Rapid and efficient nondestructive inspection method and system for resin-based composite material

Abstract

The invention discloses a rapid and efficient nondestructive inspection method and system for a resin-based composite material, and the method comprises the following steps: adding magnetic powder with a magnetostrictive effect into a resin formula of the resin-based composite material to obtain a prefabricated composite material resin raw material; obtaining a to-be-tested resin finished product based on production of the prefabricated composite material; placing the coil inductor on the surface of a resin finished product to be measured, applying low-voltage alternating current to the coil inductor, and measuring and recording the inductance reading of each area in an undamaged state to obtain a magnetic signal reference map; regularly detecting the surface of the used to-be-detected resin finished product to obtain a magnetic signal detection map of the to-be-detected resin finished product; and carrying out difference analysis on the magnetic signal detection map and the magnetic signal reference map, and determining the internal structure change and damage condition of the resin finished product to be detected. The method disclosed by the invention is used for carrying out efficient and rapid nondestructive inspection on the resin-based composite material based on the magnetostrictive effect, and has multiple advantages of high sensitivity, low detection cost, convenience, rapidness and the like.

Description

Technical Field

[0001] The invention relates to the technical field of nondestructive testing of composite materials, and in particular to a fast and efficient nondestructive testing method and system for resin-based composite materials. Background Art

[0002] Resin-based composites are composite materials composed of resin (as matrix material) and reinforcement materials (such as fibers or particles). Resin is a polymer with good adhesion and formability, which can firmly bind the reinforcement materials together. It is widely used in aerospace, automotive, construction and other fields. It is very important to monitor or detect resin-based composites to detect structural failures as early as possible. Regular monitoring of composite materials can effectively evaluate the health status of the material and help take preventive measures in time to avoid material damage.

[0003] There are many methods for detecting damage in composite materials, including contact methods and non-contact methods. Non-contact methods include visual inspection, radiography and ultrasonic inspection. Visual inspection has low accuracy and requires a lot of training for relevant personnel. The accuracy cannot be guaranteed in some high-demand places. Radiographic and ultrasonic inspections require the use of high-energy mechanical waves or electromagnetic waves, which will affect the life and structural health of the material. They often require the use of bulky equipment. When used for detection, the probe is not convenient to enter a small space, the detection site is also limited, and the equipment cannot be carried with you. If used for monitoring, the volume and weight will greatly increase the burden on the object being detected. Contact methods include eddy currents, piezoelectric materials and optical fibers. Although technologies such as piezoelectric sensors and optical fibers have been proven to detect different damages in laboratory environments, their use on aircraft is limited because installing sensors and wires on composite parts will generate additional weight, which may cause further damage to the aircraft.

[0004] Therefore, it is necessary to propose a fast and efficient non-destructive testing method and system for resin-based composite materials, which can simplify the operating steps of composite material testing, thereby reducing testing costs, improving testing efficiency, and expanding the scope of application, providing a fast and efficient solution for quality testing of resin-based composite materials. Summary of the invention

[0005] The present invention provides a fast and efficient nondestructive flaw detection method and system for resin-based composite materials, which are used to solve the technical problems of high operation complexity, high efficiency and low cost in the existing nondestructive flaw detection of damage in resin-based composite materials.

[0006] In order to solve the above problems, the present invention provides a fast and efficient non-destructive flaw detection method for resin-based composite materials, comprising:

[0007] Adding magnetic powder with magnetostrictive effect to the resin formula of the resin-based composite material to obtain a prefabricated composite material;

[0008] Producing finished products based on the prefabricated composite material to obtain a resin finished product to be tested;

[0009] Placing a coil inductor on the surface of the resin product to be tested, applying low-voltage alternating current to the coil inductor, measuring and recording the inductance readings of each area of ​​the resin product to be tested in an undamaged state, and obtaining a magnetic signal reference map of the resin product to be tested;

[0010] Regularly placing a coil inductor on the surface of the used finished resin product to be tested, applying low-voltage alternating current to the coil inductor, recording the inductance readings of various areas of the used finished resin product to be tested, and obtaining a magnetic signal detection map of the finished resin product to be tested;

[0011] A difference analysis is performed on the magnetic signal detection map and the magnetic signal reference map, and the structural changes and damage conditions inside the resin finished product to be tested are determined based on the analysis results.

[0012] Further, measuring and recording the inductance readings of each area of ​​the resin product to be tested in an undamaged state to obtain a magnetic signal reference map of the resin product to be tested, including:

[0013] The length and width of the surface of the resin finished product to be tested are used as the abscissa and ordinate of the magnetic signal reference map respectively;

[0014] The inductance value of the coil inductor corresponding to each coordinate position of the finished product is recorded to obtain a magnetic signal reference map reflecting the magnetic field strength of each area of ​​the resin finished product to be tested in an undamaged state.

[0015] Furthermore, the magnetic signal reference map and the magnetic signal detection map include: area division lines obtained by connecting points with the same inductance value, and different colors for distinguishing the inductance values ​​of each area.

[0016] Further, the structural changes and damage conditions inside the resin finished product to be tested are determined according to the analysis results, including:

[0017] When the difference between the first magnetic signal detection map corresponding to the first plane of the tested resin finished product and the corresponding first magnetic signal reference map is greater than a preset range, and the difference between the second magnetic signal detection map corresponding to the second plane of the tested resin finished product and the corresponding second magnetic signal reference map is less than a preset range, it is determined that the tested resin finished product is scratched;

[0018] When the difference between the first magnetic signal detection map corresponding to the first plane of the finished resin product to be tested and the corresponding first magnetic signal reference map is greater than a preset range, and the difference between the second magnetic signal detection map corresponding to the second plane of the finished resin product to be tested and the corresponding second magnetic signal reference map is greater than or equal to the preset range, it is determined that the finished resin product to be tested is subjected to impact damage.

[0019] Furthermore, the magnetic powder having magnetostrictive effect includes one or more kinds.

[0020] Furthermore, the particle size of the magnetic powder is micrometer-level or nanometer-level.

[0021] Furthermore, the types of magnetic powder having magnetostrictive effect include at least: iron-nickel alloy, dysprosium-iron alloy, nickel metal, cobalt metal, terbium-dysprosium-iron alloy and ferrite.

[0022] Furthermore, the production of finished products based on the prefabricated composite material to obtain the resin finished product to be tested includes:

[0023] The prefabricated composite material is subjected to a prepreg layering process, a resin transfer molding process and a compression molding process to obtain a resin finished product to be tested.

[0024] The present invention also provides a fast and efficient nondestructive flaw detection system for resin-based composite materials, which is used to implement the fast and efficient nondestructive flaw detection method for resin-based composite materials described in any of the above technical solutions, comprising an inductor device and an analyzer connected to each other;

[0025] The inductor device is made by winding a coil along the circumferential direction of a ring-shaped permanent magnet, and is used to sense the magnetic field changes on the surface of the resin finished product to be tested;

[0026] The analyzer is used to apply low voltage alternating current to the coil of the inductor device so that the external magnetic field forms a reverse voltage inside the coil, and obtain the inductance reading of the surface of the resin finished product to be tested to generate a magnetic signal map.

[0027] Furthermore, the model of the analyzer is AtlasLCR45.

[0028] Compared with the prior art, the beneficial effects of the present invention include: by adding magnetic powder with magnetostrictive effect to the resin formula, the present invention can significantly enhance the response of the material to the external magnetic field, making the detection of internal defects more sensitive and reliable. By applying low-voltage alternating current to the coil inductor, the inductance reading can be quickly obtained. By performing differential analysis on the magnetic signal detection map and the reference map, the structural changes and damage inside the material can be quickly identified, thereby achieving accurate fault location and evaluation, which can effectively reduce the time and manpower required in traditional detection methods and improve detection efficiency. It is suitable for the detection of various resin-based composite materials, including applications in aerospace, automobiles, construction and other fields, has strong applicability and universality, and realizes detection through non-destructive technical means, timely discovers potential material damage, reduces accidents and maintenance costs caused by untimely detection, and reduces overall maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of a process flow of a fast and efficient non-destructive flaw detection method for resin-based composite materials provided by the present invention;

[0030] Figure 2 A schematic diagram of a magnetic signal detection map of a resin finished product to be tested provided by the present invention;

[0031] Figure 3 A schematic diagram of the application of a fast and efficient nondestructive flaw detection system for resin-based composite materials provided by the present invention. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0033] Before introducing the embodiments of the present invention, relevant technical terms in this application are explained first.

[0034] Magnetostrictive effect: The length and volume of a magnetic material will change slightly due to a change in its magnetization state. Conversely, a change in the physical size of a magnetic material will cause a change in its magnetization state.

[0035] This embodiment provides a fast and efficient nondestructive flaw detection method for resin-based composite materials. Magnetic powder with magnetostrictive effect is added to the resin formula of the resin-based composite material. After the magnetization state of the powder changes, the magnetic field around the magnetic material changes. The change in the magnetic field is detected by an inductor coil. The stress of the magnetic material and the stress change can be judged by the change in the magnetic field, thereby judging whether the composite material is damaged.

[0036] like Figure 1As shown, Figure 1 : is a schematic diagram of the process of the fast and efficient non-destructive flaw detection method of resin-based composite materials, the method comprising:

[0037] Step S101: adding magnetic powder having a magnetostrictive effect to a resin formula of a resin-based composite material to obtain a prefabricated composite material;

[0038] Step S102: producing a finished product based on the prefabricated composite material to obtain a resin finished product to be tested;

[0039] Step S103: placing a coil inductor on the surface of the resin product to be tested, applying low voltage alternating current to the coil inductor, measuring and recording the inductance readings of each area of ​​the resin product to be tested in an undamaged state, and obtaining a magnetic signal reference map of the resin product to be tested;

[0040] Step S104: regularly placing the coil inductor on the surface of the used resin product to be tested, applying low-voltage alternating current to the coil inductor, recording the inductance readings of each area of ​​the used resin product to be tested, and obtaining a magnetic signal detection map of the resin product to be tested;

[0041] Step S105: performing difference analysis on the magnetic signal detection map and the magnetic signal reference map, and determining the structural changes and damage conditions inside the resin finished product to be tested according to the analysis results.

[0042] The fast and efficient nondestructive flaw detection method for resin-based composite materials provided in this embodiment can significantly enhance the response of the material to the external magnetic field by adding magnetic powder with magnetostrictive effect to the resin formula, making the detection of internal defects more sensitive and reliable. By applying low-voltage alternating current to the coil inductor, the inductance reading can be quickly obtained. By performing differential analysis on the magnetic signal detection map and the reference map, the structural changes and damage inside the material can be quickly identified, thereby achieving accurate fault assessment and judgment. The method of this embodiment reduces the time and manpower required in traditional detection methods, improves detection efficiency, and is suitable for the detection of various resin-based composite materials, including applications in aerospace, automobiles, construction and other fields. It has strong applicability and universality, and realizes detection through non-destructive technical means, timely discovers potential material damage, reduces accidents and maintenance costs caused by untimely detection, and reduces overall maintenance costs.

[0043] As a preferred embodiment, in step S101, the magnetic powder with magnetostrictive effect includes one or more magnetic powders with magnetostrictive effect that can be added to the composite resin matrix or the surface of the fiber reinforcement, and the amount of the magnetic powder is about 1%-3% of the mass of the resin body. Such powders include but are not limited to: iron-nickel alloy, dysprosium-iron alloy, nickel metal, cobalt metal, terbium-dysprosium-iron alloy, ferrite and other materials. The particle size of the powder is micrometer or nanometer.

[0044] It should be noted that to ensure the successful application of the magnetostrictive effect, these materials need to be made into micron- or nano-scale particles and evenly dispersed inside the object to be detected; the particles are dispersed during the mixing and configuration of the resin. As part of the resin formula additive, the particles can improve the utilization efficiency of the magnetostrictive effect of the material, and can also enhance the overall performance and detection capabilities of the composite material, providing a more reliable basis for subsequent non-destructive testing. For equipment such as ships, aircraft, and spacecraft, induction coils can be arranged at key stress-bearing structures using resin-based composite materials as structural parts to monitor the structural condition of the equipment. For products that have been implanted with magnetostrictive particles, the damage of the product can be judged by comparing the changes in the magnetization mapping map before and after the force and before and after work. It is especially suitable for damage that is invisible to the naked eye and for detecting potential material damage in advance.

[0045] As a preferred embodiment, in step S102, the production of finished products based on the prefabricated composite material to obtain a resin finished product to be tested includes:

[0046] The prefabricated composite material is subjected to prepreg, resin transfer molding and composite material forming processes to obtain a finished resin product to be tested.

[0047] It should be noted that in the traditional system using magnetostrictive effect, the magnetic material needs to be pasted on the surface of the object to be measured, which requires a large amount of material, which will greatly increase the weight of the object to be measured and is easy to peel off. The method of the present invention makes the magnetic material into small particles and disperses them into the resin, and mixes with the resin when the resin is not solidified. When the resin is solidified during the processing, the small magnetic particles will form a whole with the resin-based composite material, which has a much smaller impact on weight than other forms, and the sensing effect is sensitive.

[0048] As a preferred embodiment, in step S103, a coil inductor is placed on the surface of a composite material containing magnetic particles. The magnetic particles in the composite material will form a magnetic field, and the coil will be affected by the magnetic field. After the analyzer is turned on, the analyzer applies low-voltage alternating current to the coil. Due to the inductance effect, the external magnetic field will form a reverse voltage inside the coil. When the composite material is not subjected to force, the magnetic field will not change. Therefore, the reverse voltage is approximately a constant value, which is used as the reference inductance value when the composite material is not subjected to force and is not damaged.

[0049] Specifically, the surface of the composite material is evenly divided into several blocks of different shapes and sizes, and each block is measured once. When the divided area is sufficiently differentiated, a magnetic signal map covering the surface of the material can be formed, and the signal is the inductance reading.

[0050] As a specific embodiment, measuring and recording the inductance readings of each area of ​​the resin product to be tested in an undamaged state to obtain a magnetic signal reference map of the resin product to be tested includes:

[0051] The length and width of the surface of the resin finished product to be tested are used as the abscissa and ordinate of the magnetic signal reference map respectively;

[0052] The magnetic flux density reading of the coil inductor corresponding to each coordinate position of the finished product is recorded to obtain a magnetic signal reference map reflecting the magnetic field strength of each area of ​​the resin finished product to be tested in an undamaged state.

[0053] In some embodiments, the magnetic signal reference map and the magnetic signal detection map include: area division lines obtained by connecting points with the same inductance value, and different colors for distinguishing the inductance values ​​of each area.

[0054] Specifically, the color depth or color corresponds to the reading of the LCRmeter, which is the quantitative value of the electric field at the location of the coil, used to calculate the magnetic flux density. The horizontal and vertical coordinates are the position coordinates, the two-dimensional spatial position of the sample after flattening, which can accurately monitor the force of every part of the entire workpiece in real time.

[0055] When the composite material is subjected to force, the magnetic particles are squeezed, so the magnetic field in the area changes due to the magnetostrictive effect. At this time, the reverse voltage generated inside the inductor coil also changes, so the change in inductance at that position can be read on the analyzer. When the object being tested is deformed or damaged due to force, the same method can be used to scan and test again to obtain a picture with changed details.

[0056] We connect points with the same inductance value to get the area division lines, and the different colors to distinguish the inductance values ​​of each area. In other words, if the inductance value is regarded as the altitude, the inductance reading "contour map" of the composite material can be obtained when the area is sufficiently differentiated. Figure 2 As shown, Figure 2 The change of magnetization mapping after 1.54J impact is shown. From left to right, it corresponds to the 1st, 2nd and 3rd impact. The red cross mark indicates the impact position, and the scale at the bottom indicates the change of the sensor's magnetization reading (Tesla). By comparing the difference between the before and after graphics (magnetization mapping map), we can understand the force deformation or damage of the object.

[0057] from Figure 2 It can be clearly seen that as the degree of damage increases, the redder the color, the higher the reading. The degree of damage can be characterized by changes in readings and image color.

[0058] As a specific embodiment, determining the structural changes and damage conditions inside the resin finished product to be tested according to the analysis results includes:

[0059] When the difference between the first magnetic signal detection map corresponding to the first plane of the tested resin finished product and the corresponding first magnetic signal reference map is greater than a preset range, and the difference between the second magnetic signal detection map corresponding to the second plane of the tested resin finished product and the corresponding second magnetic signal reference map is less than a preset range, it is determined that the tested resin finished product is scratched;

[0060] When the difference between the first magnetic signal detection map corresponding to the first plane of the finished resin product to be tested and the corresponding first magnetic signal reference map is greater than a preset range, and the difference between the second magnetic signal detection map corresponding to the second plane of the finished resin product to be tested and the corresponding second magnetic signal reference map is greater than or equal to the preset range, it is determined that the finished resin product to be tested is subjected to impact damage.

[0061] For example, when magnetic powder is only dispersed on the surface of both sides of the plate, if two magnetic mapping maps of both sides of the plate are read and made separately during the test, if the map of one side changes significantly, but the other map does not change much, then the plate may be damaged on one side due to scratches; if the plate is damaged by impact, then both maps should have obvious reading changes at the same position.

[0062] Therefore, by comparing the changes in the magnetization map of the object before and after the impact, the changes in the object can be intuitively distinguished. The magnetization map data is like a map and contour lines. Even an unskilled observer can easily distinguish the difference between the data and distinguish the degree of damage by color.

[0063] In some embodiments, inductor coils are evenly pasted on the surface of the same object, and each inductor coil is connected to an independent LCR to form a separate circuit. All LCRs send data back to the same computer for processing. The data sent back includes inductor reading information and the spatial position of the corresponding coil. When the computer reads the readings of all coils at the same time, an instantaneous magnetization mapping map can be formed, which accumulates over time to form a string of real-time monitoring data.

[0064] The embodiment of the present invention also provides a fast and efficient non-destructive flaw detection system for resin-based composite materials, which is used to implement the fast and efficient non-destructive flaw detection method for resin-based composite materials described in the above technical solution, including an inductor device and an analyzer connected to each other;

[0065] The inductor device is made by winding a coil along the circumferential direction of a ring-shaped permanent magnet, and is used to sense the magnetic field changes on the surface of the resin finished product to be tested;

[0066] The analyzer is used to apply low voltage alternating current to the coil of the inductor device so that the external magnetic field forms a reverse voltage inside the coil, and obtain the inductance reading of the surface of the resin finished product to be tested to generate a magnetic signal map.

[0067] The application diagram of the above system is as follows Figure 3 As shown. This system can be used to conveniently, quickly and efficiently detect the stress or structural damage of resin-based composite materials or monitor them in real time; the detector used is small and simple and can be operated by hand. In addition, the detector probe is a coil that can penetrate into a very small area. Regardless of the size and shape of the object to be tested, it can be fully monitored without bringing too much volume and weight burden, and there is no need to place large equipment around the object to be tested, which greatly improves the efficiency of non-destructive testing and reduces the cost of testing, making it suitable for large-scale promotion and application.

[0068] As a preferred embodiment, the model of the analyzer is AtlasLCR45.

[0069] In actual use, a 112-turn pickup coil connected to an Atlas LCR45 analyzer can be used to measure the inductance of a composite material after it is stressed or damaged. The inductor includes a coil and a permanent magnet. The coil is a good conductor. The coil is wound around a ring-shaped permanent magnet to make an inductor device. The coil is wound along the circumference of the ring magnet. The ring-shaped permanent magnet in the middle is used to enhance the induction. The analyzer and the coil are connected to receive and process the electrical signal in the coil into a digital signal or an analog signal.

[0070] The fast and efficient nondestructive flaw detection method and system for resin-based composite materials provided by the present invention can significantly enhance the response of the material to the external magnetic field by adding magnetic powder with magnetostrictive effect to the resin formula, making the detection of internal defects more sensitive and reliable. By applying low-voltage alternating current to the coil inductor, the inductance reading can be quickly obtained. By performing differential analysis on the magnetic signal detection map and the reference map, the structural changes and damage inside the material can be quickly identified, thereby achieving accurate fault location and evaluation. The method of the present invention reduces the time and manpower required in traditional detection methods and improves detection efficiency. It is suitable for the detection of various resin-based composite materials, including applications in the fields of aerospace, automobiles, and construction. It has strong applicability and universality, and realizes detection through non-destructive technical means, timely discovering potential material damage, reducing accidents and maintenance costs caused by untimely detection, and reducing overall maintenance costs.

[0071] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A fast and efficient nondestructive flaw detection method for resin-based composite materials, characterized in that: include: Adding magnetic powder with magnetostrictive effect to the resin formula of the resin-based composite material to obtain a prefabricated composite material; Producing finished products based on the prefabricated composite material to obtain a resin finished product to be tested; Placing a coil inductor on the surface of the resin product to be tested, applying low-voltage alternating current to the coil inductor, measuring and recording the inductance readings of each area of ​​the resin product to be tested in an undamaged state, and obtaining a magnetic signal reference map of the resin product to be tested; Regularly placing a coil inductor on the surface of the used finished resin product to be tested, applying low-voltage alternating current to the coil inductor, recording the inductance readings of various areas of the used finished resin product to be tested, and obtaining a magnetic signal detection map of the finished resin product to be tested; A difference analysis is performed on the magnetic signal detection map and the magnetic signal reference map, and the structural changes and damage conditions inside the resin finished product to be tested are determined based on the analysis results.

2. The fast and efficient nondestructive flaw detection method for resin-based composite materials according to claim 1 is characterized in that: Measuring and recording the inductance readings of each area of ​​the resin product to be tested in an undamaged state to obtain a magnetic signal reference map of the resin product to be tested, including: The length and width of the surface of the resin finished product to be tested are used as the abscissa and ordinate of the magnetic signal reference map respectively; The inductance value of the coil inductor corresponding to each coordinate position of the finished product is recorded to obtain a magnetic signal reference map reflecting the magnetic field strength of each area of ​​the resin finished product to be tested in an undamaged state.

3. The fast and efficient nondestructive flaw detection method for resin-based composite materials according to claim 1 is characterized in that: The magnetic signal reference map and the magnetic signal detection map include: area division lines obtained by connecting points with the same inductance value, and different colors for distinguishing the inductance values ​​of each area.

4. The fast and efficient nondestructive flaw detection method for resin-based composite materials according to claim 1 is characterized in that: Determine the structural changes and damage conditions inside the resin finished product to be tested based on the analysis results, including: When the difference between the first magnetic signal detection map corresponding to the first plane of the tested resin finished product and the corresponding first magnetic signal reference map is greater than a preset range, and the difference between the second magnetic signal detection map corresponding to the second plane of the tested resin finished product and the corresponding second magnetic signal reference map is less than a preset range, it is determined that the tested resin finished product is scratched; When the difference between the first magnetic signal detection map corresponding to the first plane of the finished resin product to be tested and the corresponding first magnetic signal reference map is greater than a preset range, and the difference between the second magnetic signal detection map corresponding to the second plane of the finished resin product to be tested and the corresponding second magnetic signal reference map is greater than or equal to the preset range, it is determined that the finished resin product to be tested is subjected to impact damage.

5. The fast and efficient nondestructive flaw detection method for resin-based composite materials according to claim 1 is characterized in that: The magnetic powder having magnetostrictive effect includes one or more kinds of magnetic powder.

6. The fast and efficient nondestructive flaw detection method for resin-based composite materials according to claim 5, characterized in that: The particle size of the magnetic powder is micrometer-level or nanometer-level.

7. The fast and efficient nondestructive flaw detection method for resin-based composite materials according to claim 5, characterized in that: The types of magnetic powder with magnetostrictive effect include at least: iron-nickel alloy, dysprosium-iron alloy, nickel metal, cobalt metal, terbium-dysprosium-iron alloy and ferrite.

8. The fast and efficient nondestructive flaw detection method for resin-based composite materials according to claim 1, characterized in that: The method of producing a finished product based on the prefabricated composite material to obtain a resin finished product to be tested comprises: The prefabricated composite material is subjected to prepreg layering or resin transfer molding to obtain a finished resin product to be tested.

9. A fast and efficient nondestructive flaw detection system for resin-based composite materials, characterized in that: A method for realizing a fast and efficient nondestructive flaw detection of a resin-based composite material as claimed in claims 1 to 8, comprising an inductor device and an analyzer connected to each other; The inductor device is made by winding a coil along the circumferential direction of a ring-shaped permanent magnet, and is used to sense the magnetic field changes on the surface of the resin finished product to be tested; The analyzer is used to apply low voltage alternating current to the coil of the inductor device so that the external magnetic field forms a reverse voltage inside the coil, and obtain the inductance reading of the surface of the resin finished product to be tested to generate a magnetic signal map.

10. The fast and efficient nondestructive flaw detection system for resin-based composite materials according to claim 9 is characterized in that: The model of the analyzer is Atlas LCR45.

Images