Conductive lightning protection material current-carrying test system and method

Abstract

The present invention belongs to the field of current-carrying test of conductive lightning protection materials, and provides a current-carrying test system and method for conductive lightning protection materials to solve the problem of inaccurate current-carrying test of conductive lightning protection materials at present. Among them, the sample electrode clamping module in the current-carrying test system for conductive lightning protection materials is arranged in an environmental chamber, and the conductive lightning protection material is fixed on the sample electrode clamping module; the control module is used to control the discharge module to simulate lightning discharge; the electric signal acquisition module, the temperature measurement module and the image acquisition module synchronously collect the voltage signal and the current signal of the conductive lightning protection material and the temperature and damage morphology image at the same position on the surface of the conductive lightning protection material and transmit them to the control module; the control module is used to construct the relationship between the current-carrying resistance of the conductive lightning protection material and the temperature and the damage state of the conductive lightning protection material at the corresponding temperature, which can realize the temperature rise mode of self-heating of the lightning current-carrying electric Joule heat, and accurately obtain the resistance change of the material during the lightning current-carrying process.

Description

Technical Field

[0001] The invention belongs to the field of current-carrying test of conductive lightning protection materials, and in particular relates to a current-carrying test system and method for conductive lightning protection materials. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] The protection principle of lightning protection materials is to use their excellent electrical conductivity to divert lightning current from the surface of the structure, dissipate lightning energy, and prevent the protected internal structure from being damaged. Therefore, the change in the electrical conductivity of lightning protection materials during lightning strikes is the key to their protection performance.

[0004] During a lightning strike, the conductive composite material can conduct lightning current and generate Joule heat in the process of conducting current, causing damage to the resin matrix such as pyrolysis and ablation. Therefore, determining the change in the conductive properties of the conductive composite material during a lightning strike requires two necessary research conditions: (1) using the material heating method of current-carrying electrical Joule heating; and (2) considering the effects of material temperature and thermal reaction degree on the conductive properties.

[0005] Therefore, there is an urgent need for a current-carrying test system and method for conductive lightning protection materials that can realize a temperature-rising mode of self-heating by Joule heat induced by lightning current and can accurately obtain the resistance change of the material during lightning current carrying. Summary of the invention

[0006] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a conductive lightning protection material current-carrying test system and method, which can realize the temperature rise mode of self-heating of electric Joule heat caused by lightning current-carrying, and accurately obtain the resistance change of the material during lightning current-carrying process.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A first aspect of the present invention provides a current-carrying test system for conductive lightning protection materials.

[0009] A current-carrying test system for conductive lightning protection materials, comprising: a discharge module, an environmental chamber, a sample electrode clamping module, a temperature measurement module, an image acquisition module, an electrical signal acquisition module and a control module;

[0010] The sample electrode clamping module is arranged in the environmental chamber, and a conductive lightning protection material is fixed on the sample electrode clamping module; the discharge module is connected to the control module and the sample electrode clamping module respectively, and the control module is used to control the discharge module to simulate lightning discharge;

[0011] The temperature measurement module and the image acquisition module are co-focally arranged above the conductive lightning protection material; the electrical signal acquisition module, the temperature measurement module and the image acquisition module synchronously collect the voltage signal and the current signal of the conductive lightning protection material and the temperature and damage morphology image at the same position on the surface of the conductive lightning protection material and transmit them to the control module;

[0012] The control module is used to construct the relationship between the current-carrying resistance of the conductive lightning protection material and the temperature and the damage state of the conductive lightning protection material at the corresponding temperature based on the synchronously received voltage signal and current signal, temperature signal and damage morphology image.

[0013] As an implementation manner, optical glass windows are provided at positions where the temperature measurement module and the image acquisition module are opposite to the environmental chamber.

[0014] As an implementation manner, the temperature measurement module and the image acquisition module are respectively fixed on the optical glass window at a preset position through corresponding sleeves.

[0015] As an implementation mode, a rotatable component is provided in the sleeve for fine-tuning the temperature measurement module and the image acquisition module to achieve multi-point confocal.

[0016] As an implementation manner, the temperature measurement module is composed of at least one infrared temperature measurement probe and an infrared thermal imager, so as to simultaneously measure high-frequency temperature point data and low-frequency temperature distribution data of the conductive lightning protection material.

[0017] As an implementation mode, the control module is used to splice the temperature signals transmitted by the infrared temperature measuring probe and the infrared thermal imager to obtain a complete temperature curve during the test process.

[0018] As an implementation mode, the control module is used to calculate the resistance of the conductive lightning protection material at the corresponding test time point based on the synchronously received voltage signal and current signal, and then draw a conductive composite material current-carrying resistance-temperature relationship curve based on the temperature signal at the corresponding test time point.

[0019] As an implementation mode, a trained image classification model is pre-stored in the control module, and the damage degree of the damage morphology image is classified based on the image classification model to obtain the corresponding damage degree.

[0020] As an implementation mode, the atmosphere and air pressure in the environmental box are controllable.

[0021] A second aspect of the present invention provides a testing method based on a current-carrying testing system for conductive lightning protection materials.

[0022] A testing method based on a current-carrying testing system for conductive lightning protection materials, comprising:

[0023] Fix the conductive lightning protection material on the sample electrode clamping module, and adjust the atmosphere and air pressure in the environmental box to the preset environment;

[0024] The control discharge module simulates lightning discharge and acts on the conductive lightning protection material;

[0025] Synchronously collect the voltage signal and current signal of the conductive lightning protection material and the temperature and damage morphology image at the same position on the surface of the conductive lightning protection material;

[0026] According to the synchronously received voltage signal, current signal, temperature signal and damage morphology image, the relationship between the current-carrying resistance of the conductive lightning protection material and the temperature and the damage state of the conductive lightning protection material at the corresponding temperature are constructed.

[0027] The beneficial effects of the present invention are:

[0028] (1) The present invention provides a current-carrying test system and method for conductive lightning protection materials. By synchronously collecting the voltage signal and current signal of the conductive lightning protection material and the temperature and damage morphology images at the same position on the surface of the conductive lightning protection material, the accuracy of constructing the current-carrying resistance-temperature-damage correspondence relationship of the conductive lightning protection material is ensured, and the lightning protection performance evaluation capability and efficiency of the conductive lightning protection material are significantly improved, providing strong technical support for the lightning protection research and application development of the conductive lightning protection material.

[0029] (2) The present invention utilizes a control module to accurately control the current or voltage size, waveform and application time of the discharge module, and can control the atmosphere and vacuum degree of the environment in which the sample material is located. It can also accurately measure the changes in temperature and conductivity at the same position of the material within an extremely wide temperature range, and synchronously record key parameters such as current, voltage and temperature in real time. It is particularly suitable for evaluating the lightning protection performance of conductive lightning protection materials in lightning protection fields such as aerospace, wind power, and new energy vehicles, and can be widely expanded to any field that requires precise resistance-temperature characteristic testing.

[0030] (3) The present invention uses an infrared temperature measuring probe and an infrared thermal imager to simultaneously measure the high-frequency temperature point data and low-frequency temperature distribution data of the conductive lightning protection material, which can accurately simulate the internal self-heating mode of the sample material during the lightning current-carrying process.

[0031] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0033] Figure 1 1 is a schematic structural diagram of a current-carrying test system for conductive lightning protection materials according to an embodiment of the present invention;

[0034] Figure 2 is a flow chart for drawing a current-carrying test of a conductive composite material according to an embodiment of the present invention;

[0035] Figure 3 is the current and voltage change data recorded during the current carrying process of the conductive material in the embodiment of the present invention;

[0036] Figure 4 is the resistivity and temperature change data of the conductive material during the current carrying process in the embodiment of the present invention;

[0037] Figure 5 This is a picture taken by a high-speed camera of the current-carrying process of the conductive material in the embodiment of the present invention.

[0038] Among them, 1. Infrared temperature probe; 2. Environmental chamber; 3. Gas valve; 4. Filter; 5. Reaction / protective gas source; 6. Vacuum pump; 7. KF vacuum electrode; 8. Programmable high-power power supply; 9. Sample electrode clamping module; 10. Current detection module; 11. Aviation plug; 12. Voltage detection module; 13. Control module; 14. Emergency stop button; 15. Data acquisition card; 16. Vacuum pressure gauge; 17. Optical glass window; 18. High-speed camera; 19. Infrared thermal imager. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0040] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0041] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0042] In the field of aerospace, lightning poses a serious threat to aircraft safety, which has prompted the widespread use of lightweight conductive composite materials as lightning protection materials in aircraft manufacturing. Conductive lightning protection materials are a type of composite lightweight conductive materials based on a polymer matrix. The matrix materials usually include epoxy resin, phenolic resin, silicone rubber, polyurethane, etc., while the conductive fillers include carbon fiber, carbon black, metal powder, etc. By selecting different matrix materials and conductive fillers and optimizing the ratio between different components, the electrical properties, mechanical properties and weight gain of conductive lightning protection materials can be coordinated and regulated, so that the efficiency of lightning protection can be improved.

[0043] During the lightning strike, the conductive lightning protection material is in a current-carrying self-heating mode, which has characteristics significantly different from the conventional external heat source heating mode such as oven, hot air gun, infrared radiation, etc.: (1) The electrical energy is directly converted into internal energy inside the material, the heat transfer is from the inside to the outside, and the heating rate is much higher than that of external heat source heating; (2) The rate of conversion of electrical energy into internal energy (i.e., Joule heat power) is affected by the real-time conductivity of the material, so the conductivity, heating and damage process of the material during the lightning strike is a two-way coupling process. (3) The conductivity of the sample in the non-current state is significantly different from that of the sample under current. Therefore, it is crucial to use the current-carrying electric Joule heating method instead of the traditional external heating method to study the evolution of the conductivity of the conductive lightning protection material during the lightning strike with temperature.

[0044] During the temperature rise process of the conductive lightning protection material due to lightning strike, when it reaches a certain temperature, the polymer matrix will undergo pyrolysis reaction, the conductive filler will undergo melting and other phase state changes, which will affect the conductive performance. Therefore, the conductive performance of the conductive lightning protection material is not only related to the temperature, but also to the degree of thermal reaction. The degree of thermal reaction of the conductive lightning protection material is a function of time and temperature. The faster the heating rate, the higher the temperature at which the thermal reaction starts. On the other hand, during the cooling stage of the lightning strike, the thermal reaction process of the conductive lightning protection material will continue. Unlike the temperature criterion, the influence of the degree of thermal reaction on the conductive performance is not reversible. Therefore, the change of the conductive performance of the conductive lightning protection material during the lightning strike requires dual criteria of temperature and degree of thermal reaction.

[0045] In the embodiment of the present invention, Figure 1 As shown, a current-carrying test system for conductive lightning protection materials includes: a discharge module, an environmental chamber 2, a sample electrode clamping module 9, a temperature measurement module, an image acquisition module, an electrical signal acquisition module and a control module 13; wherein the electrical signal acquisition module includes a current detection module 10 and a voltage detection module 12;

[0046] The sample electrode clamping module 9 is arranged in the environmental box 2, and a conductive lightning protection material is fixed on the sample electrode clamping module 9; the discharge module is connected to the control module 13 and the sample electrode clamping module 9 respectively, and the control module 13 is used to control the discharge module to simulate lightning discharge;

[0047] The temperature measurement module and the image acquisition module are co-focally arranged above the conductive lightning protection material; the electrical signal acquisition module, the temperature measurement module and the image acquisition module synchronously collect the voltage signal and the current signal of the conductive lightning protection material and the temperature and damage morphology image at the same position on the surface of the conductive lightning protection material and transmit them to the control module 13;

[0048] The control module 13 is used to construct the relationship between the current-carrying resistance of the conductive lightning protection material and the temperature and the damage state of the conductive lightning protection material at the corresponding temperature according to the synchronously received voltage signal and current signal, temperature signal and damage morphology image.

[0049] The present invention adopts a modular design concept, which not only enhances the adaptability and maintenance convenience of the system, but also enables the present invention to flexibly adapt to future technological developments and new experimental requirements.

[0050] according to Figure 1 , the outer shell of the environmental box 2 is made of stainless steel and tempered glass. The atmosphere and air pressure in the environmental box 2 are controllable. The environmental box 2 is also connected to a vacuum pressure gauge 16 for detecting the vacuum pressure information in the environmental box 2; the environmental box 2 is also connected to a reaction / protective gas source 5; a gas valve 3 is provided on the pipeline connecting the environmental box 2 and the reaction / protective gas source 5, which is used to control the amount of gas entering the environmental box 2. The environmental box 2 is also connected to the vacuum pump 6 through a filter 4, and the vacuum pump 6 is used to extract the gas in the environmental box 2. The environmental box 2 can adapt to a variety of experimental scenarios, and can test the current-carrying performance of the sample in air, protective / reaction gas, and vacuum environments. In this way, testing under different atmospheres and different air pressures can be achieved.

[0051] The side wall of the environmental box 2 is provided with several aviation plugs 11, which is convenient for connecting more electronic control devices in the box. The environmental box 2 is equipped with multiple air ports, for example, an eight-wire aviation plug is used as a signal transmission channel, and a KF vacuum electrode 7 is used as a bridge channel for large current inside and outside the box. At the same time, multiple two-wire aviation plugs are retained to facilitate the connection of other electronic devices in the environmental box.

[0052] The present invention also provides an emergency stop button 14, which provides important safety protection for experimental operation and avoids potential risks of high current and high temperature operation.

[0053] In this embodiment, the discharge module is a programmable high-power power supply 8; the programmable high-power power supply 8 can be a programmable high-power DC power supply module, which is connected in parallel and expanded by a number of small current modules through a printed circuit board, and the functions of the printed circuit board include: current input, output and on-board transmission of power control signals. In order to accurately control the step time and current size of the current applied to the sample and achieve different current increase rates, the discharge module also includes a discharge control software for synchronously controlling the power supply module, which controls the output voltage and current of the power supply module through the Modbus protocol, and can achieve a constant output of current or a linear increase at a certain time interval, and can also adjust the applied current size according to the sample temperature to achieve a constant heating rate or constant temperature test of the sample. Figure 3 The current and voltage change data recorded during the current carrying process of the conductive material in the embodiment of the present invention are given.

[0054] In other embodiments, the discharge module may also be a programmable pulse current generator, which can control the current applied to the sample to increase to thousands of amperes within a few microseconds, thereby achieving the current increase rate of a real lightning strike.

[0055] In one or more embodiments, the sample electrode clamping module 9 is placed in the environmental chamber 2 and can be flexibly replaced. There are various types, including end electrode type and center electrode type. The center electrode type is divided into direct contact type between the electrode and the sample surface and non-contact type. The non-contact type has a certain discharge gap, and can be combined with a programmable pulse current generator to realize a small artificial simulation of lightning discharge mode.

[0056] In one or more embodiments, the temperature measurement module and the image acquisition module are provided with optical glass windows 17 at positions opposite to the environmental chamber 2. The optical glass windows 17 are arranged on the top of the environmental chamber 2, and high-precision optical confocality is achieved between these optical glass windows 17.

[0057] In one or more embodiments, the temperature measurement module and the image acquisition module are respectively fixed on the optical glass window 17 at a preset position through corresponding sleeves.

[0058] In some specific embodiments, a rotatable component is provided in the sleeve for fine-tuning the temperature measurement module and the image acquisition module to achieve multi-point confocality, that is, the extension lines of multiple aperture axes converge at the same focus in space.

[0059] In the specific implementation process, the temperature measurement module is composed of at least one infrared temperature measurement probe 1 and an infrared thermal imager 19, which is used to simultaneously measure the high-frequency temperature point data and low-frequency temperature distribution data of the conductive lightning protection material. The measured temperature range is extremely wide (-25 to 3000°C), and the influence of thermal discoloration, pyrolysis and combustion smoke on the accuracy of the data can be eliminated.

[0060] The control module 13 is used to splice the temperature signals transmitted by the infrared temperature measuring probe and the infrared thermal imager to obtain a complete temperature curve during the test process.

[0061] Specifically, in the control module 13, during the process of splicing the temperature signals transmitted by the infrared temperature measuring probe and the infrared thermal imager, the temperature data with the same temperature slope and a temperature difference less than the set temperature in the overlapping interval is selected as the overlapping point of the temperature measured by the infrared temperature measuring probe and the infrared thermal imager, and the temperature signals transmitted by the infrared temperature measuring probe and the infrared thermal imager are spliced ​​to obtain a complete temperature curve during the test process.

[0062] In the specific implementation process, the control module 13 is used to calculate the resistance of the conductive lightning protection material at the corresponding test time point according to the synchronously received voltage signal and current signal, and then draw the conductive composite material current-carrying resistance-temperature relationship curve according to the temperature signal at the corresponding test time point. Figure 4 The resistivity and temperature variation data of the conductive material during the current carrying process in the embodiment of the present invention are given.

[0063] In the embodiment of the present invention, the image acquisition module may be implemented by a high-speed camera 18 . Figure 5 The photographs taken by a high-speed camera of the current-carrying process of the conductive material in the embodiment of the present invention are given.

[0064] The environmental chamber 2 integrates temperature and motion acquisition windows through confocal technology, ensuring that multiple infrared temperature measuring devices and high-speed cameras 18 can measure and record the same position of the sample from multiple angles, realizing real-time monitoring of the temperature and damage morphology at the same position on the sample surface.

[0065] The control module 13 integrates the data acquisition card 15, analog signal transmitter, serial port expansion card, USB HUB and other functional modules, realizing a one-line connection from control to equipment. The control module 13 also integrates a 24V power supply to power external sensors, thermal imagers and other equipment, and uses a 24V to 5V isolated power supply module to power acquisition cards, transmitters and other acquisition equipment, avoiding the signal and power supply sharing the same ground, and improving the stability and reliability of data acquisition. In addition, the control module 13 can also adjust the infrared emissivity of the temperature measuring probe according to the collected sample temperature to improve the temperature measurement accuracy of the temperature measuring probe.

[0066] In one or more embodiments, a trained image classification model is pre-stored in the control module 13, and the damage degree of the damage morphology image is classified based on the image classification model to obtain the corresponding damage degree.

[0067] It should be noted here that the image classification model is an existing neural network structure, which will not be described in detail here.

[0068] Among them, the cross-scale finite element simulation model of the current-carrying process of the conductive lightning protection material includes the mesoscopic scale current-carrying model of the conductive lightning protection material and the current-carrying macroscopic model of the conductive lightning protection material;

[0069] The mesoscopic current-carrying model of the conductive lightning protection material needs to reflect the shape, overlap and spatial distribution of the conductive filler in the resin matrix (which can be obtained through in-situ Micro-CT and other characterization methods). In the mesoscopic modeling process, the influence of the coating temperature and thermal ablation on the conductive properties during the lightning strike process needs to be considered: the influence of temperature on the conductive properties is further decomposed into factors such as the influence of temperature on the intrinsic conductive properties of the conductive filler and the influence of the thermal mismatch between the conductive filler and the matrix on the conductive path; the influence of thermal ablation on the conductive properties is further decomposed into the influence of multiple physical and chemical damage processes such as thermal decomposition of the resin matrix and melting of the metal filler on the conductive path. Then, these influencing factors are analyzed by orthogonal simulation methods to reveal the evolution mechanism of the conductive properties of the conductive composite material from the mesoscopic scale.

[0070] The current-carrying macroscopic model of conductive lightning protection materials applies a current load consistent with the experiment (different current increase rates, different electrode types), inputs the conductivity evolution obtained by actual measurement and mesoscopic scale current-carrying simulation, simulates the voltage and temperature distribution of the sample, and compares it with the actual measured voltage and temperature of the current-carrying to verify and correct the conductivity evolution model.

[0071] In one or more embodiments, a testing method based on a current-carrying testing system for conductive lightning protection materials includes:

[0072] Fix the conductive lightning protection material on the sample electrode clamping module, and adjust the atmosphere and air pressure in the environmental box to the preset environment;

[0073] The control discharge module simulates lightning discharge and acts on the conductive lightning protection material;

[0074] Synchronously collect the voltage signal and current signal of the conductive lightning protection material and the temperature and damage morphology image at the same position on the surface of the conductive lightning protection material;

[0075] According to the synchronously received voltage signal, current signal, temperature signal and damage morphology image, the relationship between the current-carrying resistance of the conductive lightning protection material and the temperature and the damage state of the conductive lightning protection material at the corresponding temperature are constructed.

[0076] Take the example of conductive lightning protection material using blended modified silicone rubber:

[0077] like Figure 2 As shown in the figure, the process of drawing the current-carrying resistance-temperature relationship curve of the conductive lightning protection material includes:

[0078] (1) Select an environmental box of appropriate size. In this embodiment, the internal environmental size of the environmental box is 400 mm × 400 mm × 400 mm. The box is provided with KF25 electrodes and an eight-wire aviation plug, and a filter is installed outside the box.

[0079] (2) In this embodiment, a highly sensitive infrared temperature measuring probe capable of detecting medium and high temperature ranges and a programmable high-power power supply with a maximum power of 19200W, a maximum output current of 240A, and a maximum output voltage of 80V are selected.

[0080] (3) Close all external air valves and optical glass windows of the environmental chamber, start the vacuum system, and conduct a tightness check on the environmental chamber to ensure that the chamber is intact and there is no leakage.

[0081] (4) Cut the blended modified conductive silicone rubber material into samples of predetermined size (25 mm × 35 mm × 3 mm), ensuring that the size and shape of each sample are consistent.

[0082] (5) Conductive silver glue is used to stick one end of the longer electronic copper foil to the conductive surface of one end of the coated sample, and then the sample is placed on an alumina honeycomb ceramic plate. Finally, the electronic copper foil strip is clamped into the movable copper electrode and fixedly connected to the Joule heating main circuit.

[0083] (6) Connect the positive and negative electrodes at both ends of the sample to the positive and negative electrodes of KF25 on the back of the environmental chamber.

[0084] (7) The data acquisition system used in this embodiment includes a 0-30V high-precision voltmeter, a 0-80V high-precision voltmeter, a 0.1%-level precision shunt, a 4-20mA to 0-10V converter, and a 0-10V data acquisition card.

[0085] (8) The data acquisition card used in this embodiment has a maximum sampling frequency of 200K and can synchronously output temperature data, current data and voltage data.

[0086] (9) Connect the shunt in series to the Joule heating main circuit and connect a 0-30V high-precision voltmeter to both ends of the shunt. Record the voltage across the shunt and calculate the current in the main circuit using Ohm's law.

[0087] (10) Use the terminal block to lead out two voltage test wires at both ends of the sample, connect them to a 0-80V high-precision voltmeter through the aviation plug on the box and the aviation socket.

[0088] (11) In this embodiment, two infrared temperature measuring probes are used. In the medium temperature range, a coaxial infrared temperature measuring probe with a wavelength of 1.8-2.7 μm and a temperature measuring range of 50-500°C is used. In the high temperature range, a coaxial infrared temperature measuring probe with a wavelength of 1.8-2.7 μm and a temperature measuring range of 300-1800°C is used.

[0089] (12) Adjust the focal length of the infrared temperature measuring probe to ensure that the temperature changes in the 15 mm diameter area at the center of the sample can be covered and accurately monitored.

[0090] (13) When recording temperature data and there is overlap in the collected temperature intervals, the temperature measured by the infrared temperature measuring probe with the higher temperature measuring interval shall prevail.

[0091] (14) In this embodiment, the motion acquisition window uses a 1.6 million pixel black and white high-speed camera with a frame rate of 249fps and a 5 million pixel color high-speed camera with a frame rate of 60fps to record the color changes and damage changes on the sample surface. At the same time, a 0-2000℃ infrared thermal imager is used to record the distribution of the sample temperature field during the current carrying process.

[0092] (15) Replace the high-speed camera lens with a suitable focal length. In this embodiment, all high-speed cameras use a 25 mm lens to ensure that the entire surface of the sample can be observed.

[0093] (16) Install the infrared thermal imager on the germanium glass window dedicated to the infrared thermal imager on the environmental chamber, and adjust the focus and focal length to the center of the sample.

[0094] (17) Adjust the valve opening and closing in the environmental chamber, start the vacuum system, and adjust the inside of the environmental chamber to a negative pressure state (-100.4Kpa).

[0095] (18) Synchronously turn on the data acquisition card, high-speed camera and infrared thermal imager.

[0096] (19) A predetermined current is applied to the sample through a programmable high-power power supply, and the magnitude, change trend, and duration of the current are adjusted.

[0097] (20) After the application of the predetermined current ends, the programmable high-power power supply, the data acquisition card, the high-speed camera and the infrared thermal imager are synchronously turned off.

[0098] (21) The synchronous data of the temperature, current, and voltage of the sample recorded by the data acquisition card are exported, and the actual temperature of the sample, the actual current passing through the sample, and the actual voltage at both ends of the sample are calculated using the data output by the data acquisition card. The current and voltage are substituted into Ohm's law to calculate the resistance value of the sample at different temperatures.

[0099] (22) Repeat the above experiment and obtain multiple sets of data. The measured resistance of the sample is unified into the resistivity of the sample according to the size of the sample.

[0100] (23) The synchronously recorded temperature data is synchronously correlated with the calculated resistivity data to accurately obtain the resistivity-temperature relationship of the sample.

[0101] (24) After the experiment is completed, turn off all power supplies. Carefully check the status of the samples and equipment to ensure safe shutdown.

[0102] (25) The experimental data were processed, the resistivity-temperature curve was plotted, and the response characteristics of the blended modified silicone rubber were analyzed.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A current-carrying test system for conductive lightning protection materials, characterized in that: include: Discharge module, environmental chamber, sample electrode clamping module, temperature measurement module, image acquisition module, electrical signal acquisition module and control module; The sample electrode clamping module is arranged in the environmental chamber, and a conductive lightning protection material is fixed on the sample electrode clamping module; the discharge module is connected to the control module and the sample electrode clamping module respectively, and the control module is used to control the discharge module to simulate lightning discharge; The temperature measurement module and the image acquisition module are co-focally arranged above the conductive lightning protection material; the electrical signal acquisition module, the temperature measurement module and the image acquisition module synchronously collect the voltage signal and the current signal of the conductive lightning protection material and the temperature and damage morphology image at the same position on the surface of the conductive lightning protection material and transmit them to the control module; The temperature measurement module and the image acquisition module are respectively fixed on the optical glass window at a preset position through corresponding sleeves; A rotatable component is provided in the sleeve for fine-tuning the temperature measurement module and the image acquisition module to achieve multi-point confocal; The temperature measurement module is composed of at least one infrared temperature measurement probe and an infrared thermal imager, and is used to simultaneously measure the high-frequency temperature point data and low-frequency temperature distribution data of the conductive lightning protection material; The control module is used to splice the temperature signals transmitted by the infrared temperature measuring probe and the infrared thermal imager to obtain a complete temperature curve during the test; In the process of splicing the temperature signals transmitted by the infrared temperature measuring probe and the infrared thermal imager, the temperature slope in the overlapping interval is the same and the temperature difference is less than the set temperature data, which is selected as the coincidence point of the temperature measured by the infrared temperature measuring probe and the infrared thermal imager, and the temperature signals transmitted by the infrared temperature measuring probe and the infrared thermal imager are spliced ​​to obtain a complete temperature curve in the test process; The control module is used to construct the relationship between the current-carrying resistance of the conductive lightning protection material and the temperature and the damage state of the conductive lightning protection material at the corresponding temperature based on the synchronously received voltage signal and current signal, temperature signal and damage morphology image.

2. The conductive lightning protection material current-carrying test system according to claim 1, characterized in that: Optical glass windows are arranged at positions where the temperature measurement module and the image acquisition module are opposite to the environmental chamber.

3. The conductive lightning protection material current-carrying test system according to claim 1, characterized in that: The control module is used to calculate the resistance of the conductive lightning protection material at the corresponding test time point according to the synchronously received voltage signal and current signal, and then draw a conductive composite material current-carrying resistance-temperature relationship curve according to the temperature signal at the corresponding test time point.

4. The conductive lightning protection material current-carrying test system according to claim 1, characterized in that: A trained image classification model is pre-stored in the control module, and the damage degree of the damage morphology image is classified based on the image classification model to obtain the corresponding damage degree.

5. The conductive lightning protection material current-carrying test system according to claim 1, characterized in that: The atmosphere and air pressure in the environmental box are both controllable.

6. A testing method based on the current-carrying testing system for conductive lightning protection materials according to any one of claims 1 to 5, characterized in that: include: Fix the conductive lightning protection material on the sample electrode clamping module, and adjust the atmosphere and air pressure in the environmental box to the preset environment; The control discharge module simulates lightning discharge and acts on the conductive lightning protection material; Synchronously collect the voltage signal and current signal of the conductive lightning protection material and the temperature and damage morphology image at the same position on the surface of the conductive lightning protection material; According to the synchronously received voltage signal, current signal, temperature signal and damage morphology image, the relationship between the current-carrying resistance of the conductive lightning protection material and the temperature and the damage state of the conductive lightning protection material at the corresponding temperature are constructed.

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