Method for measuring internal displacement of composite material by using auxiliary particles

Abstract

The invention provides a method for measuring the internal displacement of a composite material by using auxiliary particles, which comprises the following steps of: embedding (mixing) the auxiliary particles with specific electromagnetic characteristics into the composite material, and accurately measuring the internal displacement of the material by using the response of the particles to external excitation. The auxiliary particles are embedded into the composite material, under the action of an excitation signal, an induction signal of the auxiliary particles is obtained by a receiving coil, and the displacement change of the auxiliary particles in the material can be obtained through inversion through an image reconstruction algorithm. The method is suitable for various occasions where the change of the internal structure of the composite material needs to be monitored, and especially in the environment where real-time and nondestructive monitoring is needed, the method shows unique advantages. Displacement and deformation of particles in the material are monitored in real time, potential mechanical problems of the structure can be found, and therefore potential faults and losses are avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field related to displacement detection, and in particular relates to a method for realizing internal displacement measurement of a composite material by utilizing auxiliary particles. Background Art

[0002] With the rapid development of modern industry and scientific research, the demand for accurate measurement and control of material properties is growing. Especially in the fields of aerospace, automobile manufacturing, civil engineering and biomedical engineering, composite materials are widely used due to their excellent mechanical properties and versatility. However, when composite materials are subjected to external loads, their internal displacement state is often difficult to measure directly, which limits the optimization of material properties and the accuracy of structural design.

[0003] Traditional displacement measurement technologies, such as strain gauges and displacement sensors, have shown certain effectiveness in certain applications, but they have many limitations when facing composite materials. For example, these traditional methods are often difficult to measure the deep structure inside the material, or their performance is unstable under high strain rates or high temperature environments. In addition, they usually require a complex installation process and may interfere with the original properties of the material. In order to overcome these limitations, the present invention proposes a novel displacement measurement method, which utilizes the characteristics of auxiliary particles to achieve accurate measurement of internal displacement of composite materials. Auxiliary particles are special microparticles, which can be millimeter or centimeter-level particles with magnetic or electrical properties. These particles can be embedded in the matrix of the composite material and respond to external stimuli (such as electricity, magnetism, etc.).

[0004] By precisely controlling the external excitation source and monitoring the response of the auxiliary particles, the displacement changes inside the material can be indirectly measured. This method not only provides higher measurement accuracy, but also has the characteristics of non-invasiveness, real-time and strong adaptability. In addition, the introduction of auxiliary particles will not significantly affect the original properties of the material and can be easily integrated into existing measurement systems.

[0005] Therefore, there is an urgent need for a fast, efficient and accurate technology and method for internal displacement detection of composite materials. Summary of the invention

[0006] The method of placing a composite material embedded with auxiliary particles at the center of a magnetic field to detect the object to be tested is to embed auxiliary particles with specific electromagnetic properties in the composite material, such as metal particles, alloys, etc., and utilize the response of these particles to external excitation to achieve accurate measurement of the internal displacement of the material. The magnetic field is composed of a signal generating unit for exciting the auxiliary particles; a signal acquisition unit for receiving the response signal of the auxiliary particles; and a signal processing unit for processing the signal and extracting the displacement information; the auxiliary particles generate a secondary magnetic field due to the eddy current effect under the action of the excitation magnetic field, and generate an induction signal in the induction coil. The response of these particles to external excitation is utilized to achieve accurate measurement of the displacement change inside the composite material according to the response signal and through an image reconstruction algorithm.

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

[0008] A method for measuring the internal displacement of a composite material using auxiliary particles, wherein auxiliary particles with specific electromagnetic properties, such as metal particles, alloys, carbon black, etc., are embedded in the composite material; n (n≥2) uniformly distributed magnetic field detection coils are also arranged around the object to be measured. Under the action of an excitation signal, the displacement change of the auxiliary particles inside the material is obtained by collecting the induction signal and using an image reconstruction algorithm.

[0009] On the basis of the above technical solution, optionally, there is one magnetic field excitation coil and n-1 (n≥2) detection coils, which are evenly arranged around the object to be tested. The detection coil is a coil wound with copper enameled wire.

[0010] On the basis of the above technical solution, optionally, the signal generating unit can generate a signal of a specific excitation frequency.

[0011] On the basis of the above technical solution, preferably, the auxiliary particles are centimeter-scale or millimeter-scale particles with enhanced electromagnetic induction characteristics, and a total of m (m≥1) particles are randomly distributed inside the material.

[0012] On the basis of the above technical solutions, preferably, the particle displacement calculation uses a commonly used image reconstruction algorithm, such as an algebraic algorithm, a filtered back projection method, an iterative algorithm, etc. to determine the center position of the particle.

[0013] Preferably, the measuring device comprises: a signal generating unit for exciting the auxiliary particles, a signal collecting unit for receiving the response signals of the auxiliary particles, and a signal processing unit for processing the signals and extracting the displacement information, wherein the signal generating unit is connected to the PC end, and then connected to the D / A conversion circuit, amplification filtering, and analog switch, the induction coil is connected to the analog switch, the PGA gain amplifier is connected to the A / D collecting circuit, and then connected to the signal processing unit and returned to the PC end.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects:

[0015] The present invention provides a non-destructive, real-time measurement method that can effectively measure the displacement inside a composite material, which is crucial for understanding the deformation behavior of the material during stress.

[0016] By introducing auxiliary particles, real-time monitoring of the internal displacement of composite materials can be achieved, providing real-time data support for fatigue analysis and life prediction of materials.

[0017] Using common image reconstruction algorithms, the center position of the particles can be determined and the displacement of the particles inside the material can be calculated.

[0018] Traditional displacement measurement may require the destruction of materials, while the method of the present invention is non-destructive, which can reduce damage to materials and reduce testing costs. It is applicable to a variety of composite materials, including but not limited to soil, concrete, metal-based, ceramic-based and polymer-based composite materials, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For all other implementations obtained by ordinary technicians in this field without creative work, other drawings can also be obtained based on these drawings. In the drawings:

[0020] Figure 1 The present invention is a flow chart of a method for measuring internal displacement of a composite material using auxiliary particles.

[0021] Figure 2 This is a schematic diagram of the detection hardware structure when n=8.

[0022] Figure 3 The present invention is a structural diagram of a system for measuring internal displacement of a composite material using auxiliary particles, and contains m (m≥1) particles.

[0023] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0024] 1. Excitation coil input end; 2. Induction coil output end; 3. Outer contour of cylindrical composite material; 4. Auxiliary particles with specific electromagnetic properties; 5. Signal generation and signal processing unit; 6. Signal acquisition unit. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail in conjunction with the illustrations. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The present invention will be further described in detail below with reference to the accompanying drawings.

[0027] The method for embedding auxiliary particles inside the composite material in the present invention is: select suitable auxiliary particles 4 with specific electromagnetic properties, such as metal particles, alloys, carbon black, etc., to prepare auxiliary particles. Perform synthesis, surface treatment and other steps, and ensure that the particles can be nearly uniformly distributed in the composite material by mixing, pouring or spraying. The auxiliary particles are doped into the composite matrix material in a certain proportion. A composite material containing m (m≥1) auxiliary particles 4 with specific electromagnetic properties is placed in a magnetic field. Through magnetic field excitation, these auxiliary particles will produce eddy current effects, and then generate induction signals in the detection device. These signals are then received and analyzed by a signal processing unit 6, and the center position of the particles is determined by image reconstruction algorithms such as algebraic methods, filtered back projection methods, iterative algorithms, etc., to calculate the internal displacement of the material.

[0028] The detection hardware structure diagram is as follows: Figure 2 As shown, including:

[0029] —The arrangement of the magnetic field coil sensor when n=8 is shown in the figure. The sensor uses the principle of electromagnetic induction to convert the measured non-electrical quantity (such as displacement, pressure, flow, vibration, etc.) into the change of coil self-inductance or mutual inductance, and then converts it into the change of voltage or current output by the measuring circuit; there are two lead-out terminals: the excitation coil input terminal 1, which is connected to the D / A conversion circuit through the amplification and filtering circuit; the other 7 detection coil output terminals 2;

[0030] — auxiliary particles 4 having specific electromagnetic properties, such as Figure 2 , m (m≥1) randomly distributed auxiliary particles are scattered in the middle, the outer contour of the cylindrical composite material is 3, and the cylindrical shape is placed at the center of the magnetic field. The figure shows the top view effect;

[0031] The displacement measurement system structure diagram is as follows: Figure 3 As shown, including:

[0032] The displacement measurement system can accurately capture and analyze the position change of the auxiliary particles, and includes a signal generation and signal processing unit 5, sensor arrays 1, 2, a signal acquisition unit 6, and the like.

[0033] The present invention realizes real-time monitoring of internal displacement of materials by introducing auxiliary particles, such as Figure 3 As shown, the method includes the following steps S1 to S4.

[0034] S1: m (m≥1) auxiliary particles 4 with specific electromagnetic properties are embedded in the material, and n (n≥2) detection coils are evenly dispersed around the object to be tested.

[0035] The winding of the coil can be said to be single layer or multi-layer

[0036] S2: The signal generating unit 5 generates an excitation signal, which is converted by D / A, amplified and filtered, and then selected by the analog switch before being transmitted to the excitation coil. Based on the principle of electromagnetic induction, the auxiliary particles inside the composite material respond to the magnetic field of the excitation coil and generate an induced voltage signal.

[0037] Considering that the signal is greatly affected by noise during the implementation of step S2, a low-pass filter amplifier is added to ensure the quality and accuracy of the signal.

[0038] S3: Collecting the induction signal. The induction coil surrounding the auxiliary particles will amplify the generated voltage signal through PGA and input it into the signal acquisition unit 6 in real time. The signal acquisition unit 6 collects the output signals of the n-way magnetic induction coils and amplifies and filters the collected signals. The coils are excited in turn and the above steps are repeated.

[0039] The collected signals include both the excitation coil and the induction coil. After the signals are collected, they are uploaded to the host computer through the serial port.

[0040] S4: The signal processing unit 5 receives the voltage signal input by the signal acquisition unit 6, and after signal demodulation, it applies image reconstruction algorithms such as algebraic methods, filtered back projection methods, and iterative algorithms to determine the center position of the particles, and subtracts the data before and after the displacement to calculate the displacement of the particles inside the material.

[0041] Therefore, the present invention utilizes a signal acquisition unit 6 that generates an induced voltage when auxiliary particles respond to an excitation magnetic field, and establishes a method for measuring the internal displacement of a composite material using auxiliary particles. By embedding auxiliary particles inside the material, a coil sensor is used to monitor the slight changes in the position of the particles, thereby accurately capturing the internal displacement of the material during the stress process. Through an image reconstruction algorithm, the monitoring data is converted into an intuitive three-dimensional visualization model to achieve real-time dynamic monitoring of material deformation. This technology is not only easy to operate and fast to measure, but also can significantly improve the measurement accuracy. It is effectively applied to structural health monitoring and performance optimization of materials, and promotes the development of related technologies.

[0042] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0043] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

[0044] The above shows and describes the basic principle, main features and advantages of the present invention. The protection scope required by the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for measuring internal displacement of a composite material using auxiliary particles, characterized in that: include: Prepare the composite material to be tested, embed m auxiliary particles with electromagnetic properties in the composite material, prepare a measuring device, which includes n induction coils, use an external excitation source to generate an excitation magnetic field, the excitation magnetic field excites the auxiliary particles to generate response signals, the n induction coils receive the response signals generated by the auxiliary particles, upload the response signals to the host computer, circulate the excitation coils, and the signal processing device continuously collects the response signals received by the induction coils, and determines the center position of the auxiliary particles before and after displacement through an image reconstruction algorithm, thereby analyzing the displacement changes inside the composite material. This method is applied to internal displacement detection of composite materials.

2. The method for measuring internal displacement of a composite material using auxiliary particles according to claim 1, characterized in that: The detection method is an active detection form, which requires external stimulation, such as a signal generator, and then diagnoses the health status of the material structure by analyzing the sensing signal received by the sensor.

3. The method for measuring internal displacement of a composite material using auxiliary particles according to claim 1, characterized in that: The auxiliary particles are centimeter-scale or millimeter-scale particles with electrical or magnetic properties, wherein m particles are randomly distributed inside the material, and the auxiliary particles include a combination of one or more of metal particles, alloys, and carbon black.

4. The method for measuring internal displacement of a composite material using auxiliary particles according to claim 1, characterized in that: The external excitation source can generate excitation signals with different frequencies.

5. The method for measuring internal displacement of a composite material using auxiliary particles according to claim 1, characterized in that: The induction coils are evenly arranged around the object to be tested, with 1 excitation sensor and n-1 detection sensors.

6. The method for measuring internal displacement of a composite material using auxiliary particles according to claim 1, characterized in that: The induction coil is a coil wound with copper enameled wire.

7. The method for measuring internal displacement of a composite material using auxiliary particles according to claim 1, characterized in that: The coils are excited in turn in a cycle to obtain induced voltage signals of all coils respectively.

8. The method for measuring internal displacement of a composite material using auxiliary particles according to claim 1, characterized in that: The measuring device includes: a signal generating unit for exciting auxiliary particles, a signal collecting unit for receiving auxiliary particle response signals, and a signal processing unit for processing signals and extracting displacement information, wherein the signal generating unit is connected to a PC end, and then connected to a D / A conversion circuit, an amplifying filter, and an analog switch, the induction coil is connected to the analog switch, the PGA gain amplifier is connected to the A / D collecting circuit, and then connected to the signal processing unit and returned to the PC end.

9. The method for measuring internal displacement of a composite material using auxiliary particles according to claim 1, characterized in that: The center position of the particle can be determined through commonly used image reconstruction algorithms, such as algebraic methods, filtered back projection methods, and iterative algorithms.

10. The method for measuring internal displacement of composite materials using auxiliary particles according to claim 1, characterized in that: Detection is performed in an empty field, i.e., without the test object, and in a field, but before the test object is placed, to determine the initial position of the particles. After the displacement occurs, the difference between the subsequent monitoring data at different times and the initial position of the particles is used as the displacement of the particles inside the material over time.

Images