Device and method for detecting interface debonding of hydraulic concrete structure repaired by FRP (Fiber Reinforce Plastic)

Abstract

The invention discloses a device and a method for detecting interface debonding of a hydraulic concrete structure repaired by FRP, and relates to the field of intelligent operation and maintenance of hydraulic engineering, the device comprises a probe and a host, the probe integrates acoustic detection and piezoelectric ceramic implantation functions, and can strike over the FRP surface and rapidly and preliminarily screen a debonding area through sound signal abnormity, and the probe is used for detecting the interface debonding of the hydraulic concrete structure repaired by the FRP. Precisely implanting a piezoelectric ceramic sensor and a matched curing agent into the debonding part by using the same probe to form a long-term monitoring point; by means of the method, the integrated operation process of rapid initial detection, fixed-point implantation and key detection is achieved. According to the invention, reliable implantation and stable signal acquisition of piezoelectric ceramics are realized, the problem of disjunction between detection of a traditional method and long-term monitoring and later detection is solved, and the device has the advantages of high integration level, capability of long-term fixed-point tracking and high applicability.

Description

Technical Field

[0001] This invention belongs to the field of intelligent operation and maintenance of water conservancy projects, and in particular, it relates to a method for testing the repair performance of hydraulic concrete structures, especially a device and method for testing interface debonding of FRP-repaired hydraulic concrete structures. Background Technology

[0002] In the long-term maintenance of water conservancy infrastructure, hydraulic concrete structures are prone to damage due to environmental erosion, load fatigue, and material aging. Adhesive reinforcement with fiber-reinforced polymer (FRP) composites has become a common repair method. FRP repair technology can effectively improve the load-bearing capacity and durability of structures, but its repair effect largely depends on the integrity of the bond between the FRP and the concrete matrix. Interface debonding is a common defect in FRP reinforcement systems; once it occurs, it significantly reduces the repair effect and may even lead to reinforcement failure, threatening structural safety.

[0003] Currently, the main methods for detecting debonding at the interface of FRP repair layers include traditional non-destructive testing techniques such as impact testing, infrared thermography, and ultrasonic testing. While these methods can identify debonding areas to some extent, they still have significant limitations: impact testing relies on human experience, is highly subjective, and is difficult to quantify; infrared thermography is greatly affected by ambient temperature and surface condition, limiting its applicability in complex hydraulic environments; and ultrasonic testing requires high surface flatness and coupling conditions, and typically only allows for single-point or localized scanning, making it difficult to achieve long-term, dynamic monitoring of the interface condition. More importantly, existing methods are mostly limited to the "detection-identification" stage, unable to perform timely repairs upon discovering debonding, nor can they continuously perceive and evaluate the interface condition after repair, resulting in repair and maintenance work remaining in an outdated "passive response, repetitive testing" mode.

[0004] Therefore, there is an urgent need for an intelligent method that can integrate "detection-repair-key detection" to improve the reliability and life-cycle maintenance efficiency of FRP detection systems.

[0005] A review reveals numerous publicly available technologies for detecting interface debonding in FRP repair of hydraulic concrete structures, but none specifically address subsequent key testing methods for interface debonding. The following are some publicly available solutions:

[0006] Chinese Patent CN120971576A discloses a phased array ultrasonic method for detecting interface debonding in multilayer curved surface bonded structures, which can accurately determine interface debonding defects. Chinese Patent CN118090829A discloses a non-destructive testing method and equipment for fiber cloth debonding defects, enabling the detection of FRP bonding conditions, improving the detection rate and accuracy of debonding defects, and increasing testing efficiency. Chinese Patent CN114235957B discloses a method for detecting interface debonding defects in multilayer bonded structures, achieving accurate identification of debonding defects and solving the problems of low accuracy and difficulty in detecting defects using impact testing and ultrasonic testing. Chinese Patent CN112577933B discloses a fluorescent detection method for interface debonding in fiber-reinforced polymer composites, which can quickly, accurately, and visually detect whether fiber-reinforced polymer composites have debonding damage. The aforementioned publicly available technologies all focus on how to efficiently and accurately measure interface debonding, but neglect the subsequent key detection of the debonding area, and do not provide a usable integrated "detection-repair-key detection" device and method.

[0007] Therefore, there is an urgent need for a detection device and method for interface debonding in FRP repair of hydraulic concrete structures, which can realize the "detection-repair-key detection" of interface debonding in FRP repair of hydraulic concrete structures. Summary of the Invention

[0008] The purpose of this invention is to provide a device and method for detecting interface debonding of FRP repaired hydraulic concrete structures, so as to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A device for detecting interface debonding in FRP repair of hydraulic concrete structures, characterized in that the device includes a probe and a main unit.

[0011] Furthermore, the probe generates an acoustic signal by tracing across the FRP surface, and the abnormal acoustic signal caused by the interface debonding zone generated by the hydraulic concrete structure under the FRP is received and identified by the host.

[0012] Preferably, a solid component can be added to the injection port of the probe, which can be fitted onto the injection port and slide across the FRP to avoid wear on the injection port.

[0013] Preferably, the host integrates an acoustic signal preprocessor and an intelligent recognition module, which can analyze the frequency and amplitude characteristics of the acoustic signal in real time, and preliminarily screen out suspected debonding areas through algorithms, providing operators with audio-visual prompts and improving the efficiency and accuracy of the preliminary screening.

[0014] Preferably, the host computer is equipped with a wireless communication module, which can transmit the collected acoustic signal data and analysis results to a cloud server or mobile terminal in real time, facilitating data archiving, remote diagnosis, and comparative analysis of multi-round monitoring data.

[0015] Furthermore, the probe includes a piezoelectric ceramic wire, a piezoelectric ceramic push valve, a curing agent push plate, a piezoelectric ceramic integrated core, a hinged seal, an injection needle port, a curing agent mixing chamber, a curing agent extrusion valve, a curing agent placement chamber, and a curing agent push valve.

[0016] Preferably, the piezoelectric ceramic wire is connected to the tail end of the piezoelectric ceramic integrated core to transmit the FRP surface acoustic signal to the host.

[0017] Preferably, the piezoelectric ceramic wires are multi-stranded and separate, with each piezoelectric ceramic fitted on the piezoelectric ceramic integrated core connected to a wire, which is led out from the hollow core of the piezoelectric ceramic integrated core and remains on the surface of the structure as the piezoelectric ceramic is injected into the debonding point.

[0018] Preferably, the piezoelectric ceramic conductor is covered with a flexible and corrosion-resistant insulating sheath, the color of which can be distinguished from the FRP surface color, facilitating the identification and location of the conductor outlet during long-term monitoring.

[0019] Preferably, the piezoelectric ceramic push valve is connected to the piezoelectric ceramic integrated core and is used to squeeze the piezoelectric ceramic on the piezoelectric ceramic integrated core into the interface debonding zone.

[0020] Preferably, the curing agent pusher plate is disposed in the curing agent storage cavity, and its top end is connected to the curing agent pusher valve to squeeze the curing agent out of the curing agent extrusion valve and into the curing agent mixing cavity. After mixing, it is squeezed out from the injection needle and squeezed into the interface debonding zone.

[0021] Preferably, the curing agent is a fast-curing two-component resin, and the curing agent mixing chamber is equipped with a static mixer to ensure that the two components are fully and evenly mixed before extrusion, so as to ensure rapid curing and stable fixation of the piezoelectric ceramic.

[0022] Preferably, the curing agent storage cavity is a detachable storage cylinder, which facilitates filling or replacing the curing agent material before use and adapts to different curing times or ambient temperatures.

[0023] Preferably, the hinged seal is located at the head of the piezoelectric ceramic integrated core. During the extrusion of the piezoelectric ceramic, the hinged seal can rotate and seal the channel from the curing agent mixing chamber to the injection needle port, thereby isolating the curing agent during the extrusion of the piezoelectric ceramic and preventing the curing agent from mixing with the piezoelectric ceramic prematurely.

[0024] Preferably, the hinged opening is equipped with a miniature torsion spring on its rotating shaft to ensure that it can automatically return to the position of sealing the injection channel when no external force is applied, thus preventing accidental leakage or backflow of the curing agent.

[0025] Furthermore, the piezoelectric ceramic integrated core also includes a piezoelectric ceramic integrated core shell, a rotating shaft, piezoelectric ceramic push teeth, a spring, and piezoelectric ceramic.

[0026] Preferably, a rotating shaft is fixed inside the piezoelectric ceramic integrated core housing to fix the top of the piezoelectric ceramic pusher tooth, so that the piezoelectric ceramic pusher tooth rotates around the rotating shaft.

[0027] Preferably, a spring connects the back side of the two piezoelectric ceramic pusher teeth for resetting the piezoelectric ceramic pusher teeth.

[0028] Preferably, the piezoelectric ceramic integrated core housing is fitted with multiple piezoelectric ceramics. After the piezoelectric ceramic pushing teeth push one piezoelectric ceramic, it is reset and then pushes the next piezoelectric ceramic.

[0029] Preferably, the piezoelectric ceramic is in the form of a sheet or column, and its surface may be pre-coated with an insulating layer but the conductive layer at the end is exposed, so as to ensure that after implantation, it can not only bond well with the curing agent, but also form an effective electrical connection through the wire.

[0030] Preferably, the piezoelectric ceramic integrated core shell is made of a transparent or semi-transparent material, which makes it easy for the operator to observe the remaining quantity and pushing status of the internal piezoelectric ceramics.

[0031] A method for detecting interface debonding in FRP-repaired hydraulic concrete structures includes:

[0032] S1. Connect the probe to the host, start the equipment, hold the probe and gently slide it across the FRP surface of the hydraulic concrete structure, and collect the sound signal simultaneously.

[0033] S2. Based on the location of obvious abnormal acoustic signals, use methods such as pressing and observation to determine and mark the specific detachment location, then cut off the connection between the probe and the host, and switch to the piezoelectric ceramic implantation mode;

[0034] S3. Insert the injection needle into the interface debonding zone and inject the curing agent, followed by injecting the piezoelectric ceramic and sealing the opening.

[0035] S4. Connect the piezoelectric ceramic wires to the main unit, check the normal operation of the inserted piezoelectric ceramic, and then encapsulate the piezoelectric ceramic wires.

[0036] S5. Regularly test multiple embedded piezoelectric ceramic connection hosts in a region to check for changes in interface debonding.

[0037] Preferably, in step S1, the device can move according to a pre-planned grid path, and the host synchronously records the position information and acoustic signal data to generate a preliminary interface bonding state distribution map.

[0038] Preferably, in step S2, for large areas, a probe can be used to quickly survey the area in host connection mode to mark all suspected points, and then the area can be uniformly converted to implantation mode for batch operation to improve work efficiency.

[0039] Preferably, in step S3, the order of injecting the curing agent and the piezoelectric ceramic can be adjusted as needed: a portion of the curing agent can be injected first, followed by the piezoelectric ceramic, and finally, the remaining curing agent can be injected to ensure complete coverage. Sealing is performed using a sealant similar in color to the FRP for surface dot sealing to maintain aesthetics and protect the implantation site.

[0040] Preferably, in step S4, during operation, the host computer can emit an electrical signal of a specific frequency to excite the piezoelectric ceramic, and the working status and coupling effect of the implanted sensor can be determined by analyzing the quality of its feedback signal. The encapsulation process for the wires includes combing and fixing them along the FRP surface and converging them into a pre-installed junction box.

[0041] Preferably, in step S5, the periodic detection can be set to a fixed cycle or triggered by external factors such as water level changes or seasonal temperature changes. During detection, the host can sequentially or synchronously stimulate multiple piezoelectric ceramic sensors, collect their response signals, and evaluate the evolution trend of the interfacial adhesion state by comparing with historical baseline data, thereby achieving an early warning function.

[0042] Furthermore, the detection of interface debonding in FRP-repaired hydraulic concrete structures includes not only the initial detection when the probe passes over the FRP, but also the key detection after the piezoelectric ceramic is inserted.

[0043] Furthermore, during the process of inserting the piezoelectric ceramic, the injected curing agent simultaneously repairs the debonding interface and fixes the piezoelectric ceramic; the inserted piezoelectric ceramic simultaneously detects interface debonding and serves as a skeleton support for the repair material.

[0044] The technical effects and advantages of this invention are as follows:

[0045] 1. This invention combines rapid acoustic screening with targeted implantation monitoring of piezoelectric ceramics, realizing an integrated detection process of "rapid initial inspection - precise marking - key detection". Compared with traditional single and discrete detection methods, this device has a high degree of integration, and can complete the entire process from large-area screening to sensor deployment in key areas in a single operation, greatly improving the systematic nature of the detection work and the convenience of subsequent key detection.

[0046] 2. The probe-integrated piezoelectric ceramic implantation mechanism proposed in this invention enables targeted marking and long-term sensing of potential debonding areas. After initially locating the debonding area through acoustic signal anomalies, a piezoelectric ceramic sensor can be directly implanted into the designated location using the same probe, a process that is precise and efficient. The implanted sensor can receive acoustic signals of the interface state stably and continuously over a long period, achieving fixed-point and continuous monitoring of potential malfunction points, overcoming the shortcomings of traditional methods that cannot perform location tracking.

[0047] 3. This invention utilizes the dual role of the curing agent during the implantation process to optimize the fixation and interface coupling effect of the monitoring sensor. The injected curing agent not only effectively fixes the piezoelectric ceramic sensor, ensuring its long-term tight coupling with the detection interface, but also forms a protective coating on the sensor, enhancing its durability and signal stability in harsh hydraulic environments, thereby ensuring the reliability and accuracy of long-term monitoring and detection data.

[0048] 4. This invention achieves a seamless transition from one-time detection to periodic, focused monitoring. The implanted piezoelectric ceramic sensor serves as a long-term monitoring point. By periodically connecting to the host computer to collect data, it can dynamically grasp the changing trends of the interface bonding state, enabling long-term evaluation and early warning of the FRP reinforcement effect, and providing intelligent technical support for the preventive maintenance of hydraulic concrete structures. Attached Figure Description

[0049] Figure 1 This is a schematic diagram illustrating the operation of the FRP repair interface debonding detection device of the present invention under the condition of FRP debonding caused by cracking of hydraulic concrete.

[0050] Figure 2 This is a schematic diagram of the probe structure of the FRP repair hydraulic concrete structure interface debonding detection device of the present invention.

[0051] Figure 3 This is a schematic diagram of the probe extrusion curing agent and extruded piezoelectric ceramic of the present invention.

[0052] Figure 4 This is a schematic cross-sectional view of the piezoelectric ceramic integrated core of the present invention.

[0053] Figure 5 This is a schematic diagram of the piezoelectric ceramic integrated core inserted into the piezoelectric ceramic structure of the present invention.

[0054] Figure 6 This is a schematic diagram of the external and cross-sectional structure of the piezoelectric ceramic of the present invention.

[0055] Figure 7 The first piezoelectric ceramic schematic diagram for the piezoelectric ceramic integrated core of the present invention is presented.

[0056] Figure 8This is a schematic diagram of the piezoelectric ceramic integrated core of the present invention being pulled back to the second piezoelectric ceramic.

[0057] Figure 9 This is a schematic diagram of the piezoelectric ceramic pusher tooth returning to center position according to the present invention.

[0058] Figure 10 A second piezoelectric ceramic schematic diagram is provided for the piezoelectric ceramic integrated core of the present invention.

[0059] Figure 11 This is a schematic diagram illustrating the operation of the FRP repair interface debonding detection device of the present invention under the condition of FRP debonding caused by bulging on the surface of hydraulic concrete.

[0060] Figure 12 This is a schematic diagram of the injection needle of the present invention penetrating the cracked gap of hydraulic concrete.

[0061] Figure 13 This is a schematic diagram of the curing agent of the present invention being injected into the cracked gap of hydraulic concrete along the injection needle orifice.

[0062] Figure 14 This is a schematic diagram of the piezoelectric ceramic of the present invention being injected along the injection needle into the cracked gap of hydraulic concrete.

[0063] Figure 15 This is a schematic diagram of the injection needle of the present invention penetrating the bulge on the surface of hydraulic concrete.

[0064] Figure 16 This is a schematic diagram showing the curing agent of the present invention being injected along the injection needle into the surface of hydraulic concrete, causing bulging.

[0065] Figure 17 This is a schematic diagram showing the piezoelectric ceramic of the present invention being injected along the injection needle orifice into the surface of hydraulic concrete, causing bulging.

[0066] Figure 18 This is a schematic diagram of the piezoelectric ceramic of the present invention placed in the crack gap of hydraulic concrete.

[0067] Figure 19 This is a schematic diagram of the piezoelectric ceramic of the present invention placed at the bulge on the surface of hydraulic concrete.

[0068] Figure 20 This is a schematic diagram illustrating the debonding evolution at the crack gap of hydraulic concrete detected by the placement of piezoelectric ceramics according to the present invention.

[0069] Figure 21 This is a schematic diagram illustrating the debonding evolution of bulges on the surface of hydraulic concrete detected by the placement of piezoelectric ceramics according to the present invention.

[0070] In the diagram: 1. Probe; 11. Piezoelectric ceramic wire; 12. Piezoelectric ceramic push valve; 13. Hardener push plate; 14. Piezoelectric ceramic integrated core; 141. Piezoelectric ceramic integrated core shell; 142. Rotating shaft; 143. Piezoelectric ceramic push tooth; 144. Spring; 145. Piezoelectric ceramic; 15. Hinged seal; 16. Injection needle port; 17. Hardener mixing chamber; 18. Hardener extrusion valve; 19. Hardener placement chamber; 110. Hardener push valve; 2. Main unit; 3. FRP; 4. Hydraulic concrete structure; 5. Interface debonding zone. Detailed Implementation

[0071] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0072] It should be noted that the piezoelectric ceramic involved in this invention is a common sensing and actuation material in the prior art, and its material properties, preparation method, and working principle are not the focus of this invention. The core innovation of this invention lies in creatively integrating piezoelectric ceramic as an implantable sensing unit into a set of integrated "detection-implantation-long-term monitoring" equipment and method for FRP-concrete interface debonding, and designing a matching mechanical implantation mechanism, signal transmission and processing system, and workflow.

[0073] It should be noted that the principle of collecting acoustic signals by tracing the FRP surface and identifying the debonding zone based on signal anomalies in this invention belongs to well-known acoustic detection and signal analysis techniques in non-destructive testing, and is not the focus of this invention. The core innovation of this invention lies in integrating the aforementioned rapid acoustic screening function with subsequent fixed-point sensor implantation and long-term monitoring functions into a single equipment system and operating method. Furthermore, it involves designing a dedicated probe structure and operating procedure to achieve coordinated "detection-implantation-focused detection" throughout the entire process, rather than relying on the general acoustic signal analysis technology itself.

[0074] First Embodiment

[0075] To address the issues in existing technologies where FRP interface debonding detection is disconnected from subsequent key monitoring and cannot provide long-term tracking of potential problems, this embodiment details the composition and working mode of an FRP-repaired hydraulic concrete structure interface debonding detection device. Figure 1-3 As shown.

[0076] (1) The device includes a probe (1) and a host (2). The probe (1) is a multi-functional integrated handheld device, which has a sound signal acquisition channel and a piezoelectric ceramic implantation channel arranged in parallel inside. The host (2) includes a signal acquisition module, a control module and a power supply module.

[0077] (2) In the initial detection mode, the operator holds the probe (1) and makes its end or the added solid part contact the FRP surface (3) and slide it across it at a uniform speed. At this time, the piezoelectric ceramic integrated core (14) works as an acoustic sensor and transmits the collected frictional sound signal to the host (2) through the piezoelectric ceramic wire (11). The host (2) analyzes the sound signal in real time. When the signal amplitude or frequency characteristics are abnormal, it prompts the location of the potential debonding area (5) through sound and light alarm, realizing large-area rapid screening of FRP debonding.

[0078] (3) After confirming the debonding location, the probe (1) can be operated directly on site. The same probe (1) can be used to inject curing agent into the designated debonding area (5) and implant piezoelectric ceramic (145), thereby establishing a permanent monitoring and detection point for the hidden danger point.

[0079] Second Embodiment

[0080] To address the problems of cumbersome procedures and poor sensor fixation and interface coupling in traditional methods, this embodiment details the collaborative mechanism of piezoelectric ceramic implantation and curing agent injection within the probe (1), such as... Figure 1-3 As shown.

[0081] (1) Prepare the implantation material. The piezoelectric ceramic (145) is a standard commercial chip sensor, which is pre-installed on the piezoelectric ceramic integrated core shell (141) of the piezoelectric ceramic integrated core (14). The curing agent is a two-component fast-curing epoxy resin, which is stored in the independent storage cylinder of the curing agent placement cavity (19).

[0082] (2) Align the injection port (16) of the probe (1) with and insert it into the marked interface debonding area (5). Operate the curing agent push valve (110) to drive the curing agent push plate (13) forward, push the two-component resin into the curing agent mixing chamber (17) for static mixing, and then inject it into the debonding gap from the injection port (16). Immediately afterwards, operate the piezoelectric ceramic push valve (12) to drive the piezoelectric ceramic push tooth (143) to rotate, and push the first piezoelectric ceramic (145) out of the shell (141).

[0083] (3) During the process of the piezoelectric ceramic (145) being pushed out, the piezoelectric ceramic integrated core (14) moves forward and its head pushes the hinge seal (15) to rotate, so that it just blocks the channel from the curing agent mixing chamber (17) to the injection needle (16), isolating the curing agent backflow channel, ensuring that the piezoelectric ceramic (145) is pushed out in a dry state and enters the debonding area filled with resin along the needle channel, avoiding the two from mixing and curing in advance inside the device, and ensuring the reliability of implantation.

[0084] Third Embodiment

[0085] To address the potential displacement or signal attenuation issues that may occur in implanted sensors during long-term monitoring, this embodiment details the dual fixing and protective effects of the curing agent on the piezoelectric ceramic, such as... Figure 18 , 19 As shown.

[0086] (1) After the piezoelectric ceramic (145) is implanted, it is completely immersed and encapsulated in the injected liquid epoxy resin. The resin is cured in situ within the debonding voids to form a robust polymer matrix.

[0087] (2) The cured resin firmly anchors the piezoelectric ceramic (145) in a specific position between the FRP (3) and the concrete (4), preventing it from shifting due to environmental vibration or water erosion. On the other hand, the resin matrix fills all the gaps between the sensor and the surrounding materials, ensuring the effective transmission of acoustic impedance and providing an excellent coupling medium for the piezoelectric ceramic (145) to capture interface acoustic signals in a long-term and stable manner.

[0088] (3) The cured resin layer that wraps the piezoelectric ceramic (145) can also effectively isolate the direct contact of corrosive media such as moisture and chloride ions, significantly improving the long-term durability and signal stability of the sensor in harsh hydraulic environments.

[0089] Fourth embodiment

[0090] To demonstrate the universal applicability of this method to debonding defects of different forms, this embodiment specifically implements two typical working conditions: "debonding caused by concrete cracking" and "debonding caused by concrete surface bulging".

[0091] (1) such as Figure 1 , 12 As shown in -14, 18, and 20, for concrete cracking conditions: During operation, the injection needle (16) is inserted along the surface of the FRP (3) and probes into the concrete crack gap below, i.e., the debonding zone (5). The injected curing agent is capillary-driven and permeates along the crack, and the subsequently implanted piezoelectric ceramic (145) is encapsulated by resin and positioned in the crack. Thereafter, the sensor specifically monitors the evolution of the interfacial bonding state in this crack region.

[0092] (2) such as Figure 11 , 15 As shown in -17, 19, and 21, for concrete surface bulging conditions: During operation, the injection needle (16) is inserted into the cavity from the center of the bulge. The injected curing agent fills the cavity, and the implanted piezoelectric ceramic (145) is then fixed to the center of the cavity. This sensor is subsequently used to monitor debonding changes at the interface of the bulging area.

[0093] Fifth embodiment

[0094] To address the issues of low efficiency in post-monitoring of large-area FRP-reinforced structures and difficulty in re-inspecting specific potential hazards, this embodiment details a regionalized key detection method based on an implanted piezoelectric ceramic network.

[0095] (1) After completing a preliminary survey of a large FRP reinforcement area, piezoelectric ceramics (145) were implanted at several high-risk debonding points as described in the above embodiment. The wires (11) leading out from each implantation point were collected into a central junction box.

[0096] (2) During subsequent periodic inspections, the inspectors do not need to perform large-area scans again. They only need to bring the main unit (2) to the site, open the junction box, and connect the wires of each implantation point sequentially or in parallel. The main unit (2) automatically sends excitation signals to each sensor and collects its response.

[0097] (3) The analysis software in the host (2) automatically compares the signal characteristics of each point collected this time, such as fundamental frequency impedance and resonant peak changes, with their respective historical baseline data. By analyzing the evolution trend of signal characteristics, it is possible to determine whether the bonding state of the interface at the corresponding point has deteriorated and its degree, thereby realizing intelligent, networked, long-term monitoring and accurate early warning of the health status of the interface in key areas of the structure.

[0098] Sixth Embodiment

[0099] To address the technical challenge of accurately and reliably implanting sensors in complex gaps at the FRP-concrete interface, this embodiment details the specific mechanical process by which the piezoelectric ceramic integrated core (14) sequentially ejects the piezoelectric ceramic (145), such as... Figure 4-10 As shown.

[0100] (1) Multiple disc-shaped piezoelectric ceramics (145) are coaxially mounted inside the piezoelectric ceramic integrated core housing (141). A rotating shaft (142) is fixed inside the housing (141). Two piezoelectric ceramic pusher teeth (143) are hinged to the shaft (142) through a central hole and can rotate freely around the shaft (142). The two ends of a tension spring (144) are respectively connected to the back of the two pusher teeth (143). Under the action of the spring (144), the tips of the two pusher teeth (143) are forced to open outward and simultaneously abut against the tail of the foremost piezoelectric ceramic (145), forming an initial stable state.

[0101] (2) When the operator presses the piezoelectric ceramic push valve (12), the valve stem moves forward, and the tip of the two push teeth (143) acts on the tail of the foremost piezoelectric ceramic (145). This thrust pushes the foremost piezoelectric ceramic (145) to smoothly push the outer shell (141) forward.

[0102] (3) When a single push stroke ends and the operator releases the piezoelectric ceramic push valve (12), the external thrust of the valve stem disappears. At this time, the spring (144) connected to the back of the push tooth (143) immediately contracts, pulling the tails of the two push teeth (143) back to both sides. This action causes the push tooth (143) to rotate in the opposite direction around the rotation axis (142), causing its tooth tip to change from an open state to an inward retraction and reset. During the reset process, the tooth tip moves inward, just sliding into and locking into the tail of the next piezoelectric ceramic (145), preparing for the push of the next sensor.

[0103] (4) This push-out process works in conjunction with the curing agent channel isolation mechanism described in the second embodiment. When the piezoelectric ceramic integrated core (14) moves forward as a whole due to the push-out action, its head synchronously drives the hinged seal (15) to close, ensuring the synchronization of the mechanical push-out action and the fluid channel control in terms of timing, and eliminating cross-contamination.

[0104] Seventh Embodiment

[0105] To address the issue that free water may exist inside the interface debonding zone (5) of hydraulic concrete structures in humid or seeping environments, thereby affecting the curing agent injection effect and the subsequent monitoring sensor coupling quality, this embodiment details the specific implementation plan of the equipment and method in dealing with the special working condition of water in bulges or cracks.

[0106] (1) After completing the preliminary acoustic detection and locating the debonding area (5) as described in the first embodiment, if water seeps out from the injection needle port (16) by observation or when the probe (1) is inserted, it is determined that water exists in the debonding area. In this case, the injection needle port (16) is kept in the inserted state as a temporary drainage hole. A micro negative pressure suction device can be connected to the needle port to try to suck out some free water to reduce the water volume in the cavity.

[0107] (2) For water-containing environments, the curing agent placement cavity (19) can be pre-filled with modified epoxy resin designed for wet interfaces, which can repel moisture and complete curing in the presence of a certain water film, or can be compatible with water and replace interface moisture to achieve underwater curing.

[0108] (3) Subsequently, the piezoelectric ceramic (145) pushing operation as described in the second and third embodiments is performed. The pushed-out piezoelectric ceramic (145), under the isolation protection of the hinge seal (15), passes through the needle channel where moisture may remain and is implanted into the area filled with curing agent.

[0109] Eighth embodiment

[0110] To address the problem that traditional passive acoustic detection is insensitive to early interface damage and lacks early warning capabilities, this embodiment details an active excitation detection method based on an implanted piezoelectric ceramic sensor network. This method transforms the implanted piezoelectric ceramic (145) from a passive signal receiver into an active excitation source with both excitation and reception functions, thereby enabling more precise diagnosis of the bonding state of the FRP-concrete interface.

[0111] (1) The implementation of this embodiment is based on the fact that, as described in the fifth embodiment, multiple piezoelectric ceramics (145) have been implanted and networked in a region. The hardware and software of the host (2) need to support active detection mode, its signal generation module can generate programmable specific waveform excitation signals, and its analysis module has advanced signal processing and comparative analysis capabilities.

[0112] (2) with Figure 20 , 21 Taking the monitoring area shown as an example, assume that three piezoelectric ceramics have been implanted in the area, labeled as sensors A, B, and C respectively. During regular key inspections, the operator connects the host (2) to the junction box of the area. The host (2) selects sensor A as the exciter and applies a high-voltage, short-duration electrical pulse to it. Sensor A generates high-frequency micromechanical vibration due to the inverse piezoelectric effect, and this vibration propagates in the form of stress waves in the FRP (3) and through the interfacial bonding layer into the concrete (4).

[0113] Meanwhile, the host (2) sets sensors B and C to receiver mode and synchronously acquires the signals of the stress wave emitted by sensor A after it has traveled through different paths. Among them, sensor B may be located near the same debonding zone (5) as A, while sensor C may be located in a relatively intact area. The algorithm built into the host (2) analyzes the received signals and extracts key parameters such as wave velocity, signal attenuation, and energy.

[0114] Ninth Embodiment

[0115] To address the problem that the external lead wire (11) of the implanted piezoelectric ceramic sensor is exposed to harsh hydraulic environments for a long time and is susceptible to water flow erosion, aging and mechanical damage, which leads to the failure of the monitoring network, this embodiment details a system wire integration and durability assurance scheme.

[0116] (1) After the piezoelectric ceramic (145) implantation and surface sealing as described in the third embodiment are completed, the lead wire (11) should be processed immediately. The lead wire (11) should be laid flat against the FRP surface (3) for a distance and covered with epoxy sealant.

[0117] (2) When the wires (11) of multiple sensors in an area are laid to a predetermined convergence point in the above manner, a junction box is formed by excavating or pre-burying an embedded monitoring socket box. The box is made of corrosion-resistant alloy or engineering plastic, and all wires (11) are introduced into the box through the waterproof gland at the bottom of the box.

Claims

1. A device for detecting interface debonding in FRP-repaired hydraulic concrete structures, characterized in that, The device includes a probe (1) and a host (2). The probe (1) generates an acoustic signal by tracing across the surface of the FRP (3). The abnormal acoustic signal caused by the interface debonding zone (5) generated by the hydraulic concrete structure (4) under the FRP (3) is received and identified by the host (2).

2. The FRP repair hydraulic concrete structure interface debonding detection device according to claim 1, characterized in that, The probe (1) includes a piezoelectric ceramic wire (11), a piezoelectric ceramic push valve (12), a curing agent push plate (13), a piezoelectric ceramic integrated core (14), a hinge seal (15), an injection needle port (16), a curing agent mixing chamber (17), a curing agent extrusion valve (18), a curing agent placement chamber (19), and a curing agent push valve (110). Among them, the piezoelectric ceramic wire (11) is connected to the tail end of the piezoelectric ceramic integrated core (14) to transmit the surface acoustic signal of FRP (3) to the host (2); the piezoelectric ceramic push valve (12) is connected to the piezoelectric ceramic integrated core (14) to squeeze the piezoelectric ceramic (145) on the piezoelectric ceramic integrated core (14) into the interface debonding zone (5); the curing agent push plate (13) is set in the curing agent placement cavity (19), and its top end is connected to the curing agent push valve (110) to squeeze the curing agent out of the curing agent extrusion valve. The door (18) is inserted into the curing agent mixing chamber (17), and after mixing, it is extruded from the injection needle port (16) and squeezed into the interface debonding zone (5); the hinge seal (15) is located at the head of the piezoelectric ceramic integrated core (14). During the extrusion of the piezoelectric ceramic (145), the hinge seal (15) can rotate and seal the channel from the curing agent mixing chamber (17) to the injection needle port (16) to isolate the curing agent during the extrusion of the piezoelectric ceramic (145) and prevent the curing agent from mixing with the piezoelectric ceramic (145) too early.

3. The FRP repair hydraulic concrete structure interface debonding detection device according to claim 1, characterized in that, The piezoelectric ceramic integrated core (14) also includes a piezoelectric ceramic integrated core shell (141), a rotating shaft (142), piezoelectric ceramic push teeth (143), a spring (144), and piezoelectric ceramic (145). The piezoelectric ceramic integrated core housing (141) has a rotating shaft (142) fixed inside, which is used to fix the top of the piezoelectric ceramic push tooth (143) so that the piezoelectric ceramic push tooth (143) rotates around the rotating shaft (142); the spring (144) connects the back side of the two piezoelectric ceramic push teeth (143) and is used to reset the piezoelectric ceramic push tooth (143); the piezoelectric ceramic integrated core housing (141) is fitted with multiple piezoelectric ceramics (145). After the piezoelectric ceramic push tooth (143) pushes a piezoelectric ceramic (145), it is reset and then pushes the subsequent piezoelectric ceramic (145).

4. A method for detecting interface debonding in FRP-repaired hydraulic concrete structures, comprising: S1. Connect the probe (1) to the host (2). After starting the device, hold the probe (1) and gently slide it across the FRP (3) on the surface of the hydraulic concrete structure (4) while collecting the acoustic signal simultaneously. S2. Based on the location of the obviously abnormal acoustic signal, the specific detachment location is determined and marked by pressing, observation and other methods. Then the connection between the probe (1) and the host (2) is disconnected, and the piezoelectric ceramic (145) implantation mode is switched. S3. Insert the injection needle (16) into the interface debonding area (5) and inject the curing agent, then inject the piezoelectric ceramic (145) and seal it. S4. Connect the piezoelectric ceramic wire (11) to the host (2), check the normal operation of the inserted piezoelectric ceramic (145), and then encapsulate the piezoelectric ceramic wire (11). S5. Periodically test the connection of multiple inserted piezoelectric ceramics (145) to the host (2) in a certain area to check the changes in interface debonding.

5. The method for detecting interface debonding in FRP-repaired hydraulic concrete structures according to claim 4, characterized in that, The detection of interface debonding of FRP repaired hydraulic concrete structure is not only the initial detection when the probe (1) passes through the FRP (3), but also the key detection after the piezoelectric ceramic (145) is placed.

6. The method for detecting interface debonding in FRP-repaired hydraulic concrete structures according to claim 4, characterized in that, During the process of inserting the piezoelectric ceramic (145), the injected curing agent simultaneously repairs the debonding interface and fixes the piezoelectric ceramic (145); the inserted piezoelectric ceramic (145) simultaneously detects interface debonding and serves as a skeleton support for the repair material.

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