechanical property monitoring mechanism obtained in the experiment.

[0023] The loading experiment method for the quick splice joint provided by the application further comprises the following steps before the step of performing the step-by-step loading experiment in a step-by-step loading manner:

[0024] Polymer microspheres are sprayed on the surface of the quick splice joint to uniformly cover the open end of the female connector and the insertion end of the male connector on the shooting surface of the camera, so as to facilitate the camera to capture the displacement change of the polymer microspheres;

[0025] During the loading experiment, the shooting surface of the camera is irradiated with laser, and the movement track of the polymer microspheres during the experiment is recorded by the camera, and the extrusion deformation of the male connector and the female connector during the loading experiment is analyzed and obtained according to the movement track 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 quick-splicing joints:

[0027] 1. By providing a first strain sensor and a second strain sensor, the quick-joint is equipped with a mechanical measurement function, which enables the deformation information of the quick-joint to be monitored and obtained during the loading test, thereby enabling the acquisition of the mechanical properties of the joint under load;

[0028] 2. Furthermore, the specific configuration of the first strain sensor and the second strain sensor does not affect the normal use of the male and female connectors, and can obtain strain information of the connectors at multiple locations, thereby enabling a more comprehensive and accurate analysis of the stress performance of the connectors.

[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 method can not only comprehensively and systematically obtain the mechanical properties of the quick-joint, but also specifically obtain the mechanical properties that need to be known in actual applications of the quick-joint, 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 view schematic diagram of the mechanical property monitoring mechanism provided by the present invention being arranged on a quick-splicing joint;

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

[0033] Figure 3 Schematic diagram of the load in the shaft bending loading experiment provided by the present invention;

[0034] Figure 4 Schematic diagram of the load of the axial tensile 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 objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining 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 may 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 includes a female card connector 1 and a male card connector 2, wherein the male card connector 2 is inserted into the open end of the female card connector 1 to achieve a connection between the two. The loading test device includes a mechanical property monitoring mechanism, wherein the mechanical property monitoring mechanism includes a first strain sensor 3 provided on the wall surface of the female card connector 1 and a second strain sensor 4 provided on the side surface of the male card connector 2;

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

[0040] In this embodiment, the female card connector 1 and the male card connector 2 are plugged in to achieve a quick-splicing connection. In order to detect and obtain the mechanical properties of the quick-splicing joint, this embodiment proposes that a loading test device can be set up to perform a loading test on the quick-splicing joint, thereby obtaining the mechanical properties of the quick-splicing joint under stress through the experiment, so as to provide guidance for the practical application of the quick-splicing joint. The specific loading test device is provided with a mechanical property monitoring mechanism for monitoring and obtaining the deformation information of the quick-splicing joint during the loading test, and then the mechanical properties of the quick-splicing joint can be obtained based on the deformation information.

[0041] Specifically, a first strain sensor 3 is provided on the female connector 1. The first strain sensor 3 is capable of detecting and acquiring the strain deformation occurring on the surface of the female connector 1 during the loading test. Based on this strain deformation, the mechanical properties of the quick-splicing joint can be analyzed by determining whether the deformation of the female connector 1 is within a preset range. Similarly, a second strain sensor 4 is provided on the male connector 2. The second strain sensor 4 is capable of detecting and acquiring the strain deformation occurring on the surface of the male connector 2 during the loading test, and the mechanical properties of the quick-splicing joint can be analyzed based on this strain deformation. By providing the first strain sensor 3 and the second strain sensor 4, the quick-splicing joint is equipped with a mechanical measurement function, capable of monitoring and acquiring deformation information of the quick-splicing joint during the loading test, thereby enabling the determination of the mechanical properties of the joint under load.

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

[0043] This quick-splicing joint can be used to connect shield segments. By conducting loading tests on the quick-splicing joint, the mechanical properties of the joint can be determined, providing guidance for the specific design and use of segment joints in practical applications. The quick-splicing 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 installed 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 respectively arranged on the two opposite side surfaces 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, and also spaced apart from the insertion end of the male connector 2. This prevents the male connector 2 from compressing and affecting the first strain sensor 3 when plugged into the female connector 1, thereby affecting the normal operation of the first strain sensor 3. In other words, the placement of the sensor does not affect the normal operation of the male and female connectors, and the connection of the male and female connectors does not affect the normal operation of the sensor.

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

[0047] Specifically, the first strain sensor 3 comprises an LVDT sensor; the second strain sensor 4 comprises a fiber Bragg grating (FBG) sensor. Two LVDT sensors, one on each of the upper and lower inner walls of the female connector 1, are mounted close to the inner wall. For example, a model GT50-10MM-V1 can be used. LVDT sensors offer high resolution and excellent sensitivity, with resolutions of less than 0.1 μm being suitable. They also offer high measurement accuracy and good repeatability, with linear accuracy reaching 0.25% being suitable. LVDT sensors also have excellent anti-interference performance and low output impedance, making them suitable for complex field environments.

[0048] The FBG fiber grating sensor uses a surface-welded fiber optic strain sensor or a surface-adhesive 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 carved 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 pre-known strain-stress relationship analysis. The axial direction is the insertion direction of the male connector 2, that is, Figure 1 The arrangement extension direction of the second strain sensor 4 is shown in FIG.

[0049] Fiber Bragg grating (FBG) sensors utilize optical fiber for signal transmission, offering strong resistance to electromagnetic interference. They also offer excellent electrical insulation, corrosion resistance, and high temperature resistance. They measure strain within a ±1500με range, achieve high measurement accuracy and sensitivity, reaching 0.1μm, and operate in a temperature range of -40°C to 80°C. The FBG sensor's structure consists of a prefabricated fiber connector, a 1.0mm seamless stainless steel tube, a single-point fiber Bragg grating (FBG) at the center, and a sealed / prefabricated fiber connector at the end. The FBG sensor utilizes a prefabricated fiber connector at the front and a sealed / prefabricated fiber connector at the rear. The front and rear connectors are connected by a single-point fiber Bragg grating (FBG). To protect the single-point FBG, a steel tube can be placed around it to prevent damage that could affect measurement and improve reliability.

[0050] Further, refer to Figure 2 The mechanical property monitoring mechanism also includes a camera 5 provided on one side of the quick-joint, and the camera 5 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 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 properties monitoring mechanism also includes a light source that cooperates with the camera 5. The light source uses a broadband tunable laser that can 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 can use CCD or CMOS imaging. Its optical imaging system incorporates an infrared cutoff filter (IR-cut filter, IRCF) to eliminate interference. The IRCF is an absorption-type filter, with a blue glass coating on the surface. The copper ions in the blue glass have a strong absorption effect on infrared light, resulting in good imaging effects.

[0052] Specifically, when camera 5 captures an image of the plug-in connection surface of female connector 1 and male connector 2, polymer microspheres can be sprayed on the open end of female connector 1 and the insertion end of male connector 2. The polymer microspheres should at least cover the open end of female connector 1 and the insertion end of male connector 2 on the camera 5's capture surface. This allows analysis of the displacement changes of the polymer microspheres in the captured image to analyze the extrusion deformation of the plug-in connection between female connector 1 and male connector 2. Images captured by camera 5 can be processed using PIV lab, and the image data can be processed using a CLAHE preprocessor. PIV lab and the CLAHE preprocessor are existing image processing methods and will not be described in detail here.

[0053] The camera 5 is capable of capturing the side surface of the cross section where the female connector 1 and the male connector 2 are connected. 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 apparatus for quick-joints also includes a loading mechanism, which is used to apply load to the quick-joint during the loading test. For example, a multi-channel loading mechanism can be used to enable loading in multiple directions. The loading mechanism can specifically be a hydraulic loading mechanism, such as a hydraulic cylinder, which uses an electro-hydraulic servo controller to convert electrical signals into hydraulic signals to precisely control the position, speed, and force of the loading mechanism. The loading mechanism system can also monitor execution status, for example by placing 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 apply loads in multiple directions. This can be achieved by setting up multiple loading mechanisms in different directions, or by setting up a robotic arm connected to the loading mechanism to change the direction of the load. This is used to simulate the impact force during actual assembly and also facilitates the simulation of forces and displacements 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 for analyzing and measuring joint deformation under different working conditions.

[0056] Furthermore, the present invention also provides a loading test method for a quick-splicing joint. The loading test method is based on any of the above-mentioned loading test devices for quick-splicing joints. The loading test method includes performing a step-by-step loading test on the quick-splicing joint. The step-by-step loading test on the quick-splicing joint specifically includes:

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

[0058] Arranging the load direction and loading position according to the determined loading condition, and performing 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-by-step loading experiment, wherein the step-by-step loading manner is a loading manner in which the load is gradually increased;

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

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

[0061] The load loading direction and loading position are arranged according to the determined loading conditions, 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-splicing joint under the determined loading conditions.

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

[0063] Axis bending working condition: applying a uniformly distributed load to the entire quick-splicing joint, measuring the overall bending moment and the deformation of the quick-splicing joint;

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

[0065] In the axial tensile working condition, forces in opposite directions along the axial direction are applied to the female card connector 1 and the working card connector, and the tensile deformation is measured.

[0066] Furthermore, after the quick-splicing 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 actual working condition simulation is obtained based on the monitoring data of the mechanical performance monitoring mechanism obtained in the experiment.

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

[0069] The loading test conditions for quick-splicing joints are divided into loading conditions for step-by-step loading tests and loading conditions for actual working condition simulation tests. The loading conditions for step-by-step loading tests are related to measuring the overall mechanical properties of quick-splicing joints. Through different step-by-step loading test loading conditions, the mechanical properties of quick-splicing joints in different directions can be systematically obtained, enabling a comprehensive measurement of the mechanical properties of quick-splicing joints. The loading conditions for actual working condition simulation tests are more targeted, targeting conditions where the mechanical properties of quick-splicing joints 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 obtain the mechanical properties of the quick-joint under some actual simulated working conditions in a targeted manner, which is 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.

[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 performing a loading test on the quick-joint, 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 to evenly cover the open 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 changes of the polymer microspheres;

[0073] During the loading experiment, the shooting surface of the camera 5 is illuminated with a 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-splicing 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 stress on the joint.

[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 ​​together, 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 new type of quick-joint intelligent joint provided by the present invention is described as follows:

[0077] During installation, a table with a cross-section of 1000×600 can be prepared 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 so as not to hinder the shooting; the outer side of the male card connector 2 adopts the FBG fiber grating axial force gauge side encapsulation, 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 wiring leading out of each sensor should avoid right angles or loops to reduce signal transmission loss. A bayonet can be used to secure the wiring to prevent it from shaking due to 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 5 meters, and spray an appropriate amount of polymer microspheres on the surface of the quick-joint to ensure uniform distribution, mainly covering the sides including the collision points of the C-shaped component and the I-shaped component, that is, the end positions of the sides photographed by the camera 5; the collision point is illuminated 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. This is called digital image velocimetry and is used to measure and analyze the extrusion deformation information of the male card connector 2 and the female card connector 1 during loading. Maintain a constant temperature and humidity during the experiment to prevent the influence of temperature and humidity on the experimental results.

[0079] After uploading the captured images to a computer, the data was processed using PIV Lab. Time-resolved sequencing was used, and the CLAHE preprocessor was used to process the image data for noise reduction. This has the advantage of more balanced histogram pruning and more natural image contrast.

[0080] The loading mechanism in this experiment is capable of loading in multiple directions and generating a continuous and stable constant force, simulating the impact forces experienced during actual assembly. This also facilitates simulation of forces and displacements under other working conditions. The loading experiment apparatus also includes a fixture, such as a manipulator, to secure 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 here.

[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 around 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 applied designed according to the determined loading conditions.

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

[0087] Monitoring status: During the loading process, the above-mentioned mechanical performance monitoring mechanism is used to monitor the stress, deformation and displacement of the structural system in real time. If an emergency occurs, the 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 card joint 1 and the working card joint, and measuring the tensile deformation. Figure 3 This is the loading method for the shaft bending test; Figure 4 This is the loading method for the axial tensile test; the arrow in the figure indicates the direction of the loading. To facilitate the loading test, a first connector 6 can be fixedly connected to the female connector 1, and a second connector 7 can be fixedly connected to the male connector 2. During the axial bending and shear test, the first and second connectors 6 and 7 can be secured with a clamp to facilitate the axial bending loading test. During the axial tensile test, a loading mechanism can be connected to the first and second connectors 6 and 7, respectively, and opposite axial forces can be applied through the loading mechanism to facilitate the axial tensile loading test.

[0090] Simulating actual working conditions: After completing the step-by-step loading, you can conduct tests simulating actual working conditions. For example, sudden impacts during assembly, fire scenarios, and other situations can be tested. By simulating actual working conditions, you can verify 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 actual conditions 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 the normal readings of each sensor, the loading condition should be set and the loading mechanism should be controlled to generate the corresponding loading force. During this process, the displacement, deformation, stress, 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 present invention provides a loading test device and a loading test method for a novel quick-joint intelligent joint, which have the following advantages:

[0094] The main body of the loading test device is easy to operate and install. The equipment is placed on the basis of the existing mortise and tenon joints, and then it is improved 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 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 merely 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 scope of protection of the present invention.

Claims

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

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 sensor is fixed 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 sensor is respectively provided on the two opposite side surfaces of the male card connector.

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 open 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. A loading test method for quick splicing joints, characterized in that: The loading test device for a quick-joint according to any one of claims 1 to 4 is used, wherein 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: Determining the loading conditions for the step-by-step loading test of the quick-splicing joint; Arranging the load direction and loading position according to the determined loading condition, and performing 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-by-step loading experiment, wherein the step-by-step loading manner is a loading manner in which the load is gradually increased; The mechanical performance of the quick-splicing joint under step-by-step loading conditions is obtained based on the monitoring data of the mechanical performance monitoring mechanism.

6. The loading test method for quick-splicing joints according to claim 5, 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 conditions, 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-splicing joint under the determined loading conditions.

7. The loading test method for quick-splicing joints according to claim 5, characterized in that: The loading conditions for the step-by-step loading test of the quick-joint include: Axis bending working condition: applying a uniformly distributed load to the entire quick-splicing joint, measuring the overall bending moment and the deformation of the quick-splicing joint; Axial shear condition: applying a uniformly distributed load to the female connector or the male connector area and measuring the shear force change; In the axial tensile working condition, forces in opposite directions along the axial direction are applied to the female card connector and the male card connector, and the tensile deformation is measured.

8. The loading test method for quick splicing joints according to claim 5, characterized in that: After the quick-splicing 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 actual working condition simulation is obtained based on the monitoring data of the mechanical performance monitoring mechanism obtained in the experiment.

9. The loading test method for quick-splicing joints according to claim 5, characterized in that: The mechanical property monitoring mechanism further 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, 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 further includes: Spray polymer microspheres on the surface of the quick-joint to evenly cover the open 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 with 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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