Carbon fiber composite material damage detection system and method

Abstract

The invention discloses a damage detection system for a carbon fiber composite material. The damage detection system comprises a mechanical arm, a first group of detection plates, a second group of detection plates, a constant current source, an ampere meter and a processor, each of the first group of measuring plates and the second group of measuring plates comprises two measuring plate assemblies, and the two measuring plate assemblies in the first group of measuring plates are respectively arranged on the top surface and the bottom surface of the carbon fiber composite material; the two measuring plate assemblies in the second group of measuring plates are respectively arranged on two opposite side surfaces of the carbon fiber composite material; the mechanical arm controls the first group of measuring plates and the second group of measuring plates to move on the carbon fiber composite material; the output end of one measuring plate assembly is connected with the positive electrode of the constant current source, and the ampere meter is connected in series between the negative electrode of the constant current source and the output end of the other measuring plate assembly; the processor obtains the coordinates of the damage position of the carbon fiber composite material according to the obtained current data. According to the invention, the efficiency and precision of composite material damage detection are improved, the related cost is greatly reduced, and the safety and reliability of material use are enhanced at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of material damage detection, and particularly to a damage detection system and method for carbon fiber composite materials. Background Art

[0002] The carbon fiber composite material industry is in a booming golden period. It is not only a key force driving industrial upgrading but also a typical representative of new quality productivity. Carbon fiber composite materials have the advantages of high specific strength, high specific modulus, and excellent designability, and are widely used in many cutting-edge fields such as aerospace, ships and vehicles, consumer electronics, construction engineering, and robot manufacturing. However, potential structural defects are inevitable during the manufacturing process of carbon fiber composite materials, and structural damage and aging phenomena such as internal fiber fracture are inevitable during long-term service. These potential damages are often imperceptible to the naked eye, but they can reduce the mechanical strength of the material by more than half, seriously threatening the structural stability of the composite material. Therefore, it is urgent to develop a technical measure that can perform non-destructive detection on potential damages of carbon fiber composite materials and evaluate their mechanical properties.

[0003] In the field of non-destructive damage detection of carbon fiber composite materials, the most widely used non-destructive detection methods mainly include ultrasonic detection method, CT detection, acoustic emission detection, and infrared thermography, etc.

[0004] Patent CN202211360912.0 discloses an ultrasonic quantitative evaluation device and method for impact damage of carbon fiber composite materials. The invention provides an ultrasonic detection method for damage of carbon fiber composite materials, which can perform quantitative analysis on defects and evaluate mechanical properties, and realize rapid and accurate quantitative detection of impact damage defects of carbon fiber composite materials. However, the system of this method is relatively complex, the operation and maintenance cost is high, it is easily interfered by environmental factors, and the requirements for the detection environment are high.

[0005] Patent CN202110470207.5 discloses a non-destructive detection method for defects in composite materials based on generative thermography. This detection method combines thermography technology with a generative adversarial network model to realize feature extraction of thermal image data and background weakening, thereby improving the accuracy and reliability of infrared thermography detection of internal defects in polymers. However, this method also has some limitations, such as a long damage detection time, the result being a planar image, and low detection accuracy, etc.

[0006] The invention patent CN202010821919.2 discloses a test method for the study of the tensile-tensile fatigue damage evolution of carbon fiber / epoxy resin three-dimensional woven composites based on synchrotron radiation CT. This method conducts damage detection through synchrotron radiation CT and realizes the damage observation of three-dimensional woven composites. However, the operation process of this method is relatively cumbersome, requiring a long test time and high material costs, and it is difficult to implement for operators without relevant skills. Summary of the Invention

[0007] Aiming at the deficiencies in the prior art, the present invention provides a carbon fiber composite material damage detection system and method to solve the technical problems such as high operation and maintenance costs, easy interference in the detection process, low detection accuracy, and cumbersome detection process in the prior art.

[0008] The present invention provides a carbon fiber composite material damage detection system, including: a robotic arm, a first set of measuring plates, a second set of measuring plates, a constant current source, an ammeter, and a processor;

[0009] Both the first set of measuring plates and the second set of measuring plates include two measuring plate components. The two measuring plate components in the first set of measuring plates are respectively arranged on the top surface and the bottom surface of the carbon fiber composite material; the two measuring plate components in the second set of measuring plates are respectively arranged on two opposite side surfaces of the carbon fiber composite material; the measuring plate component includes: a flat plate, a copper measuring point, a connecting column, and a circuit controller; several copper measuring points are evenly distributed on the surface of the flat plate in contact with the carbon fiber composite material; the connecting column is vertically arranged on the other surface of the flat plate in contact with the carbon fiber composite material; the circuit controller is connected to several copper measuring points, and the circuit controller is used to adjust the connection between the copper measuring points to be in series or parallel; the robotic arm is connected to the connecting column, and the robotic arm controls the first set of measuring plates to move on the top surface and the bottom surface of the carbon fiber composite material; the robotic arm controls the second set of measuring plates to move horizontally on two opposite side surfaces of the carbon fiber composite material; the output end of the circuit controller on one side of the two measuring plate components is connected to the positive pole of the constant current source, and the ammeter is connected in series between the negative pole of the constant current source and the output end of the circuit controller on the other side; the processor is connected to the ammeter and is used to obtain the damage position coordinates of the carbon fiber composite material according to the acquired current data.

[0010] Further, the carbon fiber composite material damage detection system further includes: a resistor; the resistor is connected in series between the output end of the circuit controller on one side and the positive pole of the constant current source.

[0011] Further, the distribution of the copper measuring points on the flat plate corresponds to the carbon fiber bundles in the carbon fiber composite material.

[0012] The present invention also provides a detection method for the carbon fiber composite material damage detection system, including:

[0013] Step 1: Polish the surface of the carbon fiber composite material until the carbon fiber bundles are exposed;

[0014] Step 2: Apply a conductive coating on the surface of the carbon fiber composite material;

[0015] Step 3: Construct a three-dimensional coordinate system, with the extension direction of the carbon fiber bundles as the y-axis direction, the horizontal direction perpendicular to the extension direction of the carbon fiber bundles as the x-axis direction, and the height direction of the carbon fiber composite material as the z-axis direction;

[0016] Conduct a rough measurement process for the damaged area. The specific process is as follows:

[0017] Set the copper measurement points in full parallel connection, and obtain the rough coordinates of the damaged area according to the moving speeds of the first set of measurement plates and the second set of measurement plates and the collected current;

[0018] Step 4: Conduct a precise measurement process for the damaged area. The specific process is as follows:

[0019] Set the copper measurement points in series connection, and obtain the precise coordinates of the damaged area according to the moving speeds of the first set of measurement plates and the second set of measurement plates and the collected current.

[0020] Further, after the said Step 4, it also includes: a mechanical damage assessment process.

[0021] Further, the specific method for obtaining the rough coordinates of the damaged area in Step 3 is as follows:

[0022] Step 31: Control the second set of measurement plates to move along the x-axis direction at a preset speed, and collect the current data at each moment;

[0023] Step 32: Construct a coordinate system of current and time, and obtain the start time and end time of the current fluctuation whose current fluctuation is greater than the preset fluctuation amount;

[0024] Step 33: Calculate the start coordinate and end coordinate of the damaged area in the x-axis direction according to the preset speed movement, the start time and end time of the current fluctuation;

[0025] Step 34: Control the first set of measurement plates to move along the y-axis direction within the x-axis range of the coordinates obtained in Step 33 at a preset speed, and collect the current data at each moment;

[0026] Step 35: Construct a coordinate system of current and time, and obtain the start time and end time of the current fluctuation whose current fluctuation is greater than the preset fluctuation amount;

[0027] Step 36: Calculate the start coordinate and end coordinate of the damaged area in the y-axis direction according to the preset speed movement, the start time and end time of the current fluctuation.

[0028] Further, the specific method for obtaining the precise coordinates of the damaged area in Step 4 is as follows:

[0029] Step 41: Control the second set of test plates to move between the starting coordinate and the ending coordinate in the x-axis direction of the damaged area at a preset speed, and collect the current data of each copper measuring point at each moment.

[0030] Step 42: Control the first set of test plates to move between the starting coordinate and the ending coordinate in the y-axis direction of the damaged area at a preset speed, and collect the current data of each copper measuring point at each moment.

[0031] Step 43: Obtain the coordinates of the copper measuring points corresponding to the current exceeding the preset error.

[0032] Step 44: Construct a three-dimensional spatial network of the current distribution in the damaged area according to the coordinates obtained in Step 43, and each grid corresponds to two current values respectively.

[0033] Further, after the said Step 36, a verification process is also included, and the specific steps are as follows:

[0034] Step 37: Control the first set of test plates to move within the x-axis range of the coordinates obtained in Step 33 along the x-axis direction, and collect the current data at each moment.

[0035] Step 38: Construct a coordinate system of current and time, and obtain the start time and end time of the current fluctuation whose current fluctuation is greater than the preset fluctuation amount.

[0036] Step 39: Calculate the starting coordinate and the ending coordinate of the damaged area in the x-axis direction according to the preset speed, the start time of the current fluctuation, and the end time of the current fluctuation.

[0037] Step 310: When the coordinates obtained in Step 39 are the same as the coordinates obtained in Step 33, the verification is completed.

[0038] When the coordinates obtained in Step 39 are different from the coordinates obtained in Step 33, taking the origin of the coordinate system as the starting point, control the first set of test plates to move in a snake-like shape with the movement along the x-axis as the initial direction; obtain the current fluctuation times with the current volatility greater than 5%, and calculate the corresponding planar coordinates of the damaged area.

[0039] Further, the mechanical damage assessment process includes the following steps:

[0040] Step 51: Perform resistivity conversion on the two corresponding current values in each grid obtained in Step 44.

[0041] Step 52: Construct a macroscopic mechanical property static experiment to obtain the experimental data of resistivity and mechanical property damage.

[0042] Step 53: Construct a finite element model to obtain the simulation data of resistivity and mechanical property damage.

[0043] Step 54: Use the experimental data obtained in Step 52 and the simulation data obtained in Step 53 as the training set of the mechanical damage assessment model to train the mechanical damage assessment model;

[0044] Step 55: Obtain the mechanical damage assessment result of the carbon fiber composite material through the trained mechanical damage assessment model using the resistivity obtained in Step 51.

[0045] Advantages of the present invention:

[0046] The present invention greatly simplifies the damage detection process through automated operation, eliminates the dependence on highly skilled operators, reduces labor costs, and improves the consistency and reliability of detection. It not only improves work efficiency but also ensures the accuracy of detection results.

[0047] The equipment required by the present invention is simple and low-cost, significantly reducing the time and economic costs of detection. This low-cost and high-efficiency solution enables more enterprises and research institutions to implement high-quality damage detection services, promoting the application and development of composite materials.

[0048] The present invention realizes a three-dimensional assessment of internal damage, providing important support for comprehensively understanding the damage condition of composite materials. Through precise three-dimensional analysis, the present invention can more accurately predict the overall mechanical properties of materials, thereby providing a scientific basis for subsequent repair or replacement decisions.

[0049] Based on the detailed damage assessment results, the present invention can implement targeted maintenance strategies for specific damage conditions in different regions, such as local replacement or reinforcement. It not only improves the efficiency and effect of maintenance work but also ensures the performance stability and safety of composite materials during service, extends the service life of materials, and reduces potential safety hazards and economic losses caused by sudden failures.

[0050] Through its innovative detection methods and technologies, the present invention not only improves the efficiency and accuracy of composite material damage detection but also significantly reduces related costs, while enhancing the safety and reliability of material use. It has important application value and broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings. The drawings are schematic and should not be construed as imposing any limitation on the present invention. In the drawings:

[0052] Figure 1 is a schematic diagram of the initial position of the first group of test plates in a specific embodiment of the present invention;

[0053] Figure 2 is a schematic diagram of the initial position of the second group of test plates in a specific embodiment of the present invention;

[0054] Figure 3 It is a schematic diagram of the test board assembly in a specific embodiment of the present invention;

[0055] Figure 4 It is a schematic diagram of the path of the first group of test board serpentine movement during the calibration process in a specific embodiment of the present invention. Detailed implementation manners

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

[0057] The present invention will be further illustrated below with specific embodiments. Those skilled in the art should understand that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. Modifications to various equivalent forms of the present invention fall within the scope defined by the appended claims of this application.

[0058] As Figures 1-4 shown, the present invention provides a carbon fiber composite material damage detection system, including: a robotic arm 1, a first group of test boards 2, a second group of test boards 7, a constant current source 10, a resistor 9, an ammeter 11, and a processor 12;

[0059] Both the first group of test boards 2 and the second group of test boards 7 include two test board assemblies. The two test board assemblies in the first group of test boards 2 are respectively arranged on the top surface and the bottom surface of the carbon fiber composite material 5; the two test board assemblies in the second group of test boards 7 are respectively arranged on two opposite side surfaces of the carbon fiber composite material 5; the test board assembly includes: a flat plate 105, a copper measuring point 101, a connecting column 103, and a circuit controller 104; several copper measuring points 101 are evenly distributed on the surface of the flat plate 105 in contact with the carbon fiber composite material 5. The distribution of the copper measuring points 101 on the flat plate 105 corresponds to the carbon fiber bundles in the carbon fiber composite material 5, and corresponds to the thickness of a single-layer carbon fiber ply, generally 0.2mm * 0.2mm;

[0060] The connecting column 103 is vertically arranged on the other side of the flat plate 105 in contact with the carbon fiber composite material 5; the circuit controller 104 is connected to several copper measuring points 101 through internal wires 102, and the circuit controller 104 is used to adjust the connection between the copper measuring points 101 to be in series or parallel; the robotic arm 1 is connected to the connecting column 103, and the robotic arm 1 controls the first set of measuring plates 2 to move on the top and bottom surfaces of the carbon fiber composite material 5; the robotic arm 1 controls the second set of measuring plates 7 to move horizontally on two opposite side surfaces of the carbon fiber composite material 5; a resistor 9 is connected in series between the output terminal of the circuit controller 104 on one side in two measuring plate assemblies and the positive pole of the constant current source 10, and an ammeter 11 is connected in series between the negative pole of the constant current source 10 and the output terminal of the circuit controller 104 on the other side; the processor 12 is connected to the ammeter 11 and is used to obtain the damage position coordinates of the carbon fiber composite material 5 according to the acquired current data.

[0061] Figure 1 Among them, the moving path 3 of the first set of measuring plates 2 is to move along the X-axis and Y-axis respectively, forming a cross shape, and the moving path 3 passes through the damaged position 4. Figure 2 Among them, the moving path 3 of the second set of measuring plates 7 is to move layer by layer along the X-axis direction in the Z-axis direction. Figure. Figure 4 Among them, the moving path 3 of the first set of measuring plates 2 is in a snake shape.

[0062] The present invention also provides a detection method for a carbon fiber composite material damage detection system, including:

[0063] Step 1: It is required to polish the directions parallel to the fiber layer direction and the vertical cross-section direction respectively, so that the carbon fiber bundles in the carbon fiber composite material are exposed and the polished surface is flat;

[0064] Step 2: A conductive coating 6 is coated between the surface of the carbon fiber composite material and the flat plate to facilitate the uniform translation of the flat plate;

[0065] Perform circuit internal resistance detection, specifically:

[0066] Short-circuit the two ends of the second set of measuring plates and the first set of measuring plates respectively to obtain the horizontal current I x0 and the vertical current I y0 , knowing the output voltage V0 of the constant current source, the circuit internal resistance R x0 and R y0 can be easily obtained through Ohm's law;

[0067] Step 3: Construct a three-dimensional coordinate system, with the extending direction of the carbon fiber bundle as the y-axis direction, the direction horizontally perpendicular to the extending direction of the carbon fiber bundle as the x-axis direction, and the height direction of the carbon fiber composite material as the z-axis direction;

[0068] In the process of roughly measuring the damaged area, set the copper measuring points in parallel. Obtain the precise coordinates of the damaged area according to the moving speeds of the first set of measuring plates and the second set of measuring plates and the collected current. The specific process is as follows:

[0069] Step 31: Control the second set of measuring plates to move along the x-axis direction at a preset speed v x and collect the current data at each moment;

[0070] Step 32: Construct a coordinate system of current and time, and obtain the start time t x1 and end time t x2 of the current fluctuation whose current fluctuation rate is greater than 5%; Those with a current fluctuation rate less than 5% are considered system errors;

[0071] Step 33: Calculate the starting coordinate v x t x1 and ending coordinate v x t x2 of the damaged area in the horizontal direction according to the preset speed movement, current fluctuation start time and end time;

[0072] Step 34: Control the first set of measuring plates to move along the y-axis direction within the x-axis range of the coordinates obtained in Step 33 at a preset speed v y and collect the current data at each moment;

[0073] Step 35: Construct a coordinate system of current and time, and obtain the start time t y1 and end time t y2 of the current fluctuation whose current fluctuation is greater than the preset fluctuation amount;

[0074] Step 36: Calculate the starting coordinate v y t y1 and ending coordinate v y t y2 of the damaged area in the y-axis direction according to the preset speed movement, current fluctuation start time and end time;

[0075] Step 37: Control the first set of measuring plates to move along the x-axis direction within the x-axis range of the coordinates obtained in Step 33, and collect the current data at each moment;

[0076] Step 38: Construct a coordinate system of current and time, and obtain the start time t yx1 and end time t yx2 of the current fluctuation whose current fluctuation is greater than the preset fluctuation amount;

[0077] Step 39: Calculate the starting coordinate v x t yx1 and ending coordinate v of the damaged area in the x-axis directionx t yx2 ;

[0078] Step 310: When the coordinates obtained in Step 39 are the same as those obtained in Step 33, the verification is completed;

[0079] When the coordinates obtained in Step 39 are different from those obtained in Step 33, as Figure 4 shown, starting from the origin of the coordinate system 0, control the first set of measuring plates to move in a serpentine manner with the initial direction along the x-axis; the moving speed is v, and record the current fluctuation times t1~t2, t2~t3,..., t3~t for multiple segments where the current volatility is greater than 5%; n then calculate the plane coordinates corresponding to the damaged area according to the moving path of the measuring plates and the geometric dimensions of the material;

[0080] Step 4: Carry out the precise measurement process of the damaged area. Set the copper measuring points in series, and obtain the precise coordinates of the damaged area according to the moving speeds of the first set of measuring plates and the second set of measuring plates and the collected current. The specific process is as follows:

[0081] Step 41: Control the second set of measuring plates to move at a preset speed between the starting coordinate and the ending coordinate in the x-axis direction of the damaged area, and collect the current data of each copper measuring point at each moment;

[0082] Step 42: Control the first set of measuring plates to move at a preset speed between the starting coordinate and the ending coordinate in the y-axis direction of the damaged area, and collect the current data of each copper measuring point at each moment;

[0083] Step 43: Take 5% as the error. The part where the current is significantly higher or lower than the non-damaged area is the damage, and obtain the coordinates of the copper measuring points corresponding to when the current exceeds 5%;

[0084] Step 44: Construct a three-dimensional spatial network of the current distribution in the damaged area according to the coordinates obtained in Step 43. Each grid corresponds to two current values, in the horizontal y-axis direction and the vertical x-axis direction

[0085] Step 5: The mechanical damage assessment process includes the following steps:

[0086] Step 51: Convert the two corresponding current values in each grid obtained in Step 44 into resistivity;

[0087] First, convert the in the horizontal y-axis direction and in the vertical x-axis direction into resistivity respectively to remove the influence of the material size; the overall resistance and Subtract the circuit internal resistances R in Step 2 respectively x0 and R y0 , and then according to the resistivity formula:

[0088] ρ = RS / L

[0089] where S is the area of the copper measuring point 101; L are the carbon fiber length and the sample thickness respectively;

[0090] the corresponding resistivity can be obtained and represent carbon fiber damage and interlayer damage respectively;

[0091] Step 52: Construct a static experiment on macroscopic mechanical properties to obtain experimental data on resistivity and mechanical property damage;

[0092] Design and fabricate carbon fiber / epoxy resin unidirectional reinforced composite material samples with different carbon fiber contents and different ply thicknesses as equivalent substitutes respectively, and then conduct static experiments on the macroscopic mechanical properties of these homogeneous samples, so as to obtain the elastic moduli in the horizontal direction and the ply direction respectively. Taking the carbon fiber composite material as the reference elastic modulus E0, calculate the damage coefficient D = △E / E0 of the mechanical properties, and finally measure the corresponding resistivities in the horizontal direction and the ply direction of these samples, so as to obtain the experimental data on the resistivity and mechanical property damage of the unidirectional reinforced composite material samples;

[0093] Step 53: Construct a finite element model to obtain simulation data on resistivity and mechanical property damage;

[0094] Combining the elastoplastic constitutive equation and the damage mechanics theoretical model, simulate and calculate the simulation data on the resistivity and mechanical property damage of different carbon fiber / epoxy resin single-layer composite material samples through the finite element model, as a supplement to the experimental data in Step 52;

[0095] Step 54: Use the experimental data obtained in Step 52 and the simulation data obtained in Step 53 as the training set of the mechanical damage assessment model, and feed them into the mechanical damage assessment model with an artificial neural network for deep learning respectively, so as to obtain the mechanical damage assessment model of the composite material along the carbon fiber direction and the ply direction corresponding to any horizontal and vertical resistivities;

[0096] Step 55: Obtain the mechanical damage assessment results of the carbon fiber composite material through the trained mechanical damage assessment model for the resistivities and obtained in Step 51, so as to generate a spatial distribution cloud map of the damage of the entire carbon fiber composite material sample to be measured.

[0097] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A carbon fiber composite material damage detection system, characterized in that, Including: A robotic arm, a first set of measuring plates, a second set of measuring plates, a constant current source, an ammeter, and a processor; Both the first set of measuring plates and the second set of measuring plates each include two measuring plate components. The two measuring plate components in the first set of measuring plates are respectively arranged on the top surface and the bottom surface of the carbon fiber composite material; the two measuring plate components in the second set of measuring plates are respectively arranged on two opposite side surfaces of the carbon fiber composite material; the measuring plate component includes: a flat plate, a copper measuring point, a connecting column, and a circuit controller; several copper measuring points are evenly distributed on the surface of the flat plate in contact with the carbon fiber composite material; The connecting column is vertically arranged on the other surface of the flat plate in contact with the carbon fiber composite material; the circuit controller is connected to several copper measuring points, and the circuit controller is used to adjust the connection between the copper measuring points to be in series or parallel; the robotic arm is connected to the connecting column, and the robotic arm controls the first set of measuring plates to move on the top surface and the bottom surface of the carbon fiber composite material; the robotic arm controls the second set of measuring plates to move horizontally on two opposite side surfaces of the carbon fiber composite material; the output end of the circuit controller on one side of the two measuring plate components is connected to the positive pole of the constant current source, and the ammeter is connected in series between the negative pole of the constant current source and the output end of the circuit controller on the other side; the processor is connected to the ammeter and is used to obtain the damage position coordinates of the carbon fiber composite material according to the acquired current data.

2. The carbon fiber composite material damage detection system according to claim 1, wherein The carbon fiber composite material damage detection system further includes: a resistor; the resistor is connected in series between the output end of the circuit controller on one side and the positive pole of the constant current source.

3. The carbon fiber composite material damage detection system according to claim 1 or 2, characterized in that, The distribution of the copper measuring points on the flat plate corresponds to the carbon fiber bundles in the carbon fiber composite material.

4. A detection method for a carbon fiber composite material damage detection system, applicable to the carbon fiber composite material damage detection system described in any one of claims 1-3, characterized in that, The method includes the following steps: Step 1: Polish the surface of the carbon fiber composite material until the carbon fiber bundles are exposed; Step 2: Apply a conductive coating on the surface of the carbon fiber composite material; Step 3: Construct a three-dimensional coordinate system, with the extending direction of the carbon fiber bundles as the y-axis direction, the horizontal direction perpendicular to the extending direction of the carbon fiber bundles as the x-axis direction, and the height direction of the carbon fiber composite material as the z-axis direction; Perform the rough measurement process of the damaged area, and the specific process is as follows: Set the copper measuring points to be all in parallel, and obtain the rough coordinates of the damaged area according to the moving speeds of the first set of measuring plates and the second set of measuring plates and the collected current; Step 4: Perform the fine measurement process of the damaged area, and the specific process is as follows: Set the copper measuring points to be in series, and obtain the accurate coordinates of the damaged area according to the moving speeds of the first set of measuring plates and the second set of measuring plates and the collected current.

5. The detection method of the carbon fiber composite material damage detection system according to claim 4, characterized in that, After the step 4, it further includes: a mechanical damage assessment process.

6. The detection method of the carbon fiber composite material damage detection system according to claim 4, characterized in that The specific method for obtaining the rough coordinates of the damaged area in the step 3 is as follows: Step 31: Control the second set of measuring plates to move along the x-axis direction at a preset speed, and collect the current data at each moment; Step 32: Construct a coordinate system of current and time, and obtain the start time and end time of the current fluctuation whose current fluctuation is greater than the preset fluctuation amount; Step 33: Calculate the starting coordinate and the ending coordinate of the damaged area in the x-axis direction according to the preset speed movement, the start time and the end time of the current fluctuation; Step 34: Control the first set of measuring plates to move along the y-axis direction within the x-axis range of the coordinates obtained in the step 33 at a preset speed, and collect the current data at each moment; Step 35: Construct a coordinate system of current versus time, and obtain the start time and end time of the current fluctuation where the current fluctuation is greater than the preset fluctuation amount; Step 36: Calculate the starting coordinate and ending coordinate of the damaged area in the y-axis direction according to the preset speed, the start time and end time of the current fluctuation.

7. The detection method of the carbon fiber composite material damage detection system according to claim 4, characterized in that The specific method for obtaining the accurate coordinates of the damaged area in Step 4 is as follows: Step 41: Control the second set of measuring plates to move at a preset speed between the starting coordinate and ending coordinate of the damaged area in the x-axis direction, and collect the current data of each copper measuring point at each moment; Step 42: Control the first set of measuring plates to move at a preset speed between the starting coordinate and ending coordinate of the damaged area in the y-axis direction, and collect the current data of each copper measuring point at each moment; Step 43: Obtain the coordinates of the copper measuring points corresponding to the current exceeding the preset error; Step 44: Construct a three-dimensional spatial network of the current distribution of the damaged area according to the coordinates obtained in Step 43, and each grid corresponds to two current values respectively.

8. The detection method of the carbon fiber composite material damage detection system according to claim 6, characterized in that, After Step 36, there is also a verification process, and the specific steps are as follows: Step 37: Control the first set of measuring plates to move along the x-axis within the x-axis range of the coordinates obtained in Step 33, and collect the current data at each moment; Step 38: Construct a coordinate system of current versus time, and obtain the start time and end time of the current fluctuation where the current fluctuation is greater than the preset fluctuation amount; Step 39: Calculate the starting coordinate and ending coordinate of the damaged area in the x-axis direction according to the preset speed, the start time and end time of the current fluctuation; Step 310: When the coordinates obtained in Step 39 are the same as the coordinates obtained in Step 33, the verification is completed; When the coordinates obtained in Step 39 are different from the coordinates obtained in Step 33, starting from the origin of the coordinate system 0, control the first set of measuring plates to move in a snake-like manner with the initial direction of moving along the x-axis; obtain multiple periods of current fluctuation time with a current fluctuation rate greater than 5%, and calculate the corresponding planar coordinates of the damaged area.

9. The detection method of the carbon fiber composite material damage detection system according to claim 5, characterized in that, The mechanical damage assessment process includes the following steps: Step 51: Perform resistivity conversion on the two corresponding current values in each grid obtained in Step 44; Step 52: Construct a static experiment of macroscopic mechanical properties, and obtain the experimental data of resistivity and mechanical property damage; Step 53: Construct a finite element model, and obtain the simulation data of resistivity and mechanical property damage; Step 54: Use the experimental data obtained in Step 52 and the simulation data obtained in Step 53 as the training set of the mechanical damage assessment model to train the mechanical damage assessment model; Step 55: Obtain the mechanical damage assessment result of the carbon fiber composite material through the trained mechanical damage assessment model with the resistivity obtained in Step 51.

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