Carbon fiber laminated plate and preparation method thereof, and carbon fiber laminated plate assembly capable of adjusting damping performance
By coating piezoelectric materials and conductive layers into carbon fiber laminates and combining them with variable resistors, the problem of low damping performance of carbon fiber composite materials was solved, achieving high damping and adjustable damping, thereby improving the vibration suppression capability and self-sensing function of the structure.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-25
- Publication Date
- 2026-04-03
AI Technical Summary
Carbon fiber composites have low damping performance, making it difficult to effectively suppress structural vibrations, which affects service life and system stability. Existing methods to improve damping suffer from problems such as increased structural weight, non-adjustable damping, and poor performance stability.
By coating piezoelectric materials into carbon fiber laminates and forming a conductive layer, combined with variable resistance, the damping performance can be adjusted to adapt to different working conditions. The preparation method includes mixing piezoelectric particles with organic binders, coating, polarization treatment and hot pressing to form a piezoelectric coating of appropriate thickness to improve the damping performance of composite materials.
The high damping and adjustable damping of carbon fiber laminates were achieved, enabling them to adaptively respond to various working conditions. This significantly improved the vibration suppression capability and vibration self-sensing function of the structure, reduced design costs, and improved the stability of damping performance.
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Figure CN121777516A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of this application relate to the field of products containing thin layers with different physical properties, and particularly to a carbon fiber laminate and its preparation method, and a carbon fiber laminate assembly capable of adjusting damping performance. Background Technology
[0002] The statements herein are provided merely as background information in connection with this application and do not necessarily constitute prior art.
[0003] Carbon fiber composites possess high specific strength, high specific modulus, and good corrosion resistance, making them commonly used in aerospace, rail transportation, wind power, and high-end manufacturing. However, carbon fiber composites exhibit relatively low bulk damping performance, making it difficult to effectively suppress structural vibrations and impacting service life and system stability. Therefore, it is necessary to improve the damping performance of carbon fiber composites to effectively suppress harmful vibrations, improve fatigue life, and enhance operational accuracy.
[0004] Traditional methods for improving damping often rely on sandwich structure design or polymer modification, but these methods often suffer from problems such as increased structural weight, non-adjustable damping, and poor damping performance stability. Summary of the Invention
[0005] A brief overview of this application is provided below to offer a basic understanding of certain aspects thereof. It should be understood that this overview is not an exhaustive summary of the application. It is not intended to identify key or essential parts of the application, nor is it intended to limit its scope. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.
[0006] This application provides a carbon fiber laminate, comprising: multiple carbon fiber layers, multiple carbon fiber layers coated with piezoelectric materials, silver paste coated on the multiple carbon fiber layers coated with piezoelectric materials to form a conductive layer, resin coated on the multiple carbon fiber layers and the multiple carbon fiber layers coated with piezoelectric materials, and the multiple carbon fiber layers coated with piezoelectric materials are spaced apart between the carbon fiber layers.
[0007] The carbon fiber laminate provided in the embodiments of this application improves the structural damping performance of the composite material by coating the carbon fiber layer with piezoelectric material and spacing the coated carbon fiber layer with the uncoated carbon fiber layer.
[0008] Another aspect of this application provides a carbon fiber laminate assembly capable of adjusting damping performance, which includes the aforementioned carbon fiber laminate and a variable resistor, with a conductive layer electrically connected to the variable resistor.
[0009] The carbon fiber laminate assembly with adjustable damping performance provided in the embodiments of this application can adjust the damping performance of the carbon fiber laminate by changing the resistance value of the variable resistor, so that the carbon fiber laminate assembly can adaptively respond to various working conditions.
[0010] This application also provides a method for preparing the aforementioned carbon fiber laminate, comprising the following steps: S10: removing the sizing agent from the carbon fiber woven fabric; S20: mixing piezoelectric particles with an organic binder; S30: coating the mixture obtained in step S20 onto the surface of the carbon fiber woven fabric obtained in step S10, reaching a predetermined thickness; S40: heating the carbon fiber woven fabric obtained in step S30 to make the mixture adhere to the surface of the carbon fiber woven fabric, and determining the thickness of the mixture, repeating steps S30-S40 until the thickness reaches the predetermined thickness; S50: polarizing the carbon fiber woven fabric obtained in step S40; S60: coating the surface of the carbon fiber woven fabric obtained in step S50 with silver paste and setting lead wires; S70: coating the surface of the carbon fiber woven fabric obtained in step S60 with resin; S80: coating the surface of ordinary carbon fiber woven fabric with resin; S90: setting the ordinary carbon fiber woven fabric obtained in step S80 and the carbon fiber woven fabric obtained in step S70 alternately and hot-pressing them into shape.
[0011] The method for preparing the aforementioned carbon fiber laminate provided in the embodiments of this application reliably constructs a mixture of piezoelectric particles and organic binder on the surface of carbon fibers to form a piezoelectric coating of suitable thickness, thereby giving the composite material structure high damping, adjustable damping, and vibration self-sensing function. Attached Figure Description
[0012] To further illustrate the above and other advantages and features of this application, the specific embodiments of this application will be described in more detail below with reference to the accompanying drawings. The drawings, together with the following detailed description, are included in and form a part of this specification. Elements having the same function and structure are indicated by the same reference numerals. It should be understood that these drawings only depict typical examples of this application and should not be considered as limiting the scope of this application.
[0013] Figure 1 This is a schematic diagram comparing the vibration attenuation curves of a carbon fiber laminate coated with a first thickness coating and an uncoated carbon fiber laminate obtained by the preparation method provided in the embodiments of this application. Figure 2 This is a schematic diagram comparing the vibration attenuation curves of a carbon fiber laminate coated with a second thickness coating and an uncoated carbon fiber laminate obtained by the preparation method provided in the embodiments of this application. Figure 3This is a schematic diagram comparing the vibration attenuation curves of a carbon fiber laminate coated with a third thickness coating and an uncoated carbon fiber laminate obtained by the preparation method provided in the embodiments of this application. Figure 4 This is a schematic diagram illustrating the damping adjustability of a carbon fiber laminate coated with a first thickness coating, obtained by the preparation method provided in the embodiments of this application. Figure 5 This is a schematic diagram illustrating the damping adjustability of a carbon fiber laminate coated with a second thickness coating obtained by the preparation method provided in the embodiments of this application. Figure 6 This is a schematic diagram illustrating the damping adjustability of a carbon fiber laminate coated with a third thickness coating obtained by the preparation method provided in the embodiments of this application. Figure 7 This is a schematic diagram showing the voltage values output by a carbon fiber laminate coated with a third thickness coating obtained by the preparation method provided in the embodiments of this application under different amplitudes. Figure 8 This is a schematic diagram showing the frequency response characteristics of the output voltage of a carbon fiber laminate coated with a third thickness coating obtained by the preparation method provided in the embodiments of this application under different amplitudes. Detailed Implementation
[0014] Exemplary embodiments of this application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the development of any such actual embodiment to achieve the developer's specific goals, such as complying with constraints related to the system and business, and these constraints may vary depending on the implementation. Furthermore, it should be understood that while development work can be very complex and time-consuming, such development work is merely a routine task for those skilled in the art who benefit from the content of this application.
[0015] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the equipment structure and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.
[0016] The following disclosure provides several different implementations or examples for carrying out this application. To simplify the disclosure of this application, specific examples of components and methods are described below. Of course, these are merely examples and are not intended to limit this application. In the description of the embodiments of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0017] Piezoelectric materials possess the ability to convert mechanical energy into electrical energy, and their energy dissipation behavior can be influenced by adjusting electrical boundary conditions. Furthermore, they can actively apply force / displacement through the inverse piezoelectric effect. However, integrating piezoelectric materials into lightweight carbon fiber reinforced composite structures presents challenges such as material compatibility, interface stability, and insufficient functional integration. For instance, while maintaining the lightweight and high-strength properties of the composite material, it is still impossible to reliably construct a functional piezoelectric layer on the fiber surface, thereby achieving active control of damping performance and real-time sensing of the structural state.
[0018] To address the aforementioned issues, one embodiment of this application provides a carbon fiber laminate comprising: multiple carbon fiber layers, multiple carbon fiber layers coated with piezoelectric materials, silver paste coated on the multiple carbon fiber layers coated with piezoelectric materials to form a conductive layer, resin coated on the multiple carbon fiber layers and the multiple carbon fiber layers coated with piezoelectric materials, the multiple carbon fiber layers coated with piezoelectric materials being spaced apart between the carbon fiber layers.
[0019] The carbon fiber laminate provided in the embodiments of this application improves the structural damping performance of the composite material by coating the carbon fiber layer with piezoelectric material and spacing the coated carbon fiber layer with the uncoated carbon fiber layer.
[0020] Another embodiment of this application provides a carbon fiber laminate assembly capable of adjusting damping performance, which includes the aforementioned carbon fiber laminate and a variable resistor, with a conductive layer electrically connected to the variable resistor.
[0021] The carbon fiber laminate assembly with adjustable damping performance provided in the embodiments of this application can adjust the damping performance of the carbon fiber laminate by changing the resistance value of the variable resistor, so that the carbon fiber laminate assembly can adaptively respond to various working conditions.
[0022] Another aspect of this application provides a method for preparing the aforementioned carbon fiber laminate, comprising the following steps: S10: removing the sizing agent from the carbon fiber woven fabric; S20: mixing piezoelectric particles with an organic adhesive; S30: coating the mixture obtained in step S20 onto the surface of the carbon fiber woven fabric obtained in step S10, reaching a predetermined thickness; S40: heating the carbon fiber woven fabric obtained in step S30 to cause the mixture to adhere to the surface of the carbon fiber woven fabric, and determining the thickness of the mixture, repeating steps S30-S40 until the thickness reaches the predetermined thickness; S50: polarizing the carbon fiber woven fabric obtained in step S40; S60: coating the surface of the carbon fiber woven fabric obtained in step S50 with silver paste and setting lead wires; S70: coating the surface of the carbon fiber woven fabric obtained in step S60 with resin; S80: coating the surface of ordinary carbon fiber woven fabric with resin; S90: alternating the ordinary carbon fiber woven fabric obtained in step S80 and the carbon fiber woven fabric obtained in step S70 and hot-pressing them into shape.
[0023] The method for preparing the aforementioned carbon fiber laminate provided in the embodiments of this application reliably constructs a mixture of piezoelectric particles and organic binder on the surface of carbon fibers to form a piezoelectric coating of suitable thickness, thereby giving the composite material structure high damping, adjustable damping, and vibration self-sensing function.
[0024] In some embodiments, in step S40, the heating temperature can be set to 1000-1200°C, and the mixture can be kept at this temperature in air for a predetermined time (e.g., 5-20 min) to allow the organic binder to completely pyrolyze and transform in situ. This forms a nanoscale carbon-ceramic composite interface transition layer (e.g., 2-15 nm thick) between the piezoelectric particles and between the piezoelectric particles and the carbon fiber, improving the interfacial bonding between the piezoelectric phase and the carbon fiber matrix. This also generates a dual energy dissipation mechanism of triboelectricity and conductivity during vibration, enhancing damping performance. The formed nanoscale carbon-ceramic composite interface transition layer, while ensuring the mechanical stability of the interface, also retains the conductive properties of the carbon phase, which is beneficial for the piezoelectric layer to achieve stable electromechanical energy conversion under external variable resistance conditions.
[0025] In some embodiments, in step S30, a coating layer of predetermined thickness can be obtained by multiple coating processes, thereby achieving precise control of the thickness of the piezoelectric coating layer and ensuring that the actual prepared thickness of the coating layer has a controllable error compared with the theoretically designed thickness.
[0026] In some embodiments, in step S30, coating can also be performed by radio frequency plasma spraying or atmospheric plasma spraying, with a spraying power of 15-35kW, a powder feeding rate of 20-50g / min, and a spraying temperature controlled at 300-600°C. The coating is performed while the fiber is under tension of 0.5-3N, so that the molten piezoelectric particles are attached to the carbon fiber with a flattening rate of ≥60%, and cooled to room temperature while maintaining tension.
[0027] In some embodiments, step S30 further includes the following steps: S31: determining a predetermined thickness value; S32: preliminarily determining the mass of the mixture based on the predetermined thickness value determined in step S31; S33: uniformly coating the mixture onto the carbon fiber surface using a scraping method based on the mass of the mixture; S34: processing the carbon fiber woven fabric obtained in step S33 using the method described in step S40; S35: observing the thickness of the coating layer on the carbon fiber woven fabric after processing in step S34 using a scanning electron microscope; S36: establishing a relationship between the mass of step S32 and the thickness of step S35 based on the thickness of the coating layer obtained in step S35; S37: determining the accurate mass of the mixture based on the relationship determined in step S36; S38: repeating steps S32 to S35 based on the accurate mass of the mixture determined in step S37 until the predetermined thickness value is achieved. By applying the coating multiple times, a more uniform and precise piezoelectric coating layer can be obtained.
[0028] Figure 1 This is a schematic diagram comparing the vibration attenuation curves of a carbon fiber laminate coated with a first thickness coating and an uncoated carbon fiber laminate obtained by the preparation method provided in the embodiments of this application. In some embodiments, such as Figure 1 As shown, two carbon fiber laminates are given initial perturbation, and both vibrate freely. Figure 1 The purple line represents the vibration decay curve of the uncoated carbon fiber laminate, and the blue line represents the vibration decay curve of the carbon fiber laminate (BTO1) coated with a first thickness of coating, which can be set to 50 μm.
[0029] Figure 2 This is a schematic diagram comparing the vibration attenuation curves of a carbon fiber laminate coated with a second thickness coating and an uncoated carbon fiber laminate obtained by the preparation method provided in the embodiments of this application. In some embodiments, such as Figure 2 As shown, two carbon fiber laminates are given initial perturbation, and both vibrate freely. Figure 2 The purple line represents the vibration decay curve of the uncoated carbon fiber laminate, and the red line represents the vibration decay curve of the carbon fiber laminate (BTO2) coated with a second thickness of coating, which can be set to 100 μm.
[0030] Figure 3This is a schematic diagram comparing the vibration attenuation curves of a carbon fiber laminate coated with a third thickness coating and an uncoated carbon fiber laminate obtained by the preparation method provided in the embodiments of this application. In some embodiments, such as Figure 3 As shown, two carbon fiber laminates are given initial perturbation, and both vibrate freely. Figure 3 The purple line represents the vibration decay curve of the uncoated carbon fiber laminate, and the pink line represents the vibration decay curve of the carbon fiber laminate (BTO3) coated with a third thickness of coating, which can be set to 150 μm.
[0031] like Figures 1-3 As shown, the extension length and range of the purple region are much greater than those of the blue, red, and pink regions, indicating that the vibration duration of the uncoated carbon fiber laminate is longer. This demonstrates that the damping performance of the three coated carbon fiber laminates obtained by the preparation method provided in the embodiments of this application is superior to that of the uncoated carbon fiber laminate. Figure 2 The BTO2 damping curve in the middle drops the fastest, which can shorten the vibration damping time by 83% and make it calm in the shortest time, thus exhibiting the best damping performance.
[0032] In some embodiments, step S31 further includes the following steps: S311: determining the effective capacitance factor of the coating layer of the prepared carbon fiber laminate; S312: determining the electromechanical-interface coupling efficiency factor of the coating layer of the prepared carbon fiber laminate; S313: determining the electrical matching frequency factor of the prepared carbon fiber laminate; S314: determining the target additional damping requirement of the prepared carbon fiber laminate; S315: determining the value of a predetermined thickness based on the effective capacitance factor, the electromechanical-interface coupling efficiency factor, the electrical matching frequency factor, and the target additional damping requirement.
[0033] Compared to using empirical trial and error or a single capacitance formula to determine the thickness, the above-mentioned step-by-step method for determining the predetermined thickness achieves quantitative optimization of the piezoelectric layer thickness, which can stably improve the damping ratio of carbon fiber laminates, shorten the development cycle, and avoid material waste from reverse sampling tests. At the same time, this method couples the energy consumption of residual carbon at the interface with electrical matching and takes into account the contribution of interface damping.
[0034] In some embodiments, the values of effective capacitance factor, electromechanical-interface coupling efficiency factor, electrical matching frequency factor, target additional damping requirement, and predetermined thickness conform to the following relationship: ;in For the predetermined thickness value, The effective capacitance factor, For electrical matching frequency factor, Add damping requirements to the target. This is the electromechanical-interface coupling efficiency factor.
[0035] Compared to existing simple capacitance formulas or numerical simulations, the above relationship is used to determine the thickness, introducing block coupling and considering the exponential correction of the capacitance factor by the residual carbon rate. This avoids the prediction bias caused by neglecting interface energy dissipation in existing methods, has strong engineering applicability, significantly reduces design costs, and improves the stability of damping performance.
[0036] In some embodiments, step S311 further includes the following steps: S3111: determining the area of the coating layer of the carbon fiber laminate; S3112: determining the dielectric constant of the coating layer of the carbon fiber laminate; S3113: determining the residual carbon ratio of the coating layer of the carbon fiber laminate; S3114: determining the value of the effective capacitance factor based on the area of the coating layer, the dielectric constant of the coating layer, and the residual carbon ratio of the coating layer. Compared to calculation using only the simple dielectric constant, the above method optimizes the capacitance of the piezoelectric layer under the microscopic conductive network by indexing the residual carbon ratio, making the calculation of the conversion of mechanical energy to electrical energy more accurate. Existing methods do not achieve residual carbon indexing correction and cannot achieve equivalent interface-electrical synergy.
[0037] In some embodiments, the values of the coating area, the dielectric constant of the coating, the carbon residue of the coating, and the effective capacitance factor conform to the following relationship: ;in, The effective capacitance factor, The area of the coating layer, The dielectric constant of the coating layer is . The residual carbon ratio of the coating layer is used. Compared with existing methods that only use simple dielectric constants for calculation, the above method determines the effective capacitance factor, introduces the cube root correction of the residual carbon ratio, quantifies the enhancing effect of residual carbon on capacitance effectiveness, and makes the overall damping ratio calculation more accurate. Existing methods cannot achieve the exponential correction of residual carbon, and therefore cannot achieve equal interface-electrical synergy.
[0038] In some embodiments, step S312 further includes the following steps: S3121: determining the generalized electromechanical coupling coefficient of the coating layer of the prepared carbon fiber laminate; S3122: determining the interface correction coefficient of the coating layer of the prepared carbon fiber laminate; S3123: determining the value of the electromechanical-interface coupling efficiency factor of the coating layer based on the generalized electromechanical coupling coefficient and the interface correction coefficient of the coating layer. Compared with existing methods that only use the generalized electromechanical coupling coefficient, the above method for determining the electromechanical-interface coupling efficiency factor introduces an interface correction coefficient, quantifies the enhancing effect of residual carbon slip on coupling efficiency, effectively improves the peak matching accuracy of electrical damping, and enhances the accuracy of damping ratio calculation. Existing methods lack this interface correction and cannot achieve accurate calculation.
[0039] In some embodiments, the generalized electromechanical coupling coefficient of the coating, the interface correction coefficient of the coating, and the electromechanical-interface coupling efficiency factor of the coating conform to the following relationship: ;in, The electromechanical-interface coupling efficiency factor of the coating layer. The generalized electromechanical coupling coefficient of the coating layer. This is the interface correction factor for the coating layer. Factors such as interfacial shear strength and residual carbon thickness are factored in using this interface correction factor. It is stated that the enhancement effect of residual carbon slip on coupling efficiency is taken into account, which effectively improves the peak matching accuracy of electrical damping and enhances the accuracy of damping ratio calculation.
[0040] In some embodiments, step S313 further includes the following steps: S3131: determining the natural frequency of the prepared carbon fiber laminate; S3132: determining the external resistance value of the prepared carbon fiber laminate; S3133: determining the electrical matching frequency factor of the carbon fiber laminate based on its natural frequency and external resistance value. Compared with existing methods that use fixed resistance matching, the above method for determining the electrical matching frequency factor dynamically considers the interaction between modal frequencies and external resistance, making peak matching more accurate and expanding the damping control range. This effectively shortens the vibration decay time, thereby improving multi-condition adaptability. Existing methods cannot achieve this frequency-resistance coupling optimization.
[0041] In some embodiments, the natural frequency of the carbon fiber laminate, the external resistance of the carbon fiber laminate, and the electrical matching frequency factor of the carbon fiber laminate conform to the following relationship: ;in, The electrical matching frequency factor for carbon fiber laminates. The natural frequency of the carbon fiber laminate is . This represents the external resistance value of the carbon fiber laminate. Compared to existing methods, the above approach considers the dynamic adjustment between frequency and resistance matching, realizing the conversion of mechanical energy into electrical energy, and incorporating the external resistance into the structural damping.
[0042] In some embodiments, step S314 further includes the following steps: S3141: determining the target first-order damping ratio of the prepared carbon fiber laminate; S3142: determining the damping of the carbon fibers in the prepared carbon fiber laminate; S3143: determining the damping of the interface layer of the prepared carbon fiber laminate; S3144: determining the target additional damping requirement based on the target first-order damping ratio, the damping of the carbon fibers, and the damping of the interface layer. This method of determining the target additional damping requirement considers interface damping, accurately calculates the additional requirement after subtracting the baseline, improves prediction accuracy, and avoids performance deficiencies caused by underestimating interface energy dissipation in existing methods.
[0043] In some embodiments, the target first-order damping ratio, the damping of the carbon fiber, the damping of the interface layer, and the target additional damping requirement conform to the following relationship: ;in Add damping requirements to the target. The target first-order damping ratio for the carbon fiber laminate. For the damping of carbon fibers in fiber laminates, This represents the damping of the interface layer in the carbon fiber laminate. By subtracting the interface damping, the overall calculation accuracy is effectively improved.
[0044] In some embodiments, the damping of the interface layer of the carbon fiber laminate It can be determined in the following way: ,in, The shear yield strength of the transition layer. The interface electro-mechanical coupling coefficient, For the thickness of the transition layer, For modal interface stress, The residual carbon conductivity, For the resistivity of the piezoelectric layer, The critical slip distance, Let be the order of the Fourier odd harmonic, taking a positive odd number. Wherein, Defined as a leakage current auxiliary energy consumption correction term.
[0045] In some embodiments, in step S20, the piezoelectric particles may be lead zirconate titanate, barium titanate, zinc oxide, or a mixture thereof, and the organic binder may be one or more of gum arabic, polyvinyl alcohol, gelatin, or sodium carboxymethyl cellulose.
[0046] In some embodiments, in step S20, the organic binder may be set to have a residual carbon content of 2.8-5.2 wt% after pyrolysis.
[0047] In some embodiments, in step S50, polarization can be performed for 15-45 minutes at 25-100°C and an electric field strength of 2-4 kV / mm, and the residual polarization intensity Pr is measured to be ≥12 μC / cm² within 24 hours after polarization.
[0048] In some embodiments, in step S60, the lead wire material can be set as a copper sheet or copper mesh with a thickness of <0.1mm.
[0049] In some embodiments, in step S10, the carbon fiber woven fabric can be refluxing with acetone to remove the sizing agent, thereby ensuring the adhesion and stability of the piezoelectric coating.
[0050] In some embodiments, in step S90, a vacuum bag pressing or autoclave process can be used to cure and shape the material at a temperature 20°C below the Curie temperature of the piezoelectric material and a pressure of 0.8-1.8 MPa.
[0051] In some embodiments, after the ordinary carbon fiber woven fabric obtained in step S80 and the carbon fiber woven fabric obtained in step S70 are hot-pressed together, they can be connected in parallel or in series to an external programmable resistor network (0-10) via the lead wires set in step S60. 9 The damping ratio is continuously adjustable within the range of 0.8%-12.4% (Ω adjustable), which facilitates real-time monitoring of the mechanical behavior of the material structure, such as amplitude, using a piezoelectric signal acquisition system, and allows for timely diagnosis and feedback of potential problems. Table 1 shows the damping ratio data of piezoelectric coatings of different thicknesses under different external resistance conditions. As shown in Table 1, even in the open-circuit state, the damping ratios of BTO1, BTO2, and BTO3 are much higher than the 0.695 of the uncoated one, proving that the coating material itself can enhance damping. Moreover, in all circuit states, BTO2 has the highest damping ratio, indicating that its damping performance is optimal.
[0052] Table 1 Damping ratio of piezoelectric coatings of different thicknesses under different external resistance conditions
[0053] Figure 4 This is a schematic diagram illustrating the damping adjustability of a carbon fiber laminate coated with a first thickness coating, obtained by the preparation method provided in the embodiments of this application. In some embodiments, such as... Figure 4 As shown, the blue curve represents an external resistor of 10. 9 The pink curve represents the change of the response amplitude of BTO1 over time when the external resistance is 0. It can be seen that the decay rate of the blue curve is slower than that of the pink curve. That is, under the same conditions, the low external resistance has a higher vibration suppression capability than the high external resistance.
[0054] Figure 5 This is a schematic diagram illustrating the damping adjustability of a carbon fiber laminate coated with a second thickness coating obtained by the preparation method provided in the embodiments of this application. In some embodiments, such as... Figure 5 As shown, the blue curve represents an external resistor of 10. 9 The pink curve represents the change of the response amplitude of BTO2 with time when the external resistance is 0. It can be seen that the vibration decay rate of the blue curve is slower than that of the pink curve. That is, under the same conditions, the external low resistance has a higher vibration suppression capability than the external high resistance.
[0055] Figure 6This is a schematic diagram illustrating the damping adjustability of a carbon fiber laminate coated with a third thickness coating obtained by the preparation method provided in the embodiments of this application. In some embodiments, such as... Figure 6 As shown, the blue curve represents an external resistor of 10. 9 The pink curve represents the change in the response amplitude of BTO3 over time when the external resistance is 0 Ω. It can be seen that the vibration decay rate of the blue curve is slower than that of the pink curve, meaning that under the same conditions, a lower external resistance provides higher vibration suppression than a higher external resistance. BTO1, BTO2, and BTO3 suppress more vibration energy in the low-resistance state than in the high-resistance state, indicating that BTO2 and BTO3 possess more complex and superior damping performance and stronger internal energy dissipation capabilities. Furthermore, by adjusting the external resistance value, they can be adapted to different operating conditions.
[0056] Figure 7 This is a schematic diagram showing the voltage values output by a carbon fiber laminate coated with a third thickness coating at different amplitudes, obtained by the preparation method provided in the embodiments of this application. In some embodiments, such as... Figure 7 As shown, the orange curve represents an amplitude of 10 mm, the green curve represents an amplitude of 20 mm, the blue curve represents an amplitude of 30 mm, the pink curve represents an amplitude of 40 mm, and the purple curve represents an amplitude of 50 mm. As time goes on, the larger the amplitude of BTO3, the larger the output voltage value, indicating that the BTO3 coating effectively converts mechanical energy into electrical energy. The voltage output can accurately reflect the vibration intensity, indicating that BTO3 has good sensing properties and can achieve self-sensing to adapt to various working conditions.
[0057] Figure 8 This is a schematic diagram illustrating the frequency response characteristics of the output voltage of a carbon fiber laminate coated with a third thickness coating obtained by the preparation method provided in the embodiments of this application under different amplitudes. In some embodiments, such as Figure 8 As shown, this reflects the frequency response of BTO3 at different amplitudes under different vibration intensities. (The text abruptly ends here.) Figure 8 The natural frequencies of the structure are clearly reflected: the first natural frequency is approximately 18 Hz, the second natural frequency is approximately 36 Hz, and the third natural frequency is approximately 54 Hz. Furthermore, as the vibration intensity increases, the characteristics of the structural frequency response also change, with the proportion of the first natural frequency gradually decreasing while the proportion of the second natural frequency continuously increases. This indicates that the vibration mode of the structure changes with the increase of vibration intensity, suggesting that this coating can also be used for monitoring the vibration state of structures.
[0058] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.
[0059] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.
Claims
1. A carbon fiber laminate, characterized in that, It includes: Multi-layer carbon fiber, multi-layer piezoelectric material coated carbon fiber, A silver paste is coated onto the carbon fiber layer coated with the multilayer piezoelectric material to form a conductive layer. Resin is coated onto the multilayer carbon fiber layers and the multilayer piezoelectric material-coated carbon fiber layers. The carbon fiber layers coated with the multilayer piezoelectric material are spaced apart between the carbon fiber layers.
2. A carbon fiber laminate assembly with adjustable damping performance, characterized in that, It includes the carbon fiber laminate as described in claim 1 and a variable resistor. The conductive layer is electrically connected to the variable resistor.
3. A method for preparing the carbon fiber laminate of claim 1, characterized in that, It includes the following steps: S10: Removes the sizing agent from the carbon fiber woven fabric; S20: Mix piezoelectric particles with an organic binder; S30: Coat the mixture obtained in step S20 onto the surface of the carbon fiber woven fabric obtained in step S10, and achieve a predetermined thickness; S40: Heat the carbon fiber woven fabric obtained in step S30 to make the mixture adhere to the surface of the carbon fiber woven fabric, and determine the thickness of the mixture. Repeat steps S30-S40 until the thickness reaches the predetermined thickness. S50: Polarize the carbon fiber woven fabric obtained in step S40; S60: Coat the surface of the carbon fiber woven fabric obtained in step S50 with silver paste and set lead wires; S70: Coat the surface of the carbon fiber woven fabric obtained in step S60 with resin; S80: Resin is coated on the surface of ordinary carbon fiber woven fabric; S90: The ordinary carbon fiber woven fabric obtained in step S80 and the carbon fiber woven fabric obtained in step S70 are spaced apart and hot-pressed together.
4. The method according to claim 3, characterized in that, In step S40, the heating temperature is set to 1000-1200℃ and the temperature is maintained in an air atmosphere for a predetermined time to allow the organic adhesive to be completely pyrolyzed and transformed in situ, forming a nanoscale carbon-ceramic composite interface transition layer between piezoelectric particles and between piezoelectric particles and carbon fibers.
5. The method according to claim 3, characterized in that, In step S30, a coating layer of predetermined thickness is obtained by applying the coating multiple times.
6. The method according to claim 5, characterized in that, Step S30 also includes the following steps: S31: Determine the value of the predetermined thickness; S32: Based on the predetermined thickness value determined in step S31, preliminarily determine the mass of the mixture; S33: Based on the mass of the mixture, the mixture is uniformly coated onto the surface of the carbon fiber using a scraping method; S34: Process the carbon fiber woven fabric obtained in step S33 using the method in step S40; S35: Observe the thickness of the carbon fiber woven fabric coating after step S34 using a scanning electron microscope. S36: Obtain the thickness of the coating layer according to step S35, and establish the relationship between the quality described in step S32 and the thickness described in step S35; S37: Determine the accurate mass of the mixture based on the relationship established in step S36; S38: Based on the accurate mass of the mixture determined in step S37, repeat steps S32 to S35 until the predetermined thickness value is achieved.
7. The method according to claim 6, characterized in that, Step S31 also includes the following steps: S311: Determine the effective capacitance factor of the coating layer of the prepared carbon fiber laminate; S312: Determine the electromechanical-interface coupling efficiency factor of the coating layer of the prepared carbon fiber laminate; S313: Determine the electrical matching frequency factor of the prepared carbon fiber laminate; S314: Determine the target additional damping requirements for the prepared carbon fiber laminate; S315: Determine the value of the predetermined thickness based on the effective capacitance factor, the electromechanical-interface coupling efficiency factor, the electrical matching frequency factor, and the target additional damping requirement.
8. The method according to claim 7, characterized in that, The values of the effective capacitance factor, the electromechanical-interface coupling efficiency factor, the electrical matching frequency factor, the target additional damping requirement, and the predetermined thickness conform to the following relationship: ； in The value of the predetermined thickness. This refers to the effective capacitance factor. The electrical matching frequency factor, Add damping requirements to the target. The electromechanical-interface coupling efficiency factor is denoted as .
9. The method according to claim 7, characterized in that, Step S311 also includes the following steps: S3111: Determine the area of the coating layer of the carbon fiber laminate; S3112: Determine the dielectric constant of the coating layer of the carbon fiber laminate; S3113: Determine the residual carbon content of the coating layer of the carbon fiber laminate; S3114: Determine the value of the effective capacitance factor based on the area of the coating layer, the dielectric constant of the coating layer, and the residual carbon content of the coating layer.
10. The method according to claim 9, characterized in that, The area of the coating layer, the dielectric constant of the coating layer, the carbon residue of the coating layer, and the value of the effective capacitance factor conform to the following relationship: ； in, This refers to the effective capacitance factor. The area of the coating layer, The dielectric constant of the coating layer is . The residual carbon content of the coating layer is denoted as .
11. The method according to claim 7, characterized in that, Step S312 also includes the following steps: S3121: Determine the generalized electromechanical coupling coefficient of the coating layer of the prepared carbon fiber laminate; S3122: Determine the interface correction coefficient of the coating layer of the prepared carbon fiber laminate; S3123: Determine the value of the electromechanical-interface coupling efficiency factor of the coating layer based on the generalized electromechanical coupling coefficient and the interface correction coefficient of the coating layer.
12. The method according to claim 11, characterized in that, The generalized electromechanical coupling coefficient, the interface correction coefficient, and the electromechanical-interface coupling efficiency factor of the coating layer conform to the following relationship: ； in, The electromechanical-interface coupling efficiency factor of the coating layer is given. The generalized electromechanical coupling coefficient of the coating layer is... is the interface correction coefficient of the coating layer.
13. The method according to claim 7, characterized in that, Step S313 also includes the following steps: S3131: Determine the natural frequency of the prepared carbon fiber laminate; S3132: Determine the external resistance value of the prepared carbon fiber laminate; S3133: Determine the electrical matching frequency factor of the carbon fiber laminate based on its natural frequency and the external resistance value of the carbon fiber laminate.
14. The method according to claim 11, characterized in that, The natural frequency of the carbon fiber laminate, the external resistance of the carbon fiber laminate, and the electrical matching frequency factor of the carbon fiber laminate conform to the following relationship: ； in, The electrical matching frequency factor of the carbon fiber laminate is [missing information]. The natural frequency of the carbon fiber laminate is given. The external resistance value of the carbon fiber laminate is given.
15. The method according to claim 7, characterized in that, Step S314 also includes the following steps: S3141: Determine the target first-order damping ratio of the prepared carbon fiber laminate; S3142: Determine the damping of the carbon fibers in the prepared carbon fiber laminate; S3143: Determine the damping of the interface layer of the prepared carbon fiber laminate; S3144: Determine the target additional damping requirement based on the target first-order damping ratio, the damping of the carbon fiber, and the damping of the interface layer.
16. The method according to claim 15, characterized in that, The target first-order damping ratio, the damping of the carbon fiber, the damping of the interface layer, and the target additional damping requirement conform to the following relationship: ； in Add damping requirements to the target. The target first-order damping ratio of the carbon fiber laminate is given. The damping of the carbon fibers in the fiber laminate. The damping of the interface layer of the carbon fiber laminate.