A comprehensive testing system and method for the impermeability of composite structure interfaces

Abstract

This invention discloses a comprehensive testing system and method for the waterproof performance of composite structure interfaces. The system includes a multi-field coupling test host for testing specimens, an intelligent control subsystem, a high water pressure control subsystem, a displacement control module, a rotation control module, a temperature control module, and a leakage monitoring module. The multi-field coupling test host integrates a multi-dimensional servo loading component, a temperature control fixture, a water injection sealing component, and an interface leakage detection component. It can independently or collaboratively apply temperature changes, normal / tangential / bending deformations, and high water pressure to thick-walled cylindrical composite interface specimens, simulating real service environments. Through multi-modal perception combining machine vision image acquisition and high-precision micro-weighing, the entire process of leakage initiation and propagation is visualized and quantitatively monitored. This invention achieves automated, programmable testing and intelligent evaluation of multi-physics coupling, providing a high-fidelity, mechanistic scientific evaluation method for the waterproof performance of composite structure interfaces.

Description

Technical Field

[0001] This invention relates to the field of civil engineering material testing and structural durability assessment technology, and in particular to a comprehensive testing system and method for the interfacial impermeability of composite structures. Background Technology

[0002] In major infrastructure projects such as tunnels, underground utility tunnels, reservoir dams, and cross-sea tunnels, the composite structural interfaces formed by combinations of different materials or the bonding of new and old concrete (such as construction joints, repair interfaces, and waterproofing layer bonding surfaces) are key weak points that determine the reliability and durability of the overall waterproofing system. Accurately assessing the impermeability of these interfaces in complex environments is fundamental to ensuring the safety and lifespan of the project.

[0003] Currently, laboratory testing methods for its impermeability have significant limitations, mainly including three categories: (1) Standard impermeability tester method: It adopts static and constant temperature test conditions, which cannot simulate the temperature changes and mechanical effects such as interface displacement and opening in actual engineering; and its "O-ring" static sealing method cannot maintain the seal when the specimen is deformed, which makes dynamic impermeability test impossible; at the same time, its endpoint criterion of "whether it is permeable" makes the test process "black box", making it difficult to reveal the failure mechanism. (2) Full-scale or model test: Although it is close to reality, it has problems such as high cost, long cycle, difficult control of variables, and non-repeatability, which are not suitable for material screening and mechanism research. (3) Multifunctional test machine for scientific research: It is usually temporarily set up, with low system integration, independent control of each factor (temperature, force, water pressure), difficulty in automatic coupling, and poor sealing reliability, which makes it impossible to standardize and promote.

[0004] In the field of materials testing, there are also devices that simulate complex loads. For example, the prior art CN107340190A discloses a multi-stage static and dynamic coupled mechanical loading device for high-frequency fatigue testing. This device belongs to the field of material micromechanical properties and fatigue testing. Its coupling object is mechanical stress at different frequencies. It aims to study the evolution of material microstructure. It does not involve direct observation and quantitative evaluation of fluid pressure loading, dynamic sealing under deformation, and interface leakage. Therefore, it cannot solve the problem of dynamic impermeability testing of interfaces under multi-field (temperature-deformation-water pressure) coupling in civil engineering. Summary of the Invention

[0005] The main objective of this invention is to provide a comprehensive testing system and method for the impermeability of composite structure interfaces, aiming to solve the problems that traditional testing methods are divorced from engineering practice and cannot reveal the failure mechanism.

[0006] To achieve the above objectives, the present invention provides a comprehensive testing system for the impermeability of composite structure interfaces. The system includes a multi-field coupling test host for testing specimens, an intelligent control subsystem, a high water pressure control subsystem, a displacement control module, a rotation control module, a temperature control module, and a leakage monitoring module.

[0007] The intelligent control subsystem is communicatively connected to the displacement control module, rotation control module, high water pressure control subsystem, temperature control module, and leakage monitoring module, respectively.

[0008] The multi-field coupling test host includes a multi-dimensional servo loading component for clamping and driving a specimen with a composite interface, a temperature control fixture for controlling the ambient temperature of the specimen, a water injection and sealing component for injecting water into and sealing the inner cavity of the specimen, and an interface leakage detection component for observing interface leakage of the specimen.

[0009] The multidimensional servo loading component includes a spatially independent but collaboratively controllable normal servo loading unit, a tangential servo loading unit, a left rotation servo loading unit, and a right rotation servo loading unit.

[0010] The displacement control module is electrically connected to the normal servo loading unit and the tangential servo loading unit in the multi-dimensional servo loading component; the rotation control module is connected to the left rotation servo loading unit and the right rotation servo loading unit in the multi-dimensional servo loading component.

[0011] The temperature control module is electrically connected to the temperature control fixture; the leakage monitoring module is electrically connected to the interface leakage detection component; and the high water pressure control subsystem is electrically connected to the water injection sealing component. Optionally, the specimen is a thick-walled cylindrical structure with a pre-set annular composite interface to be tested in the middle of its cylindrical wall. The specimen also has an axial cavity passing through the specimen interface. The fixing component includes a left fixing unit and a right fixing unit, with both ends of the specimen clamped by the left and right fixing units, respectively. Optionally, the specimen water injection sealing component includes an end cap body. The end cap body has a water injection pipe that penetrates it. One end of the water injection pipe is connected to the high water pressure control subsystem, and the other end extends into the axial cavity. The end cap body also integrates a pressure sensor and a temperature sensor.

[0012] Optionally, the interface leakage detection device includes at least four image acquisition devices arranged around the interface of the specimen, a funnel and a weighing device disposed below the specimen for collecting and weighing the leaked liquid. Optionally, the temperature control clamp is sleeved on the outside of the specimen; the temperature control clamp is a detachable clamp with an internal fluid circulation channel and is connected to an external constant temperature liquid circulation device through a fluid pipeline.

[0013] Optionally, the output ends of the left and right rotation servo loading units are connected to the left and right support platforms respectively, and are used to drive the left and right platforms to generate relative rotation; the normal servo loading unit is installed on the left support platform and drives the left end of the specimen to run perpendicular to the specimen interface through the normal deformation guide groove, and the tangential servo loading unit is installed on the right support platform and drives the right end of the specimen to run parallel to the specimen interface through the tangential displacement deformation guide groove, the tangential displacement guide groove, and the normal rod.

[0014] Optionally, the tangential servo loading unit is connected to the right side of the specimen through a tangential displacement guide groove and a normal limiting rod, wherein the normal limiting rod is used to constrain the normal degree of freedom during the tangential motion process.

[0015] Optionally, the intelligent control subsystem includes a central integrated controller and a host computer human-machine interface; the host computer is used to compile and input a coupled test instruction sequence containing a temperature loading program T(t), a mechanical deformation loading program D(t), and a hydraulic pressure loading program P(t); the central integrated controller is used to parse and execute the instruction sequence, and synchronously collect and store data from all sensors.

[0016] Furthermore, to achieve the above objectives, the present invention also provides a method for testing the impermeability of composite structure interfaces using the aforementioned comprehensive testing system, the method comprising the following steps:

[0017] Step 1: Compile a coupled test instruction sequence in the intelligent control subsystem, which includes a temperature loading program T(t), a mechanical deformation loading program D(t), and a hydraulic pressure loading program P(t);

[0018] Step 2: The intelligent control subsystem synchronously or sequentially drives the temperature control module, multi-dimensional servo loading component and high water pressure control subsystem to perform corresponding actions according to the instruction sequence.

[0019] Step 3: Simultaneously collect leakage images and leakage fluid quality data at the specimen interface through the leakage monitoring module, and simultaneously collect pressure and temperature data inside the specimen, as well as displacement and rotation data of each loading unit.

[0020] Step 4: Based on the collected data, analyze the coupling relationship between interface leakage behavior and temperature, deformation, and water pressure to determine the critical failure index.

[0021] Optionally, the critical failure index includes the critical deformation displacement or critical rotation angle that causes a step change in the leakage rate under constant temperature and pressure; or the critical water pressure that causes leakage at the interface under constant deformation.

[0022] Beneficial effects:

[0023] (1) Achieved high-fidelity simulation of multi-field coupling conditions: Through intelligent coordination control, the system can apply precise control of temperature field, complex stress field (normal, tangential, bending and their combination) and high water pressure field to the specimen synchronously or sequentially. It highly reproduces the harsh environment of "temperature-deformation-permeability" coupling at the joint interface in tunnels, pipe corridors and other projects on the laboratory scale, so that the test results are highly correlated with the actual project and solve the fundamental problem that the test conditions of traditional static permeability testers are divorced from reality.

[0024] (2) Overcoming the problem of high pressure sealing under dynamic deformation: By designing an integrated multi-functional end cap that integrates sensing and water injection functions, and adopting a sealing structure with compensation capabilities, the long-term stable sealing of the inner cavity of the specimen under high water pressure (such as above 0.5MPa) was successfully achieved during the process of millimeter-level active opening, displacement or bending deformation of the specimen interface, making the dynamic coupling test of "testing anti-permeability in deformation" possible.

[0025] (3) Achieved precise, visual, and quantitative monitoring of the leakage process: A multimodal perception scheme combining "vision + weighing" is adopted, which integrates high-definition industrial cameras arranged around the perimeter with a high-precision micro-electronic balance at the bottom. Machine vision can realize full-field, visual tracking and positioning of the initiation, convergence, and flow path of leaking water droplets; micro-weighing can realize precise measurement of milligram-level leakage and calculation of leakage rate. The fusion of the two data completely changes the traditional black-box endpoint judgment of "whether it is permeable", and realizes the dynamic revelation and quantitative evaluation of the leakage failure mechanism (starting position, expansion path).

[0026] (4) It provides a multi-dimensional, decoupled, and collaborative precision mechanical loading platform: through the spatially orthogonal and independently controlled normal and tangential servo loading units, as well as the symmetrically arranged left and right rotation servo loading units, combined with the constraints of high-rigidity guide grooves and normal limit rods, it can accurately and purely simulate the four basic stress states of tension, compression, shear and bending. It can also reconstruct arbitrary two-dimensional composite stress paths through complex vector superposition and trajectory planning by multi-axis motion controller, providing a powerful and flexible experimental means for studying and verifying the performance of interfaces under complex stress.

[0027] (5) Improved standardization, automation, and intelligence of testing: Through the unified scheduling of all functional modules by the intelligent control subsystem, users can compile "test recipes" containing T(t), D(t), and P(t) programs via the host computer. The system can then automatically execute complex multi-field coupled loading, synchronously collect data from all dimensions, and automatically analyze and generate test reports containing critical failure indicators (such as critical shear displacement and critical water pressure). This greatly improves testing efficiency, repeatability, and comparability of results, making the technology easy to standardize and promote. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a comprehensive testing system for the impermeability of a composite structure interface according to the present invention;

[0030] Figure 2 for Figure 1 A front view of the multi-field coupling test host structure;

[0031] Figure 3 for Figure 2 Top view of the main unit for multi-field coupling experiments;

[0032] Figure 4 for Figure 2 Side view of the main unit for multi-field coupling experiments;

[0033] Figure 5 for Figure 2 Front view of the pilot specimen;

[0034] Figure 6 for Figure 5 Side view of the pilot specimen;

[0035] Figure 7 for Figure 2 Front view of the specimen fixed by the fixing component

[0036] Figure 8 for Figure 7 Side view of the specimen secured by the fixing component;

[0037] Figure 9 for Figure 2 Side view of the medium temperature control fixture;

[0038] Figure 10 for Figure 2 Front view of the medium temperature control fixture;

[0039] Figure 11 for Figure 2 Top view of the medium temperature control fixture;

[0040] Figure 12 for Figure 2 Front view of the interface leakage monitoring component;

[0041] Figure 13 for Figure 2 Side view of the interface leakage monitoring component;

[0042] Figure 14 for Figure 2 Top view of the interface leakage monitoring component;

[0043] Figure 15 for Figure 2 Front view of the water injection sealing assembly;

[0044] Figure 16 for Figure 2 Top view of the water injection sealing assembly;

[0045] Figure 17 for Figure 2 Side view of the water-filled sealing assembly.

[0046] Explanation of icon numbers:

[0047] 1-Multi-field coupling test host; 2-Intelligent control subsystem; 3-High water pressure control subsystem; 4-Specimen;

[0048] 11-Left fixing unit; 12-Right fixing unit; 13-Fixing nut; 14-Right bolt; 15-Left bolt;

[0049] 21-Image acquisition device, 22-Weighing device, 23-Support bracket, 24-Ring bracket, 25-Function funnel;

[0050] 301 - High water pressure control module; 302 - Water bath tank; 303 - High water pressure pump;

[0051] 401 - Axial cavity, 402 - Right bolt hole, 403 - Left bolt hole, 404 Specimen interface;

[0052] 51-Upper clamp, 52-Lower clamp, 53-Cable;

[0053] 61-End cap body, 62-Water injection pipe, 63-Pressure and temperature sensor, 64-Signal line, 65-Water outlet pipe, 621-Water injection port, 622-Water inlet valve, 651-Water outlet valve;

[0054] 71-Normal servo loading unit, 72-Tangential servo loading unit, 73-Left rotation servo loading unit, 74-Right rotation servo loading unit, 701-Pressure and displacement sensor, 711-Normal deformation guide groove, 721-Tangential misalignment deformation guide groove, 722-Tangential displacement guide groove, 723-Normal limit rod, 731-Left side support platform, 741-Right side support platform;

[0055] 100 - Displacement control module, 200 - Rotation control module, 300 - Temperature control module, 400 - Leakage monitoring module.

[0056] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0057] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0058] See Figure 1-17 This invention provides a comprehensive testing system for the impermeability of composite structure interfaces. The system includes a multi-field coupling test host 1 for testing specimens, an intelligent control subsystem 2, a displacement control module 100, a rotation control module 200, a temperature control module 300, and a leakage monitoring module 400. The intelligent control subsystem 2 is communicatively connected to the displacement control module 100, the rotation control module 200, the temperature control module 300, and the leakage monitoring module 400.

[0059] The multi-field coupling test host 1 includes a fixing component for clamping the test specimen 4, a multi-dimensional servo loading component for driving the test specimen 4, a temperature control fixture for controlling the ambient temperature of the test specimen 4, a water injection sealing component for injecting water into and sealing the inner cavity of the test specimen 4, and an interface leakage detection component for observing interface leakage of the test specimen.

[0060] Furthermore, the displacement control module 100 is electrically connected to the normal and tangential servo loading units 71 and 72 in the multi-dimensional servo loading assembly, and is used to coordinately control the motion trajectory of the normal servo loading unit 71 and the tangential servo loading unit 72; the rotation control module 200 is electrically connected to the left and right rotation servo loading units 73 and 74 in the multi-dimensional servo loading assembly, and is used to coordinately control the rotation angle and direction of the left and right rotation servo loading units 73 and 74; the temperature control module 300 is electrically connected to the temperature control fixture; and the leakage monitoring module 400 is electrically connected to the interface leakage detection assembly.

[0061] Furthermore, the intelligent control subsystem 2 drives the corresponding modules to control the corresponding components in the multi-field coupling test host 1 to test the test specimen and acquire relevant data. The data is then fed back to the intelligent control subsystem 2 through the corresponding modules for regulation and analysis, thereby realizing the multi-dimensional analysis of the composite structure interface by the test system.

[0062] Furthermore, such as Figure 2-4As shown, the multidimensional servo loading assembly includes a spatially orthogonally arranged and independently controllable normal servo loading unit 71 and tangential servo loading unit 72, and a left rotation servo loading unit 73 and a right rotation servo loading unit 74 symmetrically arranged at both ends of the specimen; the normal servo loading unit 71 and the tangential servo loading unit 72 are each equipped with corresponding pressure and displacement sensors 701 for real-time recording of load and displacement data.

[0063] Specifically, the normal servo loading unit 71 is mounted on the left support platform 731 and drives the left end of the specimen to move in a direction perpendicular to the specimen interface 404 via the normal deformation guide groove 711, so as to apply a normal tensile or compressive load to the specimen interface 404. The output end of the normal servo loading unit 71 is connected to the left fixed unit 11 for driving the left end of the specimen. The tangential servo loading unit 72 is mounted on the right support platform 741 and drives the right end of the specimen to run parallel to the specimen interface 404 via the tangential displacement deformation guide groove 721, the tangential displacement guide groove 722, and the normal rod 723, so as to apply a shear load to the specimen interface 404. Preferably, both the normal servo loading unit 71 and the tangential servo loading unit 72 are electric servo actuators with built-in high-precision ball screws and planetary gear reducers. The actuators are equipped with force / torque sensors at their ends, which can not only measure axial loads but also monitor lateral forces and bending moments caused by installation deviations or uneven deformation of the specimen, ensuring the purity of the loading.

[0064] Furthermore, left and right rotation servo loading units 73 and 74, whose output ends are connected to the left and right support platforms 731 and 741 respectively, are used to drive the left and right platforms to generate relative rotation, so as to cause the specimen to bend and deform. The left and right rotation servo loading units 73 and 74 are precision servo geared motors and are equipped with circular grating encoders. Preferably, the left and right rotation servo loading units 73 and 74 are both mounted on the test base 16, and a level 17 is also installed on the test base.

[0065] Furthermore, the normal, tangential, and rotational servo loading units are preferably electric servo actuators or electro-hydraulic servo actuators, or they can be direct drive devices using linear motors.

[0066] Furthermore, the normal deformation guide groove 711 and the tangential misalignment deformation guide groove 721 are high-precision linear motion modules, and ultra-thin cross roller bearing turntables are provided below the left and right support platforms 731 and 741.

[0067] Furthermore, both the tangential displacement deformation guide groove 721 and the tangential displacement guide groove 722 are mounted on the right-side support platform 741. The normal deformation guide groove 711 is mounted on the left-side support platform 731.

[0068] Furthermore, the multi-dimensional servo loading component employs a serial independent loading mechanism. This involves the coordinated operation of multiple spatially separated and independently controlled kinematic chains (normal, tangential, and left / right rotation servos) to vector synthesize their respective motions at the specimen interface, ultimately approximating the required complex forces and motions. Alternatively, a parallel robot loading mechanism can be used, employing a highly integrated and compact parallel mechanism (such as a six-DOF Stewart platform) whose single-end output is directly connected to the specimen. By coordinating the control of all drive chains of this mechanism, any specified six-DOF spatial motion can be directly synthesized on its moving platform (i.e., the specimen connection end).

[0069] Furthermore, such as Figure 5-6 As shown, the specimen 4 is a thick-walled cylindrical structure with a pre-set annular composite interface 404 to be tested in the middle of its cylindrical wall. The specimen 4 has fixing components at both ends for connection. Specifically, an axial cavity 401 is formed in the middle of the specimen 4 through a core drill. The axial cavity 401 passes through the specimen interface 404 but does not penetrate the specimen 4. Multiple corresponding left and right bolt holes 403 and 402 are formed on the left and right sides of the specimen 4 through drilling, allowing the left (right) side of the specimen to be connected and fixed using the corresponding fixing components. Preferably, to ensure a tight connection between the fixing components and the specimen 4 without gaps, waterproof adhesive is used to seal the contact surfaces, ensuring that the fixing components do not leak under high water pressure.

[0070] Furthermore, specimen 4 is a thick-walled cylindrical specimen (with a central hole) instead of a solid cylinder or cube because cylindrical specimens have significant advantages such as uniform stress, clear sealing path, and convenient clamping. Specifically, (1) under the action of internal water pressure, the cylinder wall is in a state of uniform circumferential tensile stress, and the stress calculation is clear (based on the thick-walled cylinder theory), which is conducive to theoretical comparison. (2) Leakage can only occur along the only path - the annular interface in the middle of the cylinder wall, avoiding the complex edge leakage problem at the corners of the cubic specimen, making leakage monitoring purer and easier to interpret. (3) The two ends are flat, which facilitates connection with the clamp through flange bolts.

[0071] Furthermore, such as Figure 7-8The fixing assembly includes a left fixing unit 11 and a right fixing unit 12, which are respectively connected to the output end of the loading unit corresponding to the multi-dimensional servo loading assembly. Preferably, both the left fixing unit 11 and the right fixing unit 12 are sleeve structures, with one side of the left fixing unit 11 and the right fixing unit 12 being a flat surface and the other side being a concave surface. The two ends of the specimen 4 are respectively embedded in the corresponding concave surfaces of the left fixing unit 11 and the right fixing unit 12. The left and right fixing units 11 and 12 are also tightly connected to the ends of the specimen through corresponding left and right bolts 15 and 14 and fixing nuts 13. In order to ensure sealing, an appropriate amount of sealant is applied to the concave surface of the fixing assembly before connecting it to the end of the specimen 4 to ensure a good seal between the concave surface and the specimen 4 and to prevent leakage.

[0072] Furthermore, the temperature control fixture is fitted onto the outside of the specimen 4; specifically, as shown... Figure 9-11 As shown, the temperature control fixture consists of upper and lower fixtures 51 and 52, which are tightly connected by bolts. The specimen 4 is located in the middle of the heating fixture. The heating fixture contains a heating coil and a temperature sensor, and its surface is in close contact with the surface of the specimen 4 to facilitate heat transfer. Meanwhile, the lower fixture 52 is fixed to the corresponding support platform.

[0073] Furthermore, the upper and lower clamps 51 and 52 are both made of materials with high thermal conductivity (such as aluminum alloy or copper), and have precision-machined coiled flow channels inside. A circulating thermostatic liquid (oil or water) flows inside, thereby heating or cooling the clamps. The circulating thermostatic liquid (oil or water) is connected to an external thermostatic liquid circulation device through fluid pipelines. This heating method provides more uniform temperature, more stable control, and allows for rapid cooling (simulating freeze-thaw cycles) compared to resistance wire heating.

[0074] Preferably, the surfaces of the fixture that contact the specimen should have high flatness and be coated with thermally conductive silicone grease with high thermal conductivity to reduce contact thermal resistance. Additionally, ceramic fiber or vacuum insulation panels should be wrapped around the outside of the fixture to minimize heat loss and improve energy efficiency and temperature control accuracy.

[0075] Furthermore, miniature thermocouples or thermistors can be attached to key locations on the surface of the specimen (such as near the interface) to directly monitor the temperature of the specimen itself, which can then serve as a feedback signal for the temperature control system to ensure that the actual temperature of the specimen is consistent with the set value.

[0076] Furthermore, the interface leakage detection component includes at least four image acquisition units 21, a support bracket 23, a ring bracket 24, and a funnel 25, specifically, as follows: Figure 12-14As shown, the annular bracket 24 is fitted over the specimen interface 404 and mounted on the support bracket 23. A funnel 25 is also installed directly below the specimen interface 404. The top of the funnel 25 is connected to the annular bracket 24. The inner surface of the annular bracket 24 faces the specimen interface area to be tested. Multiple image acquisition devices 21 are fixedly mounted on the inner side of the annular bracket 24 or on the bracket connected to it.

[0077] Preferably, multiple image acquisition devices 21 are arranged around the specimen interface 404 of the specimen 4. The image acquisition devices 21 are high-definition cameras, preferably high-resolution industrial cameras. More preferably, four high-resolution industrial cameras equipped with macro lenses are used and evenly arranged around the specimen to capture images of the specimen interface area from different angles. Furthermore, a uniform, stable, and flicker-free LED cold light source is provided throughout the monitoring area to avoid shadows and reflections.

[0078] Furthermore, such as Figure 2 As shown, a weighing device 22 is also installed below the funnel 25, with the outlet of the funnel 25 directly aligned with the weighing area of ​​the weighing device 22, used to guide the collected leaked liquid to the weighing device 22 for weighing. The weighing device 22 is an electronic balance, preferably a microbalance with a resolution of 0.1 milligrams (0.0001 g), and is placed on an active air spring vibration isolation platform to isolate it from environmental vibration interference. The balance data is acquired in real time at a high frequency (e.g., 10 Hz).

[0079] Simultaneously, the high-definition camera inputs the captured image information into the leakage monitoring module, and the weighing device 22 transmits the measured leakage liquid mass information to the leakage monitoring module. This allows for data fusion and cross-validation between the visually estimated instantaneous leakage rate and the cumulative leakage amount obtained from the weighing system, significantly improving the accuracy and reliability of leakage monitoring, especially in determining initial leakage.

[0080] Furthermore, distributed fiber optic temperature sensors (DTS) or distributed fiber optic acoustic sensors (DAS) can be pre-embedded near the specimen interface or attached to the outer surface of the specimen. When leakage occurs, the intrusion of moisture will cause changes in the local temperature field (evaporation and heat absorption) or generate micro-vibrations (water droplets). These changes will be captured and located by the distributed fiber optic sensors. By monitoring the internal moisture migration process through distributed optical fibers, and simultaneously using visual and weighing systems to accurately calibrate the final leakage result, a comprehensive, multi-mechanism study of the entire process from the "inside" to the "outside" can be achieved.

[0081] Furthermore, multiple acoustic emission sensors can be arranged on the surface of the specimen or on the fixing components. During loading, not only will the dripping of leaking water droplets generate acoustic emission signals, but the generation and propagation of microcracks at the specimen interface will also generate richer acoustic emission signals. By analyzing the intensity, frequency, and location (time-difference positioning) of the acoustic emission signals, leakage events and damage events can be correlated. Furthermore, in the interface leakage detection component, while using vision and weighing devices to accurately record the time point and macroscopic results of leakage, the acoustic emission sensors can retrospectively analyze what specific damage events (such as a sudden increase in crack count, energy release) occurred in the interface region before and after that time point, thus establishing an irrefutable data bridge between phenomena and mechanisms. Further, such as... Figure 15-17 As shown, the water injection sealing assembly includes an end cap body 61, a water injection pipe 62, a pressure and temperature sensor 63, and a water outlet pipe 65. The end cap body 61 is adjustablely connected to the right-side fixing unit 12. Preferably, the end cap body 61 is screwed into the right-side fixing unit 12 of the specimen by rotation to form a seal. The right-side fixing unit 12 is provided with through holes around the circumference for the end cap body 61 to pass through.

[0082] Furthermore, the cover body 61 is provided with a water injection pipe 62 that penetrates it. One end of the water injection pipe 62 is connected to the high water pressure control subsystem 3, and the other end extends into the inner cavity (cavity 401) of the specimen 4. Preferably, the water injection pipe 62 is connected to the high water pressure control subsystem 3 through a water injection port 621 located at its end, and the water injection pipe 62 is also provided with a water inlet valve 622 in the area near the water injection port 621.

[0083] Furthermore, the cover body 61 is provided with a drainage channel, one end of which is connected to the inner cavity of the test piece 4, and the other end is connected to the water outlet pipe 65. Preferably, the water outlet pipe 65 is also provided with a water outlet valve 651, which can be used to vent air during the test preparation stage, and to drain water and depressurize during and at the end of the experiment.

[0084] Furthermore, the outlet pipe 65 can extend into the drainage channel and be flush with the other end face of the cover body 61.

[0085] Furthermore, the pressure sensor and temperature sensor 63 are integrated and packaged on the end cap body 61, with their sensing ends communicating with the pressurized flow channel or the inner cavity of the specimen to measure the actual water pressure and water temperature inside the cavity; the signal line 64 of the sensor is led out through a waterproof connector provided on the end cap body 61. The pressure sensor and temperature sensor 63 are preferably a miniature pressure sensor and a platinum resistance temperature sensor.

[0086] Furthermore, the water-filled sealing assembly can be integrated with the right-side fixing unit 12 into a single multi-functional end cap. A high-strength alloy steel end cap is used, and it is connected to the specimen end face via high-strength bolts with controllable preload. The connection surface is sealed with an elastomeric sealing ring, for example, a double O-ring sealing groove is designed, and sealant is applied to achieve a static seal. Preferably, in addition to relying on the elastic deformation of the sealing ring material (rubber, spring-loaded metal) itself to fill the microscopic gap between the sealing groove and the specimen end face to achieve a seal, a pressure medium can also be injected into the flexible bladder through an external air / liquid source, causing it to actively expand and deform, tightly adhering to the specimen surface and all sidewalls of the sealing groove to form a seal. For example, an air / hydraulic adaptive seal (air bladder / oil bladder) can be used, i.e., a flexible annular air bladder or oil bladder is installed in the sealing groove of the end cap or the right-side fixing unit. A medium of a certain pressure is injected into the bladder through an external air or hydraulic source, causing it to expand and tightly adhere to the specimen surface and the sidewalls of the sealing groove to form a seal.

[0087] In addition to the multi-bolt pre-tightening sealing method, the integrated multi-functional end cap can also generate uniform end-face clamping force through radial tightening of a ring clamp or circumferential pressing of several cam locking mechanisms. The driving method can be manual, hydraulic, or pneumatic. For example, a quick-release flange and clamp connection can be used instead of the multi-bolt pre-tightening connection. Furthermore, the high-pressure water control subsystem 3 includes a high-pressure water control module 301, a water bath 302, and a high-pressure water pump 303. The high-pressure water control module 301 is electrically connected to the intelligent control subsystem 2 to achieve intelligent water injection. That is, high-pressure water is directly injected into the sealed cavity (axial cavity 401) inside the specimen through the high-pressure water pump 303 and pipelines, actively establishing water pressure on one side of the interface. The water bath 302 is used to provide high-pressure water.

[0088] Furthermore, the intelligent control subsystem 2 includes a central integrated controller and a host computer human-machine interface; the host computer is used to compile and input a coupled test instruction sequence containing a temperature loading program T(t), a mechanical deformation loading program D(t), and a hydraulic pressure loading program P(t); the central integrated controller is used to parse and execute the instruction sequence, and synchronously collect and store data from all sensors.

[0089] Furthermore, a distributed cloud-edge collaborative system can be used for data processing. This involves deploying edge computing gateways and cloud platforms to asynchronously upload processed feature data for advanced analysis, visualization, and remote collaboration. For example, edge computing units can be integrated into each major sensor module for initial data filtering, feature extraction, and compression. The processed feature data is then uploaded to a cloud server via a high-speed network for fusion analysis, model training, and large-scale data storage. This approach is suitable for modern intelligent laboratories with multiple networked devices, large data volumes, and the need for online training and updates of artificial intelligence models. It can reduce the computational burden on local hosts and facilitate data sharing and remote collaboration.

[0090] Furthermore, the present invention also provides a method for testing the impermeability of a composite structure interface using the aforementioned integrated testing system, the method comprising the following steps:

[0091] Step 1: Compile a coupled test instruction sequence in the intelligent control subsystem, which includes a temperature loading program T(t), a mechanical deformation loading program D(t), and a hydraulic pressure loading program P(t);

[0092] Step 2: The intelligent control subsystem synchronously or sequentially drives the temperature control module, multi-dimensional servo loading component and high water pressure control subsystem to perform corresponding actions according to the instruction sequence.

[0093] Step 3: Simultaneously collect image data at the specimen interface, leakage liquid mass data, internal pressure and temperature data of the specimen, and displacement and force data of each loading unit through the leakage monitoring module.

[0094] Step 4: Based on the collected data, analyze the coupling relationship between interface leakage behavior and temperature, deformation, and water pressure to determine critical failure indicators. These critical failure indicators include the critical shear displacement or critical normal opening displacement that causes a step change in the leakage rate under constant temperature and pressure; or the critical water pressure that causes interface leakage under constant deformation.

[0095] To better illustrate the systematic effects of the present invention, the following description is provided through specific embodiments.

[0096] Example 1 - Multi-field coupling durability test of the sealing system for the subsea immersed tunnel joint

[0097] 1. Test Objectives and Operating Conditions

[0098] Project Background: A cross-sea immersed tunnel has a maximum water depth of 50 meters and a minimum seawater temperature of 5℃. The tunnel segment joints may experience long-term, slow displacement and opening due to geological conditions.

[0099] Simulation conditions: Temperature field (T): Constant 5℃ (simulating low sea surface temperature). Water pressure field (P): Hydrostatic pressure 0.5 MPa (simulating 50-meter water head pressure). Mechanical deformation field (D): Shear displacement (D... s ): Simulating long-term settlement, a final displacement of 2.5 mm is applied at an extremely slow rate. Normal opening (D n During the shearing process, a periodic opening / closing cycle with an amplitude of 0.2 mm is superimposed to simulate the joint micro-movement caused by tidal load.

[0100] Test objective: To determine the critical failure shear displacement and leakage rate development law of the sealing interface under the above coupled working conditions.

[0101] 2. Specimen preparation and system setup

[0102] 2.1 Preparation of Simulated Specimens

[0103] Substrate fabrication: Two thick-walled cylindrical specimens of C60 high-strength concrete, each with an outer diameter of 150 mm, an inner diameter of 60 mm, and a height of 250 mm, were prepared. Half of the cross-section of a standard GINA-type rubber waterstop was pre-embedded in the casting at the end face of one of the specimens, forming a pre-embedded interface.

[0104] Interface construction: The clean end face of another concrete cylindrical specimen is joined with the end face of the pre-embedded semi-cutoff water strip. A special adhesive is applied to the mating surfaces, and constant pressure is applied on a special centering clamp for curing to form a complete "concrete-rubber-concrete" composite interface specimen. High-strength threaded sleeves are pre-embedded at both ends of the specimen.

[0105] Sensor pre-embedding: Distributed optical fiber sensing cables are pre-embedded in the concrete area 10mm from the interface to monitor the strain distribution near the interface during the test.

[0106] 2.2 Assembly and Debugging of the Test System

[0107] Core component installation: Connect the prepared composite specimen to the integrated multi-functional end cap assembly via threaded sleeves at both ends. Tighten the connecting bolts to the specified torque using a torque wrench to ensure the double O-ring seal between the end cap and the specimen end face is in place.

[0108] Loading system connection: Connect specimen 4 to the multi-dimensional servo loading assembly. The multi-dimensional servo loading assembly integrates a tangential servo loading unit (for applying D... s ) and normal servo loading unit (for applying D n ).

[0109] Environmental and Monitoring System: The assembled specimen assembly is placed in a temperature control fixture, with the fixture's circulating fluid circuit connected to a high-precision programmable constant-temperature liquid bath 302. The water injection pipe 62 of the water injection sealing assembly is connected to the outlet of the high-pressure water control subsystem 3, and the outlet pipe is connected to an outlet valve 651 to simulate a constant water head. Interface Leakage Monitoring Component Installation: A ring-shaped bracket 24 with four high-definition macro cameras is fitted over the specimen interface 404, and the focus and illumination are adjusted. A superhydrophobic flow-guiding funnel 25 is installed directly below the specimen, with its outlet aligned with the weighing dish of a microbalance with a precision of one part per million placed on an air spring vibration isolation platform.

[0110] System integration and sealing check: Start the intelligent control system and perform zero-point calibration of each sensor and zeroing of the motion mechanism. Close the outlet valve 651, and slowly inject water into the inner cavity of the specimen through the high-pressure water control subsystem 3 and pressurize it to 0.2 MPa (lower than the test pressure), and maintain the pressure for 30 minutes. During this period, check for leaks at each connection point, observe whether the balance reading is stable, and confirm that the sealing system is intact.

[0111] 3. Experimental Procedure Execution and Data Acquisition

[0112] 3.1 Programmable Loading Program Settings

[0113] An automated test program named "Seal_Endurance_Test_01" was developed in the control software, and its core timing sequence is as follows:

[0114] Time axis (t): 0-120 min: Start the constant temperature liquid bath to uniformly cool the fixture and specimen from room temperature to and stabilize at 5.0 ± 0.5℃. 120-150 min: Start the high-pressure water pump to increase the internal water pressure to 0.5MPa at a rate of 0.01 MPa / s, and enter the closed-loop pressure stabilization mode. 150 min start: Start the mechanical loading cycle.

[0115] Tangential displacement (Ds): Continuous rightward displacement at a rate of 0.001 mm / s (simulating slow settlement).

[0116] Normal displacement (Dn): A sinusoidal displacement with an amplitude of ±0.1 mm (total opening 0.2 mm) and a period of 600 s is superimposed. This continues until the total tangential displacement reaches 3.0 mm or a leakage failure alarm is triggered. Simultaneously, data acquisition parameters are set: all channels (temperature, pressure, 6-dimensional force, multi-channel displacement, image, balance mass) are simultaneously acquired at a frequency of 10Hz.

[0117] 3.2 Automated Test Execution

[0118] The operator clicks to start the "Seal_Endurance_Test_01" program on the HMI.

[0119] The system automatically executes the following steps in sequence: cooling and pressurization. During the temperature and water pressure stabilization phase, the initial leakage rate (background value) is recorded as Q0 (≈0 mg / min).

[0120] Automatic mechanical loading starts. Real-time screen display: multi-axis displacement-time curve; water pressure and temperature curves (two stable straight lines); real-time leakage quality-time curve and calculated instantaneous leakage rate curve; four-channel camera feeds, with selectable image merging or split-screen display.

[0121] 4. Observation and Key Data During the Experiment

[0122] 4.1 Process Observation

[0123] When the shear displacement Ds reached approximately 2.05 mm, a tiny, stable water droplet (approximately 0.5 mm in diameter) was observed for the first time in the lower right quadrant of the high-definition camera image. The machine vision algorithm automatically recognized and marked the event, displaying a notification box.

[0124] Data from the microbalance showed that, almost simultaneously, the cumulative mass curve exhibited a stable upward slope exceeding the noise level. As Ds continued to increase to 2.45 mm, the number of water droplets increased and began to appear in series, dripping. The leakage rate curve showed an exponential upward trend.

[0125] 4.2 Safety and Termination

[0126] The system's preset "leakage rate over-limit alarm threshold" is 1.0 g / min. When Ds ≈ 2.60 mm, the instantaneous leakage rate exceeds the threshold, and the control system automatically triggers a safety protocol: immediately stops all displacement loading, maintains the current Ds and Dn displacement values, and continues to maintain water pressure. The system records this moment as a "significant failure point".

[0127] 5. Data Processing and Result Analysis

[0128] After the experiment, the system software automatically generated a comprehensive report, with key analyses as follows:

[0129] Leakage Characteristic Curve: Plot the relationship curve of "leakage rate (Q) - shear displacement (Ds)". The curve clearly shows that when Ds < 2.05 mm, Q ≈ 0 (perfect seal). When Ds = 2.05 mm, an inflection point appears, and Q becomes measurable (initial leakage point). After Ds > 2.45 mm, Q rises sharply (rapid leakage development zone). Judgment: Under the temperature and pressure set in this test, the critical shear displacement for engineering safety of this waterstop joint is approximately 2.05 mm; the failure displacement is approximately 2.60 mm.

[0130] Multi-field data correlation: Correlation of strain data from distributed optical fibers with Ds and Dn revealed that when Ds exceeds 2.0 mm, the tensile strain of the concrete near the interface increases sharply, closely coinciding with the leakage initiation point, revealing the mechanism of "material damage leading to seal failure". The periodic variation of Dn caused slight periodic fluctuations in the leakage rate, intuitively demonstrating that alternating opening loads accelerate leakage.

[0131] Visualized report: The report automatically includes a high-resolution image sequence of key time points from initial seepage to failure, a 3D "displacement-time-leakage" relationship cloud map, and raw data tables for each sensor.

[0132] The above embodiments fully demonstrate how the system of the present invention can be used to solve a specific and complex engineering problem. Through a single automated test, quantitative performance boundaries under coupled effects are obtained, which traditional methods would require multiple isolated experiments to piece together and cannot achieve.

[0133] Furthermore, rubber specimens with different formulations and hardnesses can be used for material comparison and screening. The constant-temperature water can be replaced with a solution containing 3.5% NaCl, and the test can be repeated to evaluate the effect of chloride ion corrosion on the long-term performance of the sealing material. The program can be modified to maintain a long-term load (e.g., 1000 hours) after reaching a certain displacement, and the change in leakage rate over time can be monitored to evaluate the effects of stress relaxation and creep on sealing performance.

[0134] This embodiment fully demonstrates that the test system and method provided by the present invention are not only a set of precise testing equipment, but also a powerful platform for engineering problem research and product development, which can provide full-chain data support from materials to design for the waterproof safety of major infrastructure.

[0135] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A comprehensive testing system for the interfacial impermeability of composite structures, characterized in that, The system includes a multi-field coupling test host (1) for testing specimens, an intelligent control subsystem (2), a high water pressure control subsystem (3), a displacement control module (100), a rotation control module (200), a temperature control module (300), and a leakage monitoring module (400). The intelligent control subsystem (2) is communicatively connected to the displacement control module (100), rotation control module (200), high water pressure control subsystem (3), temperature control module (300) and leakage monitoring module (400), respectively; The multi-field coupling test host (1) includes a multi-dimensional servo loading component for clamping and driving a specimen (4) with a composite interface, a temperature control fixture for controlling the ambient temperature of the specimen (4), a water injection sealing component for injecting water into and sealing the inner cavity of the specimen (4), and an interface leakage detection component for observing leakage at the interface (404) of the specimen. The multidimensional servo loading component includes a spatially independent and collaboratively controllable normal servo loading unit (71), a tangential servo loading unit (72), a left rotation servo loading unit (73), and a right rotation servo loading unit (74). The displacement control module (100) is electrically connected to the normal servo loading unit (71) and the tangential servo loading unit (72) in the multi-dimensional servo loading component; the rotation control module (200) is connected to the left rotation servo loading unit (73) and the right rotation servo loading unit (74) in the multi-dimensional servo loading component; The temperature control module (300) is electrically connected to the temperature control fixture; the leakage monitoring module (400) is electrically connected to the interface leakage detection component; and the high water pressure control subsystem (3) is electrically connected to the water injection sealing component.

2. The comprehensive testing system according to claim 1, characterized in that, The specimen (4) is a thick-walled cylindrical structure with a pre-set annular composite interface (404) to be tested in the middle of its cylindrical wall. The specimen (4) is also provided with an axial cavity (401) passing through the specimen interface (404). The fixing component includes a left fixing unit (11) and a right fixing unit (12). The two ends of the specimen (4) are clamped by the left fixing unit (11) and the right fixing unit (12) respectively.

3. The comprehensive testing system according to claim 2, characterized in that, The specimen water injection sealing assembly includes an end cap body (61), and the end cap body (61) is provided with a water injection pipe (62) that penetrates it. One end of the water injection pipe (62) is connected to the high water pressure control subsystem (3), and the other end extends into the axial cavity (401). The end cap body (61) also integrates a pressure sensor and a temperature sensor (63).

4. The comprehensive testing system according to claim 1, characterized in that, The interface leakage detection device includes at least four image acquisition devices (21) arranged around the interface (404) of the specimen, a funnel (25) and a weighing device (22) arranged below the specimen (4) for collecting and weighing the leaked liquid.

5. The comprehensive testing system according to claim 1, characterized in that, The temperature control clamp is fitted over the outside of the specimen (4); the temperature control clamp is a detachable clamp with a fluid circulation channel inside, and is connected to an external constant temperature liquid circulation device through a fluid pipeline.

6. The comprehensive testing system according to claim 1, characterized in that, The left and right rotation servo loading units (73, 74) have their output ends connected to the left and right support platforms (731, 741) respectively, and are used to drive the left and right platforms to generate relative rotation; the normal servo loading unit (71) is installed on the left support platform (731) and drives the left end of the specimen to run perpendicular to the specimen interface (404) through the normal deformation guide groove (711); the tangential servo loading unit (72) is installed on the right support platform (741) and drives the right end of the specimen to run parallel to the specimen interface (404) through the tangential displacement deformation guide groove (721), the tangential displacement guide groove (722), and the normal rod (723).

7. The comprehensive testing system according to claim 6, characterized in that, The tangential servo loading unit (72) is connected to the right side of the specimen through a tangential displacement guide groove (722) and a normal limiting rod (723). The normal limiting rod (723) is used to constrain the normal degree of freedom during the tangential motion process.

8. The comprehensive testing system according to claim 1, characterized in that, The intelligent control subsystem includes a central integrated controller and a host computer human-machine interface; the host computer is used to compile and input a coupled test instruction sequence containing a temperature loading program T(t), a mechanical deformation loading program D(t), and a hydraulic pressure loading program P(t); the central integrated controller is used to parse and execute the instruction sequence, and synchronously collect and store data from all sensors.

9. A method for testing the impermeability of a composite structure interface using the comprehensive testing system described in any one of claims 1-8, characterized in that, The method includes the following steps: Step 1: Compile a coupled test instruction sequence in the intelligent control subsystem, which includes a temperature loading program T(t), a mechanical deformation loading program D(t), and a hydraulic pressure loading program P(t); Step 2: The intelligent control subsystem synchronously or sequentially drives the temperature control module, multi-dimensional servo loading component and high water pressure control subsystem to perform corresponding actions according to the instruction sequence. Step 3: Simultaneously collect leakage images and leakage fluid quality data at the specimen interface through the leakage monitoring module, and simultaneously collect pressure and temperature data inside the specimen, as well as displacement and rotation data of each loading unit. Step 4: Based on the collected data, analyze the coupling relationship between interface leakage behavior and temperature, deformation, and water pressure to determine the critical failure index.

10. The test method according to claim 9, characterized in that, The critical failure index includes the critical deformation displacement or critical rotation angle that causes a step change in the leakage rate under constant temperature and pressure; or the critical water pressure that causes leakage at the interface under constant deformation.

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