Structural damage detection method for carbon fiber reinforced resin-based composite material

Abstract

The invention discloses a structural damage detection method for a carbon fiber reinforced resin-based composite material, and relates to the technical field of nondestructive testing, and the method comprises the following steps: acquiring resonant frequency data in real time through a micro-cantilever array, and irradiating a composite sensitive coating on the surface of the micro-cantilever array by using a plasmon laser beam to excite plasmon polariton resonance; the position of the micro-cantilever array with the resonance frequency data exceeding a reference deviation threshold value and the frequency shift amount of the plasmon polariton resonance exceeding a preset background noise fluctuation range is judged as a suspected damage position; and triggering electrochemical deposition through the coordinates of the suspected damaged position, and applying constant negative voltage to the surface of the suspected damaged position to generate metal mark stripes. By comparing the resonance frequency data with the reference resonance frequency data in the initial state, the position where the frequency deviation exceeds the preset threshold value is identified, and accurate capture of the mechanical response abnormity is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of nondestructive testing, in particular to a method for detecting structural damage of a carbon fiber reinforced resin-based composite material. Background Art

[0002] Carbon fiber reinforced resin-based composites are widely used in aerospace, marine engineering, and high-end transportation equipment due to their high specific strength, high specific modulus, and excellent fatigue performance. However, such composites are prone to irreversible damage such as microcracks, interface delamination, or fiber breakage in stress concentration areas under complex service environments. Therefore, how to achieve highly sensitive and visual detection of internal or surface structural damage in composite materials has become an important research direction for composite structural health monitoring. In recent years, mechanical response monitoring based on micro-nano sensors and characterization methods based on optical methods have gradually attracted attention. Deploying sensitive units on the surface of the material and combining optical or electrical excitation methods to obtain damage signals has become an important path to achieve micro-damage identification of composite materials.

[0003] While existing technologies for composite material damage detection can generally identify macroscopic defects, they still struggle with early detection and localization of micro-damage. This is particularly true in areas of stress concentration, where it is difficult to simultaneously achieve high-sensitivity mechanical and optical signal coupling enhancement. This issue often makes the damage signal susceptible to noise interference, hindering accurate calibration of the damage location. Existing structural damage detection methods typically compensate by increasing sensor density or implementing complex signal filtering algorithms. However, these approaches can weaken micro-damage signals and exhibit significant noise interference. Summary of the Invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a structural damage detection method for carbon fiber reinforced resin-based composite materials to solve the problem of difficulty in simultaneously obtaining coupling enhancement of high-sensitivity mechanical signals and optical signals in stress concentration areas.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for detecting structural damage of a carbon fiber reinforced resin-based composite material, which comprises: A micro-cantilever array is deployed on the surface of the stress concentration position of the carbon fiber reinforced resin-based composite material; the surface of the micro-cantilever array is covered with a composite sensitive coating; Resonance frequency data is collected in real time through a microcantilever array. A plasmon laser beam is simultaneously irradiated on the composite sensitive coating on the surface of the microcantilever array to stimulate plasmon polariton resonance. Positions on the microcantilever array where the resonance frequency data exceeds a baseline offset threshold and the frequency shift of the plasmon polariton resonance exceeds a preset background noise fluctuation range are identified as suspected damage locations. Electrochemical deposition is triggered by the coordinates of the suspected damage location, and a constant negative voltage is applied to the surface of the suspected damage location using the exposed carbon fiber of the carbon fiber reinforced resin-based composite material as a reference electrode to generate metal marking stripes; The spatial distribution image of the metal mark stripes is scanned by a portable optical microscope, and the crystal structure diffraction peak intensity data of the metal mark stripes is scanned by a portable X-ray diffractometer. A structural damage verification report is generated based on the distribution morphology and crystal structure diffraction peak intensity data.

[0007] As a preferred solution of the structural damage detection method of the carbon fiber reinforced resin-based composite material of the present invention, wherein: the micro-cantilever beam array is deployed on the surface of the stress concentration position of the carbon fiber reinforced resin-based composite material, specifically as follows: Performing oxygen plasma treatment on the edge of the bolt hole and the curved surface transition area of ​​the carbon fiber reinforced resin matrix composite material to form a pre-treated area of ​​the carbon fiber reinforced resin matrix composite material; Nano-silver conductive adhesive is used to bond silicon-based micro-cantilever beams in the pretreatment area of ​​the carbon fiber reinforced resin-based composite material to form a rectangularly arranged micro-cantilever beam array.

[0008] As a preferred solution of the structural damage detection method of the carbon fiber reinforced resin-based composite material of the present invention, wherein: the real-time acquisition of resonance frequency data by the micro-cantilever array is as follows: Establishing electrical connection between the microcantilever array and the resonance frequency acquisition instrument; An alternating electrostatic excitation is applied to the microcantilever array through a resonance frequency acquisition instrument, the response frequency of the microcantilever array is scanned, and the resonance frequency value displayed by the resonance frequency acquisition instrument is read as the resonance frequency data of the microcantilever array.

[0009] As a preferred embodiment of the structural damage detection method for carbon fiber reinforced resin-based composite materials of the present invention, the composite sensitive coating on the surface of the microcantilever array is irradiated with a plasma laser beam to excite plasmon polaritons, specifically as follows: One end of the optical fiber is connected to the output port of the plasma laser emitting device, and the other end is led to the microcantilever array; Adjust the position and angle of the optical fiber outlet to align it with the composite sensitive coating on the surface of the micro-cantilever array, and keep the emission direction perpendicular to the surface of the composite sensitive coating; Starting the plasma laser emitting device, which outputs a plasma laser beam after being preheated and stabilized; The plasmon laser beam is transmitted to the composite sensitive coating on the surface of the microcantilever array through an optical fiber that is connected and aligned with the composite sensitive coating, thereby exciting plasmon polaritons resonance.

[0010] As a preferred embodiment of the structural damage detection method for carbon fiber reinforced resin-based composite materials of the present invention, the determination of whether the resonance frequency data exceeds the reference offset threshold is as follows: Obtain the initial resonance frequency value of the micro-cantilever beam array under stress-free loading as the reference resonance frequency data; Comparing the real-time collected resonance frequency data of each position of the micro-cantilever array with the reference resonance frequency data of the corresponding position to determine the resonance frequency offset of each position of the micro-cantilever array; When the resonance frequency offset of a certain position of the micro-cantilever array is greater than a preset reference offset threshold, the plasmon polariton resonance frequency shift verification of the micro-cantilever array position where the resonance frequency offset exceeds the reference offset threshold is started.

[0011] As a preferred solution of the structural damage detection method for carbon fiber reinforced resin-based composite materials of the present invention, the reference offset threshold is determined based on the initial resonance frequency distribution of the micro-cantilever beam array in a stress-free state.

[0012] As a preferred embodiment of the structural damage detection method for carbon fiber reinforced resin-based composite materials of the present invention, the position of the micro-cantilever array at which the frequency shift of the plasmon polariton resonance exceeds the preset background noise fluctuation range is as follows: Under the condition of plasmon polariton resonance excitation, the optical near-field enhanced response spectrum of the composite sensitive coating is monitored to obtain the real-time resonance frequency of the plasmon polariton resonance; The real-time resonance frequency of the plasmon polariton resonance is compared with the initial resonance frequency value under the stress-free loading state to determine the frequency shift of the plasmon polariton resonance; When the frequency shift of the plasmon polariton resonance is greater than a maximum value of a preset background noise fluctuation range, it is determined that the frequency shift of the plasmon polariton resonance exceeds the background noise fluctuation range.

[0013] As a preferred solution of the structural damage detection method for carbon fiber reinforced resin-based composite materials described in the present invention, the background noise fluctuation range is determined based on the plasmon polariton resonance frequency fluctuation characteristics of the optical near-field enhanced response spectrum of the composite sensitive coating under a stress-free loading state.

[0014] As a preferred embodiment of the structural damage detection method for carbon fiber reinforced resin-based composite materials of the present invention, the coordinates of the suspected damage location are used to trigger electrochemical deposition, and a constant negative voltage is applied to the surface of the suspected damage location using the exposed carbon fiber of the carbon fiber reinforced resin-based composite material as a reference electrode to generate metal marking stripes, as follows: According to the coordinates of the suspected damage location, the electrochemical deposition probe is driven to move to the top of the suspected damage location; Connecting the exposed carbon fiber of the carbon fiber reinforced resin matrix composite material to the reference electrode interface of the electrochemical controller as a reference electrode for electrochemical deposition; Activating the electrolyte release component of the electrochemical deposition probe to release electrolyte containing metal ions onto the surface of the suspected damage location, thereby forming a local electrochemical reaction area; In the local electrochemical reaction area, a constant negative voltage is applied between the electrochemical deposition probe and the exposed carbon fibers of the carbon fiber reinforced resin matrix composite material through an electrochemical controller; Under a constant negative voltage, metal ions are reduced and deposited on the surface of suspected damage locations, forming metal deposition spots; A constant negative voltage is continuously applied until the metal deposition spot grows to a size that can be identified by optical means, outputting a metal marking stripe.

[0015] As a preferred embodiment of the structural damage detection method for carbon fiber reinforced resin-based composite materials of the present invention, the spatial distribution image of the metal marking stripes is scanned by a portable optical microscope, the crystal structure diffraction peak intensity data of the metal marking stripes is scanned by a portable X-ray diffractometer, and a structural damage verification report is generated based on the distribution morphology and crystal structure diffraction peak intensity data, as follows: A portable optical microscope is aligned with the location area of ​​the metal marking stripes on the surface of the carbon fiber reinforced resin matrix composite material, the focal length and light source of the portable optical microscope are adjusted, and the portable optical microscope is driven to scan the area covered by the metal marking stripes along a grid scanning path, and a spatial distribution image of the metal marking stripes is recorded; Start the portable X-ray diffractometer to scan the metal marking stripes and obtain the crystal structure diffraction pattern; Extract the crystal structure diffraction peak intensity data of the metal marking stripes from the diffraction pattern.

[0016] The beneficial effects of the present invention are as follows: by comparing the resonant frequency data with the reference resonant frequency data in the initial state, the position where the frequency offset exceeds the preset threshold is identified, thereby achieving accurate capture of mechanical response anomalies. At the same time, a plasmon laser beam is applied to the frequency offset position to stimulate the plasmon polariton resonance on the surface of the composite sensitive coating, and the frequency shift of its optical near-field enhanced response spectrum is monitored to determine whether it exceeds the background noise fluctuation range; this dual judgment mechanism uses mechanical vibration and optical near-field enhancement dual signal cross-verification to avoid misjudgment caused by environmental interference on a single signal, significantly improving the reliability and sensitivity of damage identification; the micro-cantilever beam array and the composite sensitive coating work together to effectively sense the tiny deformation caused by microcracks and changes in the surface chemical environment, thereby achieving high-precision positioning and confirmation of early damage to carbon fiber reinforced resin-based composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 Flowchart of the structural damage detection method for carbon fiber reinforced resin matrix composite materials.

[0019] Figure 2 Flowchart for deploying a microcantilever array.

[0020] Figure 3 Flowchart for determining suspected damage locations.

[0021] Figure 4 Flowchart generated for the Structural Damage Verification Report. DETAILED DESCRIPTION

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0025] Reference Figures 1 to 4 , is an embodiment of the present invention, which provides a method for detecting structural damage of a carbon fiber reinforced resin-based composite material, comprising the following steps: S1. A micro-cantilever array is deployed on the surface of a stress concentration location of a carbon fiber reinforced resin-based composite material; and the surface of the micro-cantilever array is covered with a composite sensitive coating.

[0026] Performing oxygen plasma treatment on the edge of the bolt hole and the curved surface transition area of ​​the carbon fiber reinforced resin matrix composite material to form a pre-treated area of ​​the carbon fiber reinforced resin matrix composite material; Specifically, the process includes placing the edge of the bolt hole and the curved surface transition area of ​​the carbon fiber reinforced resin-based composite material in a working chamber of an oxygen plasma treatment device; adjusting the operating parameters of the oxygen plasma treatment device to ensure a stable oxygen flow rate and maintain a vacuum environment in the working chamber; starting the oxygen plasma treatment device to generate oxygen plasma, and allowing the oxygen plasma to contact the edge of the bolt hole and the surface of the curved surface transition area of ​​the carbon fiber reinforced resin-based composite material; maintaining the oxygen plasma treatment device in operation for a specified time, such as 10 minutes, so that the oxygen plasma removes surface contaminants and activates the edge of the bolt hole and the surface of the curved surface transition area of ​​the carbon fiber reinforced resin-based composite material, thereby forming a pre-treated area of ​​the carbon fiber reinforced resin-based composite material with increased surface roughness and enhanced chemical activity; Nano-silver conductive adhesive is used to bond silicon-based micro-cantilever beams to the pre-treated area of ​​the carbon fiber reinforced resin-based composite material to form a rectangularly arranged micro-cantilever beam array; A composite sensitive coating solution is prepared by mixing a polydimethylsiloxane precursor and platinum nanoparticles in a certain mass ratio, and the solution is coated on the surface of the microcantilever array by spin coating. Annealing the coated surface of the micro-cantilever array to form a composite sensitive coating; Specifically, the process involves placing a microcantilever array containing a composite sensitive coating solution in an annealing furnace; adjusting the temperature of the annealing furnace to a specified value, such as 150 degrees Celsius, and ensuring that the atmosphere in the annealing furnace is an inert gas environment, such as nitrogen, to prevent oxidation; starting the annealing furnace to continuously heat the composite sensitive coating solution on the surface of the microcantilever array at a specified temperature, for example, for 30 minutes, to promote the curing of the polydimethylsiloxane precursor and enhance the bonding between the platinum nanoparticles and the polydimethylsiloxane matrix; after heating is completed, closing the annealing furnace and allowing the microcantilever array to cool naturally to room temperature to form a uniform and stable composite sensitive coating.

[0027] S2. Real-time resonant frequency data is collected through the microcantilever array. Simultaneously, a plasmon laser beam is used to illuminate the composite sensitive coating on the surface of the microcantilever array to stimulate plasmon-polariton resonance. The microcantilever array position where the resonant frequency data exceeds the reference offset threshold and the frequency shift of the plasmon-polariton resonance exceeds the preset background noise fluctuation range is determined as a suspected damage position.

[0028] Establishing electrical connection between the microcantilever array and the resonance frequency acquisition instrument; Applying alternating electrostatic excitation to the micro-cantilever array through a resonance frequency acquisition instrument, scanning the response frequency of the micro-cantilever array, and reading the resonance frequency value displayed by the resonance frequency acquisition instrument as the resonance frequency data of the micro-cantilever array; Specifically, the process includes: connecting a resonance frequency acquisition instrument to the electrode interface of the microcantilever array via a wire to ensure stable electrical signal transmission; starting the resonance frequency acquisition instrument and setting the frequency range of the alternating electrostatic excitation, for example, from 1 kHz to 100 kHz; applying alternating electrostatic excitation to the microcantilever array to cause each silicon-based microcantilever unit to vibrate; using the resonance frequency acquisition instrument to scan the vibration response of the microcantilever array and recording the frequency value corresponding to the maximum amplitude of each silicon-based microcantilever unit under excitation; and reading the frequency value displayed by the resonance frequency acquisition instrument as the resonance frequency data of the microcantilever array. One end of the optical fiber is connected to the output port of the plasma laser emitting device, and the other end is led to the microcantilever array; Adjust the position and angle of the optical fiber outlet to align it with the composite sensitive coating on the surface of the micro-cantilever array, and keep the emission direction perpendicular to the surface of the composite sensitive coating; Starting the plasma laser emitting device, which outputs a plasma laser beam after being preheated and stabilized; The plasmon laser beam is transmitted to the composite sensitive coating on the surface of the microcantilever array through an optical fiber that is connected and adjusted to align with the composite sensitive coating to excite plasmon polariton resonance; Specifically, the plasmon laser beam is transmitted to the composite sensitive coating on the surface of the microcantilever array through an optical fiber, so that the plasmon laser beam is irradiated on the composite sensitive coating composed of polydimethylsiloxane and platinum nanoparticles; the plasmon laser beam interacts with the platinum nanoparticles in the composite sensitive coating, inducing local electromagnetic field enhancement, and exciting the surface of the composite sensitive coating to produce plasmon-polariton resonance, providing an optical near-field enhanced response spectrum for subsequent monitoring of the frequency shift of the plasmon-polariton resonance.

[0029] Obtain the initial resonance frequency value of the micro-cantilever beam array under stress-free loading as the reference resonance frequency data; Specifically, the method includes: fixing the carbon fiber reinforced resin-based composite material in a stress-free loading environment to ensure that the microcantilever array is not disturbed by external mechanical forces; connecting a resonance frequency acquisition instrument to the electrode interface of the microcantilever array to confirm that the electrical signal path is intact; activating the resonance frequency acquisition instrument, configuring the frequency range of alternating electrostatic excitation, for example, 1 kHz to 100 kHz, to drive the center of each silicon-based microcantilever to vibrate; using the resonance frequency acquisition instrument to detect the vibration behavior of the microcantilever array, and recording the frequency value corresponding to the center of each silicon-based microcantilever at the maximum amplitude; extracting the frequency value displayed by the resonance frequency acquisition instrument as the baseline resonance frequency data of the microcantilever array; Comparing the real-time collected resonance frequency data of each position of the micro-cantilever array with the reference resonance frequency data of the corresponding position to determine the resonance frequency offset of each position of the micro-cantilever array; Specifically, the real-time resonance frequency data and the reference resonance frequency data of the micro-cantilever array are input into the frequency comparison component of the resonance frequency acquisition instrument. The frequency comparison component compares the real-time frequency value of each silicon-based micro-cantilever center with the corresponding reference frequency value one by one, and records the difference between the two. All comparison results are arranged in order of position to form a resonance frequency offset value list containing the difference information of each position. The resonance frequency offset value of each position is extracted from the resonance frequency offset value list as the resonance frequency offset value of each silicon-based micro-cantilever center of the micro-cantilever array. When the resonant frequency offset of a certain position of the micro-cantilever array is greater than a preset reference offset threshold, starting to check the plasmon polariton resonance frequency shift at the position of the micro-cantilever array where the resonant frequency offset exceeds the reference offset threshold; Specifically, the resonance frequency offset of each silicon-based microcantilever center of the microcantilever array is compared with the preset reference offset threshold one by one; when the resonance frequency offset of a silicon-based microcantilever center of the microcantilever array exceeds the preset reference offset threshold, the plasmon laser emission device is activated; the plasmon laser beam is transmitted to the composite sensitive coating surface of the silicon-based microcantilever center of the microcantilever array via an optical fiber; the position and angle of the optical fiber outlet are adjusted to ensure that the plasmon laser beam vertically irradiates the composite sensitive coating surface to stimulate plasmon polariton resonance; the optical near-field enhanced response spectrometer is started to collect the resonance frequency of the silicon-based microcantilever center of the microcantilever array The optical near-field enhanced response spectrum of the center of the base microcantilever under plasmon-polariton resonance excitation is obtained; the real-time frequency value of the plasmon-polariton resonance is extracted from the optical near-field enhanced response spectrum; the real-time frequency value of the plasmon-polariton resonance is compared one by one with the initial plasmon-polariton resonance frequency value under a stress-free loading state, and the frequency difference between the two is recorded; the frequency difference is stored as a basis for verifying the frequency shift of the plasmon-polariton resonance; wherein a preset reference offset threshold is determined based on the initial resonance frequency distribution of the microcantilever array under a stress-free state, for example, set to 5 Hz, for detecting frequency offset caused by microcracks; Under the condition of plasmon polariton resonance excitation, the optical near-field enhanced response spectrum of the composite sensitive coating is monitored to obtain the real-time resonance frequency of the plasmon polariton resonance; Specifically, under the condition of plasmon polariton resonance excitation, an optical near-field enhanced response spectrometer is started; a probe of the optical near-field enhanced response spectrometer is aligned with the surface of the composite sensitive coating at the center of the silicon-based microcantilever corresponding to the microcantilever array; the position and angle of the probe are adjusted to ensure that the probe and the surface of the composite sensitive coating maintain a distance and are vertically aligned; optical near-field enhanced response spectrum data of the composite sensitive coating at the center of the silicon-based microcantilever corresponding to the microcantilever array is collected by the optical near-field enhanced response spectrometer; the real-time resonance frequency value of the plasmon polariton resonance is extracted from the optical near-field enhanced response spectrum data; the real-time resonance frequency value of the plasmon polariton resonance is recorded as the real-time resonance frequency monitoring result of the plasmon polariton resonance; The real-time resonance frequency of the plasmon polariton resonance is compared with the initial resonance frequency value under the stress-free loading state to determine the frequency shift of the plasmon polariton resonance; Specifically, the real-time plasmon polariton resonance frequency value of the composite sensitive coating at the center of each silicon-based microcantilever in the microcantilever array collected by the optical near-field enhanced response spectrometer under the condition of plasmon polariton resonance excitation is transmitted to the frequency comparison component; the initial plasmon polariton resonance frequency value of the corresponding position is extracted from the stored initial plasmon polariton resonance frequency value of the center of each silicon-based microcantilever in the microcantilever array under the stress-free loading state; the plasmon polariton resonance frequency value of the center of each silicon-based microcantilever in the microcantilever array is compared one by one by the frequency comparison component. The real-time resonance frequency value of the polariton resonance and the initial plasmon polariton resonance frequency value at the corresponding position; the frequency difference between the real-time resonance frequency value of the plasmon polariton resonance at the center of each silicon-based microcantilever in the microcantilever array and the initial plasmon polariton resonance frequency value is recorded; the frequency difference is recorded as the frequency shift of the plasmon polariton resonance; for example, if the real-time resonance frequency value of the plasmon polariton resonance is 1000 THz and the initial plasmon polariton resonance frequency value is 995 THz, then the frequency shift of the plasmon polariton resonance is 5 THz; When the frequency shift of the plasmon polariton resonance is greater than the maximum value of the preset background noise fluctuation range, it is confirmed that the frequency shift of the plasmon polariton resonance exceeds the background noise fluctuation range; wherein the preset background noise fluctuation range is determined based on the plasmon polariton resonance frequency fluctuation characteristics of the optical near-field enhanced response spectrum of the composite sensitive coating under a stress-free loading state, for example, a value range of 0.1-1 THz, so as to distinguish the frequency shift caused by microcracks from environmental noise; The position of the micro-cantilever array where the resonance frequency offset exceeds the reference offset threshold and the frequency shift of the plasmon polariton resonance exceeds the preset background noise fluctuation range is determined as a suspected damage position.

[0030] It should be noted that this step realizes high-precision online monitoring of structural damage of carbon fiber reinforced resin-based composite materials, improves detection sensitivity, real-time performance and accuracy, and reduces the misjudgment rate; compared with traditional ultrasonic or thermal imaging detection, the innovation of this step lies in the integration of mechanical vibration response and optical near-field enhancement, overcoming the limitations of low microcrack resolution and non-real-time monitoring, improving efficiency and simplifying operation, and fully reflecting the application value of mechanical sensors. The mechanical sensor is the micro-cantilever beam array in the step.

[0031] S3. Electrochemical deposition is triggered by the coordinates of the suspected damage location. The exposed carbon fiber of the carbon fiber reinforced resin-based composite material is used as a reference electrode. A constant negative voltage is applied to the surface of the suspected damage location to generate metal marking stripes.

[0032] Spatially aligning the coordinate system of the electrochemical deposition positioning assembly with the coordinate system of the microcantilever array positioning assembly ensures that the coordinate information of the suspected damage location can be directly accessed by the electrochemical deposition process. The electrochemical deposition positioning assembly is a device used to precisely align coordinates and move the probe to a specific surface location for electrochemical deposition. It is formed based on microcantilever array coordinate positioning technology and precision mechanical control technology. Specifically, the coordinate system data of the micro-cantilever array positioning assembly is transmitted to the electrochemical deposition positioning assembly; the coordinate system data of the micro-cantilever array positioning assembly is read by the coordinate calibration instrument built into the electrochemical deposition positioning assembly; the coordinate calibration instrument of the electrochemical deposition positioning assembly is adjusted to achieve precise alignment of the coordinate system of the electrochemical deposition positioning assembly with the coordinate system of the micro-cantilever array positioning assembly in three-dimensional space; the coordinate point of the center of each silicon-based micro-cantilever in the micro-cantilever array is verified to be consistent with the coordinate point of the electrochemical deposition positioning assembly; the aligned coordinate system data is stored to ensure that the coordinate information of the suspected damage location is directly transmitted to the electrochemical deposition positioning assembly for subsequent electrochemical deposition probe positioning; Based on the coordinates of the suspected damage location, the electrochemical deposition probe is driven to move directly above the suspected damage location. The electrochemical deposition probe is a precision device used to release electrolyte and apply voltage to the surface of the suspected damage location to induce metal ion deposition. The exposed carbon fibers of the carbon fiber reinforced resin-based composite material are connected to the reference electrode interface of the electrochemical controller as a reference electrode for electrochemical deposition; wherein the electrochemical controller is an existing device used to adjust and maintain the voltage or current stability during the electrochemical deposition process.

[0033] Activating the electrolyte release component of the electrochemical deposition probe to release electrolyte containing metal ions onto the surface of the suspected damage location, thereby forming a local electrochemical reaction area; Specifically, the process includes: transferring the electrolyte containing metal ions to the electrolyte release nozzle through the electrolyte storage chamber of the electrochemical deposition probe; adjusting the position of the electrolyte release nozzle of the electrochemical deposition probe to ensure that the nozzle is aligned with the suspected location of damage on the surface of the carbon fiber reinforced resin-based composite material; controlling the electrolyte release nozzle of the electrochemical deposition probe to open and release the electrolyte containing metal ions to the suspected location of damage on the surface of the carbon fiber reinforced resin-based composite material; continuously releasing the electrolyte containing metal ions until a local electrochemical reaction area covering the suspected location of damage on the surface of the carbon fiber reinforced resin-based composite material is formed; closing the electrolyte release nozzle of the electrochemical deposition probe to stop the electrolyte release and ensure the stable formation of the local electrochemical reaction area; In the local electrochemical reaction area, a constant negative voltage is applied between the electrochemical deposition probe and the exposed carbon fibers of the carbon fiber reinforced resin matrix composite material through an electrochemical controller to maintain the voltage constant; Specifically, the steps include: starting the electrochemical controller to initialize the electrical signal path between the electrochemical deposition probe and the exposed carbon fiber near the suspected location of surface damage of the carbon fiber reinforced resin-based composite material; setting a constant negative voltage value through the electrochemical controller, for example, a value of -0.2V; placing the electrode end of the electrochemical deposition probe within the local electrochemical reaction area at the suspected location of surface damage of the carbon fiber reinforced resin-based composite material; applying a constant negative voltage to the electrode end of the electrochemical deposition probe through the electrochemical controller, and using the exposed carbon fiber near the suspected location of surface damage of the carbon fiber reinforced resin-based composite material as a reference electrode; continuously monitoring the voltage output state of the electrochemical controller to ensure that the constant negative voltage remains stable within the local electrochemical reaction area; and maintaining the constant negative voltage applied by the electrochemical controller until the subsequent metal deposition process is completed. Under a constant negative voltage, metal ions are reduced and deposited on the surface of suspected damage locations, forming metal deposition spots; Specifically, the electrode end of the electrochemical deposition probe is used to induce the reduction of metal ions in the electrolyte containing metal ions in the local electrochemical reaction area; the reduced metal ions are deposited in microcracks or pores at suspected locations of damage on the surface of the carbon fiber reinforced resin-based composite material; a constant negative voltage is continuously applied by the electrochemical controller to promote the formation of metal deposition spots of metal ions at suspected locations of damage on the surface of the carbon fiber reinforced resin-based composite material; the formation of the metal deposition spots is observed to ensure that the metal deposition spots are stably generated in the local electrochemical reaction area; A constant negative voltage is continuously applied until the metal deposition spot grows to a size that can be identified by optical means, and a metal marking stripe is output; wherein the size that can be identified by optical means refers to a size in which the width of the metal deposition spot reaches, for example, 20 microns, which can be clearly imaged by a portable optical microscope.

[0034] S4. Scan the spatial distribution image of the metal marking stripes with a portable optical microscope, scan the crystal structure diffraction peak intensity data of the metal marking stripes with a portable X-ray diffractometer, and generate a structural damage verification report based on the distribution morphology and crystal structure diffraction peak intensity data.

[0035] A portable optical microscope is aligned with the location of the metal marking stripes on the surface of the carbon fiber reinforced resin matrix composite material, and the focal length and light source of the portable optical microscope are adjusted to clearly image the metal marking stripes; wherein, the portable optical microscope is a lightweight imaging device for magnifying and observing the surface morphology of tiny objects, which is an existing device; Drive the portable optical microscope to scan the area covered by the metal mark stripes along the grid scanning path, and record the spatial distribution image of the metal mark stripes; Specifically, the method includes: starting a mobile platform of the portable optical microscope and loading a preset grid scanning path; driving the lens of the portable optical microscope to scan the metal mark stripe coverage area on the surface of the carbon fiber reinforced resin-based composite material line by line through the mobile platform; adjusting the lens movement speed of the portable optical microscope to ensure that the lens covers each grid area of ​​the metal mark stripe coverage area; collecting images of the metal mark stripe coverage area in each grid area through the imaging component of the portable optical microscope; integrating the collected images in each grid area in the order of the grid scanning path to generate a spatial distribution image of the metal mark stripes; storing the spatial distribution image of the metal mark stripes in a storage device of the portable optical microscope; wherein the preset grid scanning path is determined based on the coordinate range of the suspected position of damage on the surface of the carbon fiber reinforced resin-based composite material and the field of view size of the portable optical microscope, for example, covering the metal mark stripe area with a 1mm×1mm grid area; Aim the portable X-ray diffractometer at the same metal marking stripe area, adjust the incident angle and focus position to ensure that the X-ray beam is incident on the surface of the metal marking stripe; the portable X-ray diffractometer is a lightweight X-ray device used for on-site analysis of the crystal structure of materials and is an existing device; Start the portable X-ray diffractometer to scan the metal marking stripes and obtain the crystal structure diffraction pattern; Specifically, the method includes: activating the portable X-ray diffractometer and initializing the X-ray emission source and detector; aligning the X-ray emission source of the portable X-ray diffractometer with the area covered by the metal mark stripes on the surface of the carbon fiber reinforced resin-based composite material; adjusting the X-ray emission source angle of the portable X-ray diffractometer to ensure that the X-ray beam is vertically incident on the surface of the metal mark stripes; driving the X-ray emission source and detector to scan point by point along the area covered by the metal mark stripes through the mobile platform of the portable X-ray diffractometer; collecting the X-ray diffraction signal generated by the metal mark stripes at each scanning point through the detector of the portable X-ray diffractometer; integrating the X-ray diffraction signals of all scanning points to generate a crystal structure diffraction pattern of the metal mark stripes; and storing the crystal structure diffraction pattern of the metal mark stripes in a storage device of the portable X-ray diffractometer. Extracting crystal structure diffraction peak intensity data of metal marker stripes from the crystal structure diffraction pattern; The spatial distribution image of the metal marker stripes is correlated and integrated with the crystal structure diffraction peak intensity data to generate a metal marker stripe dataset; Extract the distribution density, morphological features and crystal structure diffraction peak intensity variation trends from the metal marker stripe dataset; Compare the distribution density, morphological characteristics, and crystal structure diffraction peak intensity change trends with the preset damage feature template, and generate a structural damage verification report based on the comparison results; Extract data including standard distribution density, standard morphological features and standard crystal structure diffraction peak intensity from a preset damage feature template; the preset damage feature template is determined based on experimental data of carbon fiber reinforced resin-based composite materials under known damage types (such as microcracks and delamination); compare the distribution density of the metal marker stripes with the standard distribution density of the preset damage feature template one by one through the data analysis component; compare the morphological features of the metal marker stripes with the standard morphological features of the preset damage feature template; compare the crystal structure diffraction peak intensity data of the metal marker stripes with the standard crystal structure diffraction peak intensity of the preset damage feature template; record the degree of matching between the distribution density, morphological features and crystal structure diffraction peak intensity data of the metal marker stripes and the preset damage feature template; generate a structural damage verification report including the metal marker stripe distribution density, morphological features, crystal structure diffraction peak intensity data and damage type determination based on the degree of matching.

[0036] This embodiment also provides a computer device suitable for the structural damage detection method of carbon fiber reinforced resin-based composite materials, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the structural damage detection method of carbon fiber reinforced resin-based composite materials proposed in the above embodiment.

[0037] The computer device may be a terminal, comprising a processor, memory, a communication interface, a display, and an input device connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores an operating system and computer programs. The internal memory provides an environment for the operating system and computer programs stored in the non-volatile storage media. The communication interface of the computer device is used to communicate with external terminals via wired or wireless communication. Wireless communication may be achieved via Wi-Fi, a carrier network, NFC (near-field communication), or other technologies. The display of the computer device may be a liquid crystal display or an electronic ink display. The input device may be a touchscreen overlay on the display, buttons, a trackball, or a touchpad on the computer device housing, or an external keyboard, touchpad, or mouse.

[0038] This embodiment also provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the structural damage detection method for carbon fiber reinforced resin-based composite materials proposed in the above embodiment; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk.

[0039] In summary, the present invention achieves accurate capture of mechanical response anomalies by: comparing the resonant frequency data with the baseline resonant frequency data in the initial state, identifying the position where the frequency offset exceeds the preset threshold. At the same time, a plasma laser beam is applied to the frequency offset position to stimulate the plasmon polariton resonance on the surface of the composite sensitive coating, and the frequency shift of its optical near-field enhanced response spectrum is monitored to determine whether it exceeds the background noise fluctuation range; this dual judgment mechanism uses mechanical vibration and optical near-field enhanced dual signal cross-verification to avoid misjudgment caused by environmental interference on a single signal, significantly improving the reliability and sensitivity of damage identification; the micro-cantilever array and the composite sensitive coating work together to effectively sense the tiny deformations caused by microcracks and changes in the surface chemical environment, thereby achieving high-precision positioning and confirmation of early damage to carbon fiber reinforced resin-based composite materials.

[0040] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for detecting structural damage of carbon fiber reinforced resin-based composite materials, characterized by: include, Deploy a micro-cantilever beam array on the surface of the stress concentration location of the carbon fiber reinforced resin matrix composite material; The surface of the micro-cantilever array is covered with a composite sensitive coating; The resonance frequency data is collected in real time through the microcantilever array, and the composite sensitive coating on the surface of the microcantilever array is irradiated with a plasmon laser beam to stimulate plasmon polariton resonance. Determine the microcantilever array position where the resonance frequency data exceeds the reference offset threshold and the frequency shift of the plasmon polariton resonance exceeds the preset background noise fluctuation range as a suspected damage position; Electrochemical deposition is triggered by the coordinates of the suspected damage location, and a constant negative voltage is applied to the surface of the suspected damage location using the exposed carbon fiber of the carbon fiber reinforced resin-based composite material as a reference electrode to generate metal marking stripes; The spatial distribution image of the metal mark stripes is scanned by a portable optical microscope, and the crystal structure diffraction peak intensity data of the metal mark stripes is scanned by a portable X-ray diffractometer. A structural damage verification report is generated based on the distribution morphology and crystal structure diffraction peak intensity data.

2. The structural damage detection method of carbon fiber reinforced resin-based composite material according to claim 1, characterized in that: The micro cantilever beam array is deployed on the surface of the stress concentration position of the carbon fiber reinforced resin-based composite material, specifically as follows: Performing oxygen plasma treatment on the edge of the bolt hole and the curved surface transition area of ​​the carbon fiber reinforced resin matrix composite material to form a pre-treated area of ​​the carbon fiber reinforced resin matrix composite material; Nano-silver conductive adhesive is used to bond silicon-based micro-cantilever beams in the pretreatment area of ​​the carbon fiber reinforced resin-based composite material to form a rectangularly arranged micro-cantilever beam array.

3. The structural damage detection method of carbon fiber reinforced resin-based composite material according to claim 1, characterized in that: The real-time acquisition of resonance frequency data by the microcantilever array is as follows: Establishing electrical connection between the microcantilever array and the resonance frequency acquisition instrument; An alternating electrostatic excitation is applied to the microcantilever array through a resonance frequency acquisition instrument, the response frequency of the microcantilever array is scanned, and the resonance frequency value displayed by the resonance frequency acquisition instrument is read as the resonance frequency data of the microcantilever array.

4. The method for detecting structural damage of a carbon fiber reinforced resin-based composite material according to claim 1, wherein: The composite sensitive coating on the surface of the microcantilever array is irradiated with a plasma laser beam to excite plasmon polariton resonance, as follows: One end of the optical fiber is connected to the output port of the plasma laser emitting device, and the other end is led to the microcantilever array; Adjust the position and angle of the optical fiber outlet to align it with the composite sensitive coating on the surface of the micro-cantilever array, and keep the emission direction perpendicular to the surface of the composite sensitive coating; Starting the plasma laser emitting device, which outputs a plasma laser beam after being preheated and stabilized; The plasmon laser beam is transmitted to the composite sensitive coating on the surface of the microcantilever array through an optical fiber that is connected and aligned with the composite sensitive coating, thereby exciting plasmon polaritons resonance.

5. The method for detecting structural damage of a carbon fiber reinforced resin-based composite material according to claim 1, wherein: The determination of whether the resonant frequency data exceeds the reference offset threshold is as follows: Obtain the initial resonance frequency value of the micro-cantilever beam array under stress-free loading as the reference resonance frequency data; Comparing the real-time collected resonance frequency data of each position of the micro-cantilever array with the reference resonance frequency data of the corresponding position to determine the resonance frequency offset of each position of the micro-cantilever array; When the resonance frequency offset of a certain position of the micro-cantilever array is greater than a preset reference offset threshold, the plasmon polariton resonance frequency shift verification of the micro-cantilever array position where the resonance frequency offset exceeds the reference offset threshold is started.

6. The method for detecting structural damage of a carbon fiber reinforced resin-based composite material according to claim 5, wherein: The reference deflection threshold is determined according to the initial resonance frequency distribution of the micro-cantilever array in a stress-free state.

7. The method for detecting structural damage of a carbon fiber reinforced resin-based composite material according to claim 1, wherein: The position of the microcantilever array where the frequency shift of the plasmon polariton resonance exceeds the preset background noise fluctuation range is as follows: Under the condition of plasmon polariton resonance excitation, the optical near-field enhanced response spectrum of the composite sensitive coating is monitored to obtain the real-time resonance frequency of the plasmon polariton resonance; The real-time resonance frequency of the plasmon polariton resonance is compared with the initial resonance frequency value under the stress-free loading state to determine the frequency shift of the plasmon polariton resonance; When the frequency shift of the plasmon polariton resonance is greater than a maximum value of a preset background noise fluctuation range, it is determined that the frequency shift of the plasmon polariton resonance exceeds the background noise fluctuation range.

8. The method for detecting structural damage of a carbon fiber reinforced resin-based composite material according to claim 7, wherein: The background noise fluctuation range is determined based on the plasmon polariton resonance frequency fluctuation characteristics of the optical near-field enhanced response spectrum of the composite sensitive coating in a stress-free loading state.

9. The method for detecting structural damage of a carbon fiber reinforced resin-based composite material according to claim 1, wherein: The coordinates of the suspected damage location are used to trigger electrochemical deposition, and the exposed carbon fiber of the carbon fiber reinforced resin-based composite material is used as a reference electrode. A constant negative voltage is applied to the surface of the suspected damage location to generate metal marking stripes, as follows: According to the coordinates of the suspected damage location, the electrochemical deposition probe is driven to move to the top of the suspected damage location; Connecting the exposed carbon fiber of the carbon fiber reinforced resin matrix composite material to the reference electrode interface of the electrochemical controller as a reference electrode for electrochemical deposition; Activating the electrolyte release component of the electrochemical deposition probe to release electrolyte containing metal ions onto the surface of the suspected damage location, thereby forming a local electrochemical reaction area; In the local electrochemical reaction area, a constant negative voltage is applied between the electrochemical deposition probe and the exposed carbon fibers of the carbon fiber reinforced resin matrix composite material through an electrochemical controller; Under a constant negative voltage, metal ions are reduced and deposited on the surface of suspected damage locations, forming metal deposition spots; A constant negative voltage is continuously applied until the metal deposition spot grows to a size that can be identified by optical means, outputting a metal marking stripe.

10. The method for detecting structural damage of a carbon fiber reinforced resin-based composite material according to claim 1, wherein: The portable optical microscope is used to scan the spatial distribution image of the metal mark stripes, and the portable X-ray diffractometer is used to scan the crystal structure diffraction peak intensity data of the metal mark stripes. Based on the distribution morphology and crystal structure diffraction peak intensity data, a structural damage verification report is generated, as follows: A portable optical microscope is aligned with the location area of ​​the metal marking stripes on the surface of the carbon fiber reinforced resin matrix composite material, the focal length and light source of the portable optical microscope are adjusted, and the portable optical microscope is driven to scan the area covered by the metal marking stripes along a grid scanning path, and a spatial distribution image of the metal marking stripes is recorded; Start the portable X-ray diffractometer to scan the metal marking stripes and obtain the crystal structure diffraction pattern; Extract the crystal structure diffraction peak intensity data of the metal marking stripes from the diffraction pattern.

Images