A method for detecting the thickness of a co-cured panel functional layer and a non-destructive testing method

Abstract

The present application relates to the technical field of composite material testing, in particular to a kind of co-cured plate piece function layer thickness detection method and nondestructive testing method, co-cured plate piece is formed by function layer and carbon fiber co-curing, and function layer is prepared by absorbent, resin and fiber composite;Thickness detection method includes: using bow method to carry out perpendicular reflectivity test, obtains the time-domain curve of co-cured plate piece;Identify and extract time-domain peak on time-domain curve;Obtain the time t1 of half of entire time-domain peak;Based on correction coefficient, electromagnetic wave propagation rate in air and t1 calculate the thickness of function layer.Through this thickness detection method and nondestructive testing method, more accurate function layer thickness measurement and reliable nondestructive testing result can be provided, so as to improve the overall performance and reliability of functional composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite material testing, in particular to a thickness detection method and non-destructive testing method for a functional layer of a co-cured panel. BACKGROUND

[0002] The functional layer is prepared by compounding absorbent, resin and fiber, and then the functional layer is co-cured with carbon fiber prepreg to prepare a structure / function integrated composite material, which is a common method for preparing functional composite materials at present. In this process, the thickness of the functional layer has a significant impact on the wave absorption performance of the final composite material. Therefore, accurately measuring the actual thickness of the functional layer in the co-cured panel is crucial to ensure its performance.

[0003] However, traditional thickness testing methods such as vernier caliper and screw micrometer can only measure the total thickness of the entire co-cured panel, and cannot directly obtain the specific thickness information of the functional layer. This makes it difficult to accurately evaluate the thickness of the functional layer and its impact on overall performance in practical applications.

[0004] In addition, traditional non-destructive testing (NDT) methods such as ultrasonic testing face many challenges when dealing with non-homogeneous materials. Due to the complex internal structure of these materials and the presence of multiple interfaces between different materials, the ultrasonic signal is prone to multiple peak interlacing, making it difficult to accurately determine the thickness of the functional layer inside the co-cured panel and whether there are defects. Specifically, ultrasonic testing will produce multiple reflections and refractions when encountering different phase interfaces within the material, causing signal interference and affecting the accuracy of the detection results.

[0005] In view of the above problems, the existing thickness detection and non-destructive testing technology cannot meet the needs of controlling the thickness and quality of the functional layer in the co-cured panel. SUMMARY

[0006] To solve the above technical problems, the present application provides a thickness detection method and non-destructive testing method for a functional layer of a co-cured panel, which can provide more accurate functional layer thickness measurement and reliable non-destructive testing results, thereby improving the overall performance and reliability of functional composite materials.

[0007] The present application is achieved by adopting the following technical solutions:

[0008] A thickness detection method for a functional layer of a co-cured panel, the co-cured panel being co-cured by a functional layer and carbon fiber, and the functional layer being prepared by compounding absorbent, resin and fiber; the thickness detection method specifically includes the following steps:

[0009] Step S1. Perform vertical reflectivity test using the bow method to obtain the time-domain curve of the co-cured panel;

[0010] Step S2. Identify and extract time-domain peaks from the time-domain curve;

[0011] Step S3. Obtain the time t1 of half of the entire time domain peak;

[0012] Step S4. Calculate the thickness of the functional layer using the following method:

[0013] h1 = t1 × kc;

[0014] In the formula, h1 is the thickness of the functional layer, c is the propagation speed of electromagnetic waves in the air, and k is the correction coefficient.

[0015] The absorbent is selected from at least one of electrical loss absorbent, magnetic loss absorbent, or dielectric loss absorbent; the resin is a composite resin, which is a mixture of at least two of epoxy resin, bismaleimide resin, and cyanate ester resin.

[0016] The fiber is aramid or quartz.

[0017] The preparation method of the co-cured board is as follows: an absorbent is added to the composite resin at a ratio of 10wt% to 90wt% to obtain a microwave absorbing resin; the microwave absorbing resin is combined with fibers to form a single-layer functional layer with a thickness of 0.1mm to 1mm; a functional layer prepreg with a thickness of 0.5mm to 8mm and a carbon fiber prepreg with a thickness of 2mm to 10mm are sequentially laid on the surface of the tooling, vacuum treatment is performed, the temperature is raised to 130℃ to 180℃, and the temperature is maintained for 4h to 8h to complete the co-curing molding and obtain the co-cured board.

[0018] The vacuum pressure during the vacuuming process is 5 bar to 9 bar.

[0019] Step S1 specifically refers to: placing the co-cured board with the functional layer facing upwards directly below the antenna horn of the bow-shaped tester, and acquiring the time-domain curve of the co-cured board.

[0020] The test frequency band for the antenna horn is 0.1GHz to 40GHz.

[0021] A non-destructive testing method for the functional layer of a co-cured board is based on the time-domain peak extracted from the thickness detection method of the functional layer of the co-cured board mentioned above; the non-destructive testing method specifically refers to: judging whether there are defects in the functional layer based on the morphology of the time-domain peak.

[0022] The method for judging defects is as follows: if there are main peaks and impurity peaks in the time domain, it is determined that there are layering defects inside the functional layer; if there are multiple burrs mixed in the time domain peak, it is determined that there are diffuse porosity defects in the functional layer.

[0023] When a layering defect exists within a functional layer, the location of the layering defect is:

[0024] h2=t2*kc,

[0025] In the formula, h2 is the distance of the layered defect from the surface of the upper surface, t2 is the horizontal coordinate distance of the main peak value and the impurity peak value in the time domain peak, c is the propagation rate of electromagnetic waves in air, and k is a correction coefficient.

[0026] Compared with the prior art, the beneficial effects of the present application are as follows:

[0027] 1、The present application combines the absorbent, resin and fiber to form a functional layer with electromagnetic wave absorption capability, and co-cures the functional layer with carbon fiber to obtain an integrated co-cured plate. The time difference of electromagnetic waves reflected on the surface and bottom surface of the wave-absorbing functional layer is used to test the vertical reflectivity of the co-cured plate by using the bow method, and the time domain response curve is obtained. By analyzing the time domain main reflection peak, the corresponding time value is extracted, and the propagation speed of electromagnetic waves in the medium is combined to realize high-precision nondestructive testing of the thickness of the functional layer without damaging the sample.

[0028] 2、In the present application, the synergistic effect of the absorbent and the resin helps to improve the accuracy of the functional layer thickness detection; by adjusting the addition proportion of the absorbent, the reflection and absorption characteristics of electromagnetic waves can be optimized to realize controllable adjustment of the detection accuracy.

[0029] 3、The functional layer prepared by the method has a single-layer thickness controlled in the range of 0.1mm~1mm, which is beneficial to flexible design of the functional layer thickness according to the wave-absorbing performance requirements, so as to realize controllable adjustment of the wave-absorbing frequency band and intensity.

[0030] 4、In the present application, the preparation method of the co-cured plate synchronously cures the wave-absorbing functional layer and the carbon fiber layer under the same process conditions, which improves the interfacial bonding strength and overall structural stability, and avoids the risk of interlayer defects caused by traditional step-by-step curing. At the same time, by accurately controlling the layer thickness and curing process parameters, the integrated design of structure bearing and wave-absorbing function is realized, and the production efficiency and material utilization rate are improved.

[0031] 5、In the present application, the test frequency band of the antenna horn is 0.1GHz~40GHz, covering a wide range from low-frequency microwave to high-frequency millimeter wave, which can meet the test requirements of various wave-absorbing materials in different application scenarios.

[0032] 6、The present application analyzes the morphological characteristics of the time domain peak in the time domain curve, uses the reflection characteristics of electromagnetic waves at the interface between the wave-absorbing functional layer and the gap or other defects to realize the nondestructive determination of the wave-absorbing functional layer. Not only can it effectively determine whether the wave-absorbing functional layer has structural defects, but also can provide detailed defect distribution information to ensure the overall quality and performance of the material. BRIEF DESCRIPTION OF DRAWINGS

[0033] The application will be described in further detail below with reference to the drawings and specific embodiments, in which:

[0034] Figure 1 A flowchart of the detection method of the application. DETAILED DESCRIPTION

[0035] Embodiment 1

[0036] As a basic embodiment of the application, the application includes a thickness detection method of a co-cured functional layer of a co-cured panel, the co-cured panel being co-cured by a functional layer and carbon fibers, the functional layer being prepared by compounding an absorbent, a resin and fibers. The thickness detection method specifically includes the following steps:

[0037] Step S1. Vertical reflectivity test is performed by using the bow method to obtain a time-domain curve of the co-cured panel.

[0038] Step S2. Time-domain peaks are identified and extracted on the time-domain curve.

[0039] Step S3. Time t1 of half of the entire time-domain peak is obtained. Specifically, the intersection points of the time-domain peak and the x-axis are t2 and t3, where t3>t2. The calculation method of t1 is as follows:

[0040] .

[0041] Step S4. The thickness of the functional layer is calculated according to the following method:

[0042] h1=t1×kc;

[0043] In the formula, h1 is the thickness of the functional layer, c is the propagation rate of electromagnetic waves in air, and k is a correction coefficient.

[0044] Embodiment 2

[0045] As a preferred embodiment of the application, the application includes a thickness detection method of a co-cured functional layer of a co-cured panel, the co-cured panel being co-cured by a functional layer and carbon fibers, the functional layer being prepared by compounding an absorbent, a resin and fibers. The absorbent is selected from at least one of electric loss absorbents, magnetic loss absorbents or dielectric loss absorbents. The resin is a composite resin, which is mixed by at least two of epoxy resin, bismaleimide resin and cyanate ester resin. The fibers are aramid or quartz.

[0046] The thickness detection method specifically includes the following steps:

[0047] Step S1. Obtain the time-domain curve of the co-cured panel by vertical reflectivity test using the bow-tie method. Specifically, place the functional layer of the co-cured panel upwards directly below the antenna horn of the bow-tie test instrument to collect the time-domain curve of the co-cured panel.

[0048] Step S2. Identify and extract the time-domain peak on the time-domain curve.

[0049] Step S3. Obtain the time t1 of half of the entire time-domain peak. Specifically, the intersection points of the time-domain peak and the x-axis are t2 and t3, where t3>t2. The calculation method of t1 is as follows:

[0050] .

[0051] Step S4. Calculate the thickness of the functional layer according to the following method:

[0052] h1=t1×kc;

[0053] In the formula, h1 is the thickness of the functional layer, c is the propagation rate of electromagnetic waves in air, and k is the correction coefficient.

[0054] Example 3

[0055] As another preferred embodiment of the present application, the present application comprises a thickness detection method for a functional layer of a co-cured panel, wherein the co-cured panel is co-cured by a functional layer and carbon fibers, and the functional layer is prepared by compounding an absorber, a resin, and fibers. The preparation method of the co-cured panel comprises: adding the absorber to the resin at a proportion of 10wt%-90wt% to obtain wave-absorbing resin. The wave-absorbing resin and the fibers are compounded to form a functional layer with a single-layer thickness of 0.1mm-1mm. The functional layer prepreg with a thickness of 0.5mm-8mm and the carbon fiber prepreg with a thickness of 2mm-10mm are sequentially laid on the surface of the tooling, vacuumized, heated to 130℃-180℃, and kept at the temperature for 4h-8h to complete the co-curing molding and obtain the co-cured panel.

[0056] The thickness detection method specifically comprises the following steps:

[0057] Step S1. Obtain the time-domain curve of the co-cured panel by vertical reflectivity test using the bow-tie method.

[0058] Step S2. Identify and extract the time-domain peak on the time-domain curve.

[0059] Step S3. Obtain the time t1 of half of the entire time-domain peak. Specifically, the intersection points of the time-domain peak and the x-axis are t2 and t3, where t3>t2. The calculation method of t1 is as follows:

[0060] .

[0061] Step S4. Calculate the thickness of the functional layer using the following method:

[0062] h1 = t1 × kc;

[0063] In the formula, h1 is the thickness of the functional layer, c is the propagation speed of electromagnetic waves in the air, and k is the correction coefficient.

[0064] Example 4

[0065] In another preferred embodiment of the present invention, the present invention includes a non-destructive testing method for the functional layer of a co-cured board, comprising: performing a vertical reflectivity test using the bow-shaped method to obtain the time-domain curve of the co-cured board; identifying and extracting time-domain peaks from the time-domain curve; and determining whether there are defects in the functional layer based on the morphology of the time-domain peaks: if the time-domain peaks contain a main peak and impurity peaks, it is determined that there are delamination defects inside the functional layer; if the time-domain peaks contain multiple burrs, it is determined that there are diffuse porosity defects in the functional layer.

[0066] Example 5

[0067] In another preferred embodiment of the present invention, the present invention includes a method for detecting the thickness of a functional layer of a co-cured board, wherein the co-cured board is formed by co-curing a functional layer and carbon fibers, and the functional layer is prepared by composite of an absorbent, a resin, and fibers. The absorbent is selected from at least one of electrical loss absorbers, magnetic loss absorbers, or dielectric loss absorbers. The resin is a composite resin, composed of at least two of epoxy resin, bismaleimide resin, and cyanate ester resin. The fibers are aramid or quartz.

[0068] The preparation method of the co-cured board is as follows: An absorbent is added to a composite resin at a ratio of 10wt% to 90wt% to obtain a microwave-absorbing resin. The microwave-absorbing resin is then combined with microwave-transparent fibers such as aramid and quartz to form a single-layer functional layer with a thickness of 0.1mm to 1mm. The thickness of the functional layer is set according to the microwave absorption characteristics. A functional layer prepreg with a thickness of 0.5mm to 8mm and a carbon fiber prepreg with a thickness of 2mm to 10mm are sequentially laid on the surface of the tooling. Vacuum treatment is performed, and the temperature is raised to 130℃ to 180℃ and held at this temperature for 4h to 8h to complete the co-curing process and obtain the co-cured board. The vacuum pressure during the vacuum treatment is 5bar to 9bar.

[0069] The thickness detection method specifically includes the following steps:

[0070] Step S1. Perform vertical reflectivity testing using the bow-shaped method to obtain the time-domain curve of the co-cured board. Specifically, place the functional layer of the co-cured board upwards directly below the antenna horn of the bow-shaped method tester, and collect the time-domain curve of the co-cured board. The test frequency band of the antenna horn is 0.1GHz~40GHz.

[0071] Step S2. Identify and extract time-domain peaks from the time-domain curve.

[0072] Step S3. Obtain the time t1 of half the entire time-domain peak. Specifically, the intersection points of the time-domain peak and the x-axis are t2 and t3, where t3 > t2. The calculation method for t1 is as follows:

[0073] .

[0074] Step S4. Calculate the thickness of the functional layer using the following method:

[0075] h1 = t1 × kc;

[0076] In the formula, h1 is the thickness of the functional layer. c is the propagation speed of electromagnetic waves in air, 3 × 10⁻⁶. 8 m / s. k is a correction factor that adjusts the transmission efficiency of electromagnetic waves in the medium.

[0077] The different distances between the reflected electromagnetic waves from the upper and lower surfaces of the functional layer and the antenna horn result in different losses, forming a peak on the time-domain curve. The electromagnetic wave at the top of the peak represents the electromagnetic wave rate reflected from the upper surface of the plate, and is closest to the horn. The electromagnetic wave at the bottom of the peak represents the electromagnetic wave interference at the interface between the functional layer and the carbon fiber layer, and is closest to the horn. The thickness of the absorbing functional layer can be obtained by the difference between these two values ​​on the horizontal axis and the propagation rate of the electromagnetic wave in the material. This thickness detection method is compatible with all materials with electromagnetic wave loss characteristics, and therefore can test any co-cured product with electromagnetic wave loss, including electrical loss materials, magnetic loss materials, dielectric loss materials, and composite materials of two or more types.

[0078] Based on the time-domain peaks extracted using the aforementioned detection methods, non-destructive testing of the functional layers of co-cured boards can be performed. Specifically, the morphology of the time-domain peaks can be used to determine whether defects exist in the functional layer. If multiple peaks are present in the time-domain peaks, including the main peak and impurity peaks, it is determined that there are delamination defects within the functional layer; if multiple burrs are mixed in the time-domain peaks, it is determined that there are diffuse porosity defects in the functional layer. Due to the multiple scattering characteristics of electromagnetic waves at interfaces, if multiple interfaces exist in the material, the propagation speed of electromagnetic waves within them will vary significantly, thus resulting in impurity peaks or burrs appearing in the time-domain curve.

[0079] When a layering defect exists within a functional layer, the location of the layering defect is:

[0080] h2 = t2 × kc,

[0081] In the formula, h2 is the distance from the layered defect to the upper surface, t2 is the abscissa distance between the main peak and the impurity peak in the time domain, and c is the propagation speed of electromagnetic waves in air, 3 × 10⁻⁶. 8m / s. k is a correction coefficient, revising the transmission efficiency of electromagnetic wave in medium.

[0082] Example 6

[0083] As a specific embodiment of the present application, the magnetic loss absorber is selected as carbonyl iron, 80 phr of carbonyl iron is compounded with 20 phr of high-temperature epoxy resin to form a high-temperature epoxy wave-absorbing resin, the high-temperature epoxy wave-absorbing resin is prepared into a resin adhesive film by using a double roller, and the resin adhesive film is compounded with aramid fiber to prepare a wave-absorbing functional layer with a single-layer thickness of 0.2 mm. Four layers of wave-absorbing functional layers and 25 layers of carbon fiber prepreg with a single-layer thickness of 0.1 mm are sequentially laid on the surface of a tooling. After being pressurized to 6 bar and heated to 160°C for 5 h, a co-cured plate part is obtained. The time-domain curve of the co-cured plate part is tested by using an arch method vertical reflectivity testing instrument, and the time of the whole time-domain peak is measured to be 5.84×10 -9 s, t1 is 2.92×10 -9 s, and the correction coefficient k of electromagnetic wave in the wave-absorbing prepreg is measured to be 0.86. The thickness of the wave-absorbing functional layer is calculated to be 0.75 mm.

[0084] The test precision of the present example is 0.01 mm, the time-domain curve does not appear to have a spur and burr, and the surface quality of the wave-absorbing functional layer is good.

[0085] Example 7

[0086] As a specific embodiment of the present application, 80 phr of carbonyl iron is compounded with 20 phr of high-temperature epoxy resin to form a high-temperature epoxy wave-absorbing resin, the high-temperature epoxy wave-absorbing resin is prepared into a resin adhesive film by using a double roller, and the resin adhesive film is compounded with aramid fiber to prepare a wave-absorbing functional layer with a single-layer thickness of 0.2 mm. Four layers of wave-absorbing functional layers and 25 layers of carbon fiber prepreg with a single-layer thickness of 0.1 mm are sequentially laid on the surface of a tooling. After being pressurized to 6 bar and heated to 160°C for 5 h, a co-cured plate part is obtained. The time-domain curve of the co-cured plate part is tested by using an arch method vertical reflectivity testing instrument, and the time of the whole time-domain peak is measured to be 1.53×10 -8 s, t1 is 0.765×10 -8 s, and the correction coefficient k of electromagnetic wave in the wave-absorbing prepreg is measured to be 0.86. The thickness of the wave-absorbing functional layer is calculated to be 1.970 mm.

[0087] The test precision of the present example is 0.01 mm, the time-domain curve does not appear to have a spur and burr, and the surface quality of the wave-absorbing functional layer is good.

[0088] Example 8

[0089] As a specific embodiment of the present application, 60 phr of carbonyl iron is compounded with 40 phr of high-temperature epoxy resin to form a high-temperature epoxy wave-absorbing resin, the high-temperature epoxy wave-absorbing resin is prepared into a resin adhesive film by using a double roller, and the resin adhesive film is compounded with aramid fiber to prepare a wave-absorbing functional layer with a single-layer thickness of 0.2 mm. On the surface of a tool, 15 layers of the wave-absorbing functional layer and 25 layers of carbon fiber prepreg with a single-layer thickness of 0.1 mm are sequentially laid and stacked. After being pressurized at 6 bar and heated to 160 °C for 5 h, a co-cured plate part is obtained. The time-domain curve of the co-cured plate part is tested by using an arch method vertical reflectivity testing instrument with the functional layer upward, and it is measured that the time of the entire time-domain peak is 2.15 x 10 -8 s, t1 is 1.075 x 10 -8 s, and the correction coefficient k of the electromagnetic wave in the wave-absorbing prepreg is 0.91, and the thickness of the wave-absorbing functional layer is calculated to be 2.93 mm.

[0090] The test precision of this embodiment is 0.03 mm, the time-domain curve does not appear a spur and burr, and the surface quality of the wave-absorbing functional layer is good.

[0091] Example 9

[0092] As a specific embodiment of the present application, 60 phr of carbonyl iron is compounded with 40 phr of high-temperature epoxy resin to form a high-temperature epoxy wave-absorbing resin, the high-temperature epoxy wave-absorbing resin is prepared into a resin adhesive film by using a double roller, and the resin adhesive film is compounded with aramid fiber to prepare a wave-absorbing functional layer with a single-layer thickness of 0.2 mm. On the surface of a tool, 15 layers of the wave-absorbing functional layer and 25 layers of carbon fiber prepreg with a single-layer thickness of 0.1 mm are sequentially laid and stacked. After being pressurized at 6 bar and heated to 160 °C for 5 h, a co-cured plate part is obtained. The time-domain curve of the co-cured plate part is tested by using an arch method vertical reflectivity testing instrument with the functional layer upward, and it is measured that the time of the entire time-domain peak is 2.15 x 10 -9 s, and the correction coefficient k of the electromagnetic wave in the wave-absorbing prepreg is 0.91, and the thickness of the wave-absorbing functional layer is calculated to be 2.93 mm.

[0093] The test precision of this embodiment is 0.01 mm.

[0094] Example 10

[0095] As a specific embodiment of the present application, 60 phr of carbonyl iron is compounded with 40 phr of high-temperature epoxy resin to form a high-temperature epoxy wave-absorbing resin. The high-temperature epoxy wave-absorbing resin is prepared into a resin adhesive film by using a double roller, and is compounded with aramid fiber to prepare a single-layer wave-absorbing functional layer with a thickness of 0.2 mm. Four layers of the wave-absorbing functional layer and 25 layers of carbon fiber prepreg with a single-layer thickness of 0.1 mm are sequentially laid on the surface of a tooling. After being pressurized to 6 bar, heated to 160°C, and cured for 5 h, a co-cured plate part is obtained. The time-domain curve of the functional layer of the co-cured plate part is tested by using an arch-shaped reflectivity testing instrument, and it is measured that the time of the entire time-domain peak is 5.41 x 10 -9 s, t1 is 2.705 x 10 -9 s, and the correction coefficient k of the electromagnetic wave in the wave-absorbing prepreg is 0.91, and the thickness of the wave-absorbing functional layer is calculated to be 0.74 mm.

[0096] The test precision of the present embodiment is 0.03 mm, the time-domain curve does not appear to have a spur and burr, and the surface quality of the wave-absorbing functional layer is good.

[0097] Therefore, the actual thickness of the functional layer of the co-cured plate part is successfully measured in a non-destructive manner by using the time-domain curve, and the non-destructive defect detection and position determination are realized.

[0098] In summary, after reading the present application document, the person skilled in the art can make various corresponding transformation schemes according to the technical solutions and technical concepts of the present application without creative mental labor, which all belong to the scope of protection of the present application.

Claims

1. A method for detecting the thickness of a co-cured panel functional layer, characterized in that: The co-cured board is formed by co-curing a functional layer and carbon fiber. The functional layer is prepared by combining an absorbent, resin, and fiber. The absorbent is selected from at least one of electrical loss absorbent, magnetic loss absorbent, or dielectric loss absorbent. The resin is a composite resin, composed of at least two of epoxy resin, bismaleimide resin, and cyanate ester resin. The thickness detection method specifically includes the following steps: Step S1. Use the bow-shaped method to perform vertical reflectivity testing and obtain the time-domain curve of the co-cured board; Step S2. Identify and extract time-domain peaks from the time-domain curve; Step S3. Obtain the time t1 of half of the entire time domain peak; Step S4. Calculate the thickness of the functional layer using the following method: ， ； In the formula, h1 is the thickness of the functional layer, c is the propagation speed of electromagnetic waves in air, t2 and t3 are the intersection points of the time domain peak and the x-axis, respectively; k is the correction coefficient, which corrects the transmission efficiency of electromagnetic waves in the medium. The correction coefficient k is related to the absorbent content. Step S1 specifically refers to: placing the co-cured board with the functional layer facing upwards directly below the antenna horn of the bow-shaped tester, and acquiring the time-domain curve of the co-cured board. The test frequency band of the antenna horn is 0.1GHz~40GHz.

2. The method of claim 1, wherein: The fiber is aramid or quartz.

3. A method of detecting the thickness of a functional layer of a co-cured panel member according to claim 1 or 2, characterized in that: The preparation method of the co-cured board is as follows: an absorbent is added to the composite resin at a ratio of 10wt% to 90wt% to obtain a microwave absorbing resin; the microwave absorbing resin is combined with fibers to form a single-layer functional layer with a thickness of 0.1mm to 1mm; a functional layer prepreg with a thickness of 0.5mm to 8mm and a carbon fiber prepreg with a thickness of 2mm to 10mm are sequentially laid on the surface of the tooling, vacuum treatment is performed, the temperature is raised to 130℃ to 180℃, and the temperature is maintained for 4h to 8h to complete the co-curing molding and obtain the co-cured board.

4. The method of claim 3, wherein the thickness of the functional layer of the co-cured panel member is detected. The vacuum pressure during the vacuuming process is 5 bar to 9 bar.

5. A method of non-destructive testing of co-cured panel functional layers, characterized in that: It is based on the time-domain peak extracted from the thickness detection method of the co-cured board functional layer as described in claim 1; the non-destructive testing method specifically refers to: judging whether there are defects in the functional layer based on the morphology of the time-domain peak.

6. A method of non-destructive testing of a function layer of a co-cured panel according to claim 5, characterized in that: The method for judging defects is as follows: if there are main peaks and impurity peaks in the time domain, it is determined that there are layering defects inside the functional layer; if there are multiple burrs mixed in the time domain peak, it is determined that there are diffuse porosity defects in the functional layer.

7. A method of non-destructive testing of a co-cured panel component functional layer according to claim 6, characterized in that: When a layering defect exists within a functional layer, the location of the layering defect is: ， In the formula, h2 is the distance from the layered defect to the upper surface, t2 is the abscissa distance between the main peak and the impurity peak in the time domain peak, c is the propagation speed of electromagnetic waves in air, and k is the correction coefficient.

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