Method for evaluating cutting damage of CFRP member based on pore characteristics and predicting interlaminar performance

Abstract

The present application relates to the technical field of composite material cutting, and particularly relates to a CFRP component cutting damage evaluation and interlaminar performance prediction method based on pore characteristics, which establishes a comprehensive structure damage evaluation index calculation model and an interlaminar shear strength prediction model. The coefficients of the comprehensive structure damage evaluation index calculation model are calibrated based on multi-dimensional pore parameters and measured interlaminar shear strength of the target CFRP component under multiple groups of different cutting parameters. After the multi-dimensional pore parameters of the CFRP component to be measured are normalized and input into the comprehensive structure damage evaluation index calculation model, the comprehensive structure damage evaluation index of the CFRP component to be measured can be obtained; then the comprehensive structure damage evaluation index is input into the interlaminar shear strength prediction model, and the interlaminar shear strength prediction value of the CFRP component to be measured can be obtained. The method of the present application can comprehensively reflect the damage state of the CFRP subsurface layer after cutting, and accurately predict the interlaminar shear strength of the CFRP after cutting.

Description

Technical Field

[0001] This invention relates to the field of composite material machining technology, and in particular to a method for evaluating cutting damage and predicting interlayer properties of CFRP components based on pore characteristics. Background Technology

[0002] Carbon fiber reinforced polymer (CFRP) is composed of high-strength carbon fibers, a resin matrix, and fiber / resin interfaces. During machining, the mechanical compression and thermo-mechanical coupling between the tool and the material can easily induce various machining damages, including fiber breakage, matrix cracking, and localized delamination. These damages not only exist on the machined surface but also extend into the subsurface region, further weakening the interlaminar load-bearing capacity of CFRP and affecting the service life of CFRP components. Therefore, it is necessary to evaluate the machining damage of CFRP to assess CFRP components and optimize process parameters.

[0003] In existing technologies, CFRP cutting damage evaluation methods mainly fall into two categories. The first category is online evaluation methods based on machining process signals, such as establishing machining quality prediction models using machining process signals like cutting force, cutting temperature, and vibration for damage evaluation. While these methods can reflect the machining process state, they typically rely on complex sensor systems and signal acquisition platforms, resulting in high costs in actual production environments. Furthermore, there is an indirect relationship between machining process signals and the final interlayer mechanical properties, making it difficult to directly reflect the impact of internal material defects on interlayer load-bearing capacity. The second category is detection and evaluation methods based on post-machining damage results, such as evaluating machining quality through scanning electron microscopy, ultrasonic testing, and X-ray inspection. These methods can directly observe or detect material damage, but they are mostly qualitative observations or single-index evaluation methods, failing to comprehensively reflect the damage state of the CFRP subsurface after machining.

[0004] Furthermore, interlaminar shear strength (ILSS) is an effective criterion for evaluating the degree to which cutting damage in CFRP weakens its interlaminar load-bearing capacity. For CFRP ILSS, degradation depends not only on the total amount of porosity but also on the complexity of the pore network, the pore size distribution, and the proportion of large-scale defects. Macropores, interconnected pores, and crack-like pores are prone to becoming the initiation points of interlaminar shear failure, while complex pore networks disrupt the continuous load-bearing path at the resin matrix-fiber interface. Therefore, existing methods that rely solely on single-dimensional indicators such as porosity, pore structure fractal dimension, or surface quality to determine ILSS cannot accurately and comprehensively establish a direct quantitative correlation between cutting-induced subsurface damage and interlaminar load-bearing capacity, leading to significant deviations in the final determined ILSS. Summary of the Invention

[0005] Therefore, it is necessary to provide a method for evaluating cutting damage and predicting interlayer properties of CFRP components based on pore characteristics to address the above-mentioned technical problems. This method can comprehensively reflect the damage state of the CFRP subsurface after cutting and accurately predict the interlayer shear strength of CFRP after cutting.

[0006] This invention provides a method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics, comprising the following steps: The multidimensional pore parameters and measured interlaminar shear strength of the target CFRP component under multiple sets of different cutting parameters were obtained. The multidimensional pore parameters include total porosity, fractal dimension of pore structure and proportion of dangerous large pores. Dimensionless damage characteristics are obtained by normalizing the porosity parameters of each dimension under each set of cutting parameters. The interlayer shear strength loss rate is calculated based on the measured interlayer shear strength under each set of cutting parameters. A correlation model between dimensionless damage characteristics and interlaminar shear strength loss rate was constructed, and the coefficients of the correlation model between dimensionless damage characteristics and interlaminar shear strength loss rate were calibrated based on the dimensionless damage characteristics and interlaminar shear strength loss rate under each set of cutting parameters. A comprehensive structural damage evaluation index calculation model was constructed, and the coefficients of the comprehensive structural damage evaluation index calculation model were back-calculated based on the coefficients of the correlation model between dimensionless damage characteristics and interlaminar shear strength loss rate. A prediction model for interlaminar shear strength was established based on comprehensive structural damage evaluation indicators. After obtaining the multi-dimensional porosity parameters of the CFRP component under test, normalizing them, and inputting them into the comprehensive structural damage evaluation index calculation model, the comprehensive structural damage evaluation index of the CFRP component under test is obtained. By inputting the comprehensive structural damage evaluation index into the interlaminar shear strength prediction model, the predicted value of the interlaminar shear strength of the CFRP member under test is obtained.

[0007] The beneficial effects of this invention are: (1) This invention overcomes the shortcomings of existing single-index evaluation methods for cutting damage. It integrates three dimensions of characteristics—total porosity, pore structure fractal dimension, and proportion of dangerous large pores—into the evaluation system, establishes a comprehensive structural damage evaluation index calculation model, realizes the fusion of multi-dimensional pore characteristics, and calculates the comprehensive structural damage index. The comprehensive structural damage evaluation index can fully reflect the damage state of the CFRP subsurface after cutting. (2) The present invention establishes an interlaminar shear strength prediction model based on comprehensive structural damage evaluation index. The three dimensions of data, namely total porosity, pore structure fractal dimension and proportion of dangerous large pores, are all correlated with interlaminar shear strength at the same time. This can accurately and comprehensively establish a direct quantitative correlation between subsurface damage and interlaminar bearing capacity, so that the predicted interlaminar shear strength has a high accuracy. (3) This invention achieves cutting damage evaluation and interlaminar shear strength prediction by obtaining multi-dimensional porosity parameters of the CFRP component to be tested after cutting, which can effectively reduce evaluation costs and more directly reflect the influence of internal material defects on interlaminar load-bearing capacity. (4) The present invention does not require shear testing to determine the interlaminar shear strength of the CFRP component to be tested. It can quickly predict the interlaminar shear strength using the comprehensive structural damage evaluation index obtained by the cutting damage evaluation while using multi-dimensional pore parameters for cutting damage evaluation, thereby improving the efficiency of determining the interlaminar shear strength of the CFRP component to be tested. Attached Figure Description

[0008] Figure 1 This is a flowchart illustrating a method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics, provided in an embodiment of the present invention. Detailed Implementation

[0009] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0010] To address the shortcomings of existing technologies that use single-dimensional indicators to evaluate the cutting damage of CFRP components, failing to comprehensively reflect the damage state of the CFRP subsurface after machining, and the inaccuracy of using single-dimensional indicators to determine interlaminar shear strength, this invention constructs a comprehensive structural damage evaluation index calculation model using multi-dimensional porosity parameters. This comprehensive structural damage evaluation index is then used to evaluate the cutting damage of CFRP components. Simultaneously, a prediction model for interlaminar shear strength is established using this comprehensive structural damage evaluation index, thereby further obtaining predicted values ​​of interlaminar shear strength.

[0011] The method of this invention constructs a structural damage evaluation index calculation model based on multi-dimensional porosity parameters, which can comprehensively reflect the damage state of the CFRP subsurface after machining and improve the prediction accuracy of interlaminar shear strength. Furthermore, the method of this invention constructs a comprehensive structural damage evaluation index calculation model based on the same type of target CFRP component produced using the same material system and manufacturing process as the CFRP component under test. This comprehensive structural damage evaluation index calculation model can detect cutting damage in the same type of CFRP component during the production process, and the interlaminar shear strength prediction model can also predict the interlaminar shear strength of the same type of CFRP component during the production process, providing direct basis for CFRP component processing quality grading, process parameter optimization, product acceptance, and service reliability assessment.

[0012] The specific method of this invention is as follows: In one embodiment, such as Figure 1 As shown in the figure, the method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics in this embodiment includes the following steps: S10. Obtain multi-dimensional pore parameters and measured interlaminar shear strength of the target CFRP component under multiple sets of different cutting parameters.

[0013] Specifically, multidimensional pore parameters include total porosity, fractal dimension of pore structure, and proportion of dangerous macropores.

[0014] Total porosity was obtained using mercury intrusion porosimetry, microscopic image analysis, or X-ray micro-CT. The fractal dimension of the pore structure was calculated using pore size distribution curves, mercury intrusion pressure-pore volume curves, scanning electron microscopy images, or binarized pore images. The proportion of critical macropores was determined based on pore size distribution data; pores with a diameter larger than a preset critical pore size threshold were defined as critical macropores, and the proportion of critical macropores was the ratio of the volume of the corresponding critical macropore to the total pore volume.

[0015] When the pore size distribution data is pore volume increment data, the proportion of dangerous large pores is calculated using the following formula: In the formula, For the first The aperture corresponding to each aperture range For the first The pore volume increment corresponding to each pore size range This is a preset threshold for dangerous apertures.

[0016] Specifically, a preset hazardous aperture threshold d c The specific threshold for critical pore size (d) can be determined based on the specific CFRP material system, resin type, fiber volume fraction, layup structure, service requirements, and the correlation between the proportion of critical macropores and the interlaminar shear strength loss rate. For example, a preset critical pore size threshold d can be used.c The sizes are 10μm, 50μm, or 100μm.

[0017] When the pore size distribution data is the same as the pore volume distribution density data, the proportion of dangerous macropores is calculated using the following formula: In the formula, aperture The corresponding pore volume distribution density, and These represent the lower and upper limits of the aperture testing range, respectively.

[0018] S20. Normalize the pore parameters of each dimension under each set of cutting parameters to obtain dimensionless damage characteristics.

[0019] In this embodiment, the porosity parameters of each dimension under each set of cutting parameters are normalized using a reference CFRP component sample. The reference CFRP component sample is an uncut or low-damage CFRP component.

[0020] The formula for normalizing the total porosity is as follows: In the formula, This represents the normalized porosity factor of the target CFRP component. This represents the total porosity of the target CFRP component. This represents the total porosity of the reference CFRP component sample. This represents the maximum total porosity of the target CFRP component under multiple sets of different cutting parameters.

[0021] The formula for normalizing the fractal dimension of the pore structure is as follows: In the formula, This represents the normalized pore complexity factor of the target CFRP component. This represents the fractal dimension of the pore structure of the target CFRP component. This represents the fractal dimension of the pore structure of the reference CFRP component sample. This represents the maximum value of the fractal dimension of the pore structure of the target CFRP component under multiple sets of different cutting parameters.

[0022] The formula for normalizing the proportion of dangerous macropores is as follows: In the formula, This represents the normalized critical hole size factor of the target CFRP component. This indicates the proportion of dangerous large holes in the target CFRP component. This indicates the percentage of hazardous large holes in the reference CFRP component sample. This represents the maximum percentage of critical large holes in the target CFRP component under multiple sets of different cutting parameters.

[0023] The normalized pore quantity factor, normalized pore complexity factor, and normalized critical hole size factor of the target CFRP component under each set of cutting parameters constitute the dimensionless damage characteristics of the target CFRP component under each set of cutting parameters.

[0024] Normalization can obtain dimensionless damage characteristics with consistent direction, eliminate the problem of inconsistent dimensions and numerical ranges of different pore structure parameters, avoid the distortion of indicators caused by direct linear superposition, and improve the comparability and stability of cutting damage indicators.

[0025] S30. Calculate the interlaminar shear strength loss rate based on the measured interlaminar shear strength under each set of cutting parameters.

[0026] Specifically, the formula for calculating the interlaminar shear strength loss rate is: In the formula, Indicates the first Interlaminar shear strength loss rate of the target CFRP component under a set of cutting parameters. Indicates the first Measured interlaminar shear strength of the target CFRP component under a set of cutting parameters. This represents the measured interlaminar shear strength of the reference CFRP component sample. Indicates the first Interlaminar shear strength retention rate of the target CFRP component under a set of cutting parameters.

[0027] S40. Construct a correlation model between dimensionless damage characteristics and interlaminar shear strength loss rate, and calibrate the coefficients of the correlation model between dimensionless damage characteristics and interlaminar shear strength loss rate based on the dimensionless damage characteristics and interlaminar shear strength loss rate under each set of cutting parameters.

[0028] In this embodiment, a correlation model between dimensionless damage characteristics and interlaminar shear strength loss rate is constructed using dimensionless damage characteristics as the independent variable and interlaminar shear strength loss rate as the dependent variable. This correlation model is as follows: In the formula, Indicates the first Interlaminar shear strength loss rate of the target CFRP component under a set of cutting parameters. , and They represent the first Normalized pore quantity factor, normalized pore complexity factor, and normalized critical hole size factor of the target CFRP component under the set cutting parameters. , and These are the contribution coefficients of the normalized pore quantity factor, normalized pore complexity factor, and normalized dangerous pore size factor to the interlaminar shear strength loss rate, respectively.

[0029] Specifically, , and The calibration includes, but is not limited to, least squares method and multiple regression analysis. By using the method of calibrating coefficients from test data, the subjectivity of manually setting weights is avoided, which can improve the applicability of the method of the present invention under different material batches and different processing conditions.

[0030] S50. Construct a comprehensive structural damage evaluation index calculation model, and back-calculate the coefficients of the comprehensive structural damage evaluation index calculation model based on the coefficients of the correlation model between dimensionless damage characteristics and interlaminar shear strength loss rate.

[0031] Specifically, the calculation model for the comprehensive structural damage evaluation index is as follows:

[0032] In the formula, This represents the comprehensive structural damage evaluation index. , and These represent the normalized pore quantity factor, normalized pore complexity factor, and normalized critical pore size factor of the CFRP component under test, respectively. , and These represent the weighting coefficients of the normalized porosity factor, normalized porosity complexity factor, and normalized critical pore size factor of the CFRP component under test, respectively. .

[0033] in, In the formula, This represents the sensitivity coefficient to interlaminar shear strength degradation.

[0034] S60. Establish an interlaminar shear strength prediction model based on comprehensive structural damage evaluation index.

[0035] Specifically, the interlaminar shear strength prediction model is as follows: In the formula, This represents the predicted interlaminar shear strength of the CFRP member to be tested. The interlaminar shear strength is used as a reference CFRP component sample.

[0036] The interlaminar shear strength prediction model in this embodiment is based on a comprehensive structural damage evaluation index. It can further predict the interlaminar shear strength after the damage evaluation of the CFRP component under test, so that the damage evaluation results can be quickly converted into interlaminar shear strength prediction results.

[0037] S70. After obtaining the multi-dimensional porosity parameters of the CFRP component to be tested, normalize them, and input them into the comprehensive structural damage evaluation index calculation model to obtain the comprehensive structural damage evaluation index of the CFRP component to be tested.

[0038] The CFRP component under test and the target CFRP component were prepared using the same CFRP material system and manufacturing process. It should be noted that the pore parameters of each dimension of the CFRP component under test were obtained using the same detection and calculation methods as in the model calibration stage. Furthermore, the pore parameter normalization process was the same as in step S20, and the maximum values ​​of the pore parameters used were equal to the baseline parameters.

[0039] The target CFRP component is used to obtain model calibration data, while the CFRP component under test is the object for evaluating cutting damage and predicting interlaminar shear strength after the model calibration is completed.

[0040] S80. Input the comprehensive structural damage evaluation index into the interlaminar shear strength prediction model to obtain the predicted value of the interlaminar shear strength of the CFRP component to be tested.

[0041] The method for evaluating cutting damage and predicting interlaminar performance of CFRP components based on pore characteristics in this embodiment unifies three types of characteristics—pore quantity, pore complexity, and critical pore size—into a comprehensive structural damage index. In this study, the damage state of the subsurface layer of CFRP after machining can be more comprehensively reflected from the perspective of multi-scale pore structure, and is based on a comprehensive structural damage index. It can quickly predict interlaminar shear strength.

[0042] It should be noted that if the cutting damage to be evaluated and the CFRP component for predicting interlaminar performance change, the method of this invention needs to be used to re-establish the comprehensive structural damage evaluation index calculation model and the interlaminar shear strength prediction model of the CFRP component to be tested.

[0043] In one embodiment, the method for evaluating cutting damage and predicting interlaminar performance of CFRP components based on pore characteristics further includes determining the damage level of the CFRP component under test based on a comprehensive structural damage evaluation index calculation model, specifically: when When the damage is less than the first threshold, the CFRP component under test is determined to be slightly damaged. When the damage is greater than or equal to the first threshold and less than the second threshold, the CFRP component under test is determined to have moderate damage. If the damage is greater than or equal to the second threshold, the CFRP component under test is determined to be severely damaged, where the first threshold is less than the second threshold.

[0044] In this embodiment, the first threshold and the second threshold can be determined based on the calibration sample. The distribution, the rate of decrease in interlaminar shear strength retention, and the engineering acceptance standards or service safety requirements are determined.

[0045] In one specific embodiment, a CFRP multidirectional laminate prepared by hot-pressing and curing T700 carbon fiber prepreg is used as the object for evaluating cutting damage, further illustrating the method of the present invention.

[0046] In this embodiment, the CFRP multidirectional laminate has a fiber volume fraction of 58% and a density of 1.58 g / cm³. 3 The total thickness is 4.4mm.

[0047] The CFRP side milling test was completed on an XKH800 five-axis vertical machining center. The cutting tool used was a 10mm diameter, 4-tooth carbide flat end mill. All cutting processes were dry cutting, with an axial depth of cut of 4.4mm (through machining along the plate thickness) and a radial depth of cut of 1.0mm.

[0048] In this embodiment, an uncut original sample, denoted as P0, is used as the reference CFRP component sample to characterize the initial pore structure and intrinsic interlaminar shear properties of the material when it is not disturbed by processing. Four specimens of the same specifications as the reference CFRP component sample are cut from the same CFRP multidirectional laminate and denoted as A, B, C, and D. Cutting experiments are performed on specimens A, B, C, and D using different cutting parameters. The four identical specimens A, B, C, and D exhibit typical processing damage states under different cutting loads and thermal effects.

[0049] All samples in this embodiment were cut from the same batch of laminates, which reduces the impact of batch differences in materials on the evaluation of cutting damage and the prediction of interlaminar properties. The cutting parameters and damage states of samples P0, A, B, C, and D are shown in Table 1.

[0050] Table 1. Cutting parameters and damage states of various CFRP multidirectional laminate samples.

[0051] The method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics in this embodiment includes the following steps: (1) Obtain the multidimensional pore parameters and measured interlaminar shear strength of each sample. In this embodiment, the AutoPore IV 9500 fully automatic mercury porosimeter was used to obtain the cumulative mercury ingress curve and pore size distribution data of the sample, and the total porosity, the proportion of dangerous macropores and the fractal dimension of pore structure were calculated accordingly.

[0052] In this embodiment, the aperture is larger than the preset dangerous aperture threshold d. c The porosity is defined as a dangerous large pore. Considering the correlation between different pore size thresholds and interlayer shear strength loss rate, as well as the destructive effect of large-scale pore defects on the interlayer bearing path, this embodiment preferably... .

[0053] Room temperature short beam shear tests were conducted on samples P0, A, B, C, and D using a Sansi Zongheng UTM5105GD universal testing machine, according to JC / T 773 standard. The sample dimensions were 44.0 mm × 22.0 mm × 4.4 mm. Load-displacement curves were recorded using a three-point bending loading method, and interlaminar shear strength was calculated from the maximum load. The average of multiple effective interlaminar shear strengths for each CFRP multi-directional laminate sample was taken as the measured interlaminar shear strength for that sample. The retention rate and loss rate of interlaminar shear strength for A, B, C, and D were calculated. The pore structure parameters and interlaminar shear strength test results for each CFRP multi-directional laminate sample are shown in Table 2.

[0054] Table 2. Pore structure parameters and interlaminar shear strength test results of CFRP multidirectional laminate samples.

[0055] Table 2 shows that, compared to the baseline CFRP component sample P0, samples A, B, C, and D exhibited varying degrees of interlaminar shear strength loss after machining. This result indicates that different machining conditions induced varying degrees of internal structural damage, providing a data foundation for establishing the mapping relationship between pore structure damage indices and interlaminar performance degradation.

[0056] (2) Using the reference total porosity of the reference CFRP component sample P0 fractal dimension of the reference pore structure and the proportion of critical large holes The pore parameters for each dimension of A, B, C, and D were normalized. The normalization results are shown in Table 3.

[0057] Table 3 Normalized results of pore structure characteristics of CFRP samples Through the above normalization process, pore structure parameters with different dimensions and numerical ranges are converted into dimensionless damage characteristics with consistent orientation. Among them, Characterizing the number and degree of damage to pores, Characterizing the complexity of pore networks, Characterizes the degree of damage at the critical pore scale.

[0058] (3) Based on the data in Tables 2 and 3, the coefficients of the correlation model between dimensionless damage characteristics and interlaminar shear strength loss rate were calibrated and determined. , , .

[0059] Further calculation of the interlaminar shear strength degradation sensitivity coefficient: And calculate the comprehensive structural damage index. Weighting coefficients in: Therefore, we can conclude that: The specific calculation model for the comprehensive structural damage evaluation index is as follows: Among them, porosity represents the number of defects caused by cutting damage, the fractal dimension of the pore structure represents the complexity and irregularity of the pore network, and the proportion of dangerous large pores represents the potential destructive capacity of large-scale defects to the interlayer bearing path. A comprehensive structural damage index is formed by weighting these three factors. It can simultaneously reflect the extent of damage, the complexity of damage, and the scale of dangerous defects, thus comprehensively reflecting the damage state of the CFRP subsurface after machining.

[0060] In this embodiment, to illustrate the damage grading process, a first threshold is used. Second threshold .

[0061] when At that time, it was determined to be a minor injury; when At that time, it was determined to be a moderate injury; when At that time, it was determined to be a serious injury.

[0062] (4) The interlaminar shear strength prediction model finally established in this embodiment is as follows: To demonstrate the high accuracy of the interlaminar shear strength prediction model in this embodiment, the interlaminar shear strength of samples A, B, C, and D was predicted using the aforementioned model, and compared with the measured interlaminar shear strength in Table 2. The comparison results of the predicted and measured interlaminar shear strength values ​​for samples A, B, C, and D of the CFRP multidirectional laminate are shown in Table 4.

[0063] Table 4. Evaluation results of cutting damage for each sample and comparison of predicted and measured interlaminar shear strength values. As shown in Table 4, the relative error between the prediction results of the interlaminar shear strength prediction model and the measured interlaminar shear strength of each sample in this embodiment is small, proving that the method of the present invention has high accuracy in predicting the interlaminar shear strength after CFRP cutting.

[0064] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics, characterized in that, Includes the following steps: The multidimensional pore parameters and measured interlaminar shear strength of the target CFRP component under multiple sets of different cutting parameters are obtained. The multidimensional pore parameters include total porosity, fractal dimension of pore structure and proportion of dangerous large pores. Dimensionless damage characteristics are obtained by normalizing the porosity parameters of each dimension under each set of cutting parameters. Calculate the interlayer shear strength loss rate based on the measured interlayer shear strength under each set of cutting parameters; A correlation model between the dimensionless damage characteristics and the interlaminar shear strength loss rate was constructed, and the coefficients of the correlation model between the dimensionless damage characteristics and the interlaminar shear strength loss rate were calibrated based on the dimensionless damage characteristics and the interlaminar shear strength loss rate under each set of cutting parameters. A comprehensive structural damage evaluation index calculation model was constructed, and the coefficients of the comprehensive structural damage evaluation index calculation model were back-calculated based on the coefficients of the correlation model between dimensionless damage characteristics and interlaminar shear strength loss rate. A prediction model for interlaminar shear strength was established based on comprehensive structural damage evaluation indicators. After obtaining the multi-dimensional porosity parameters of the CFRP component under test, normalizing them, and inputting them into the comprehensive structural damage evaluation index calculation model, the comprehensive structural damage evaluation index of the CFRP component under test is obtained. The comprehensive structural damage evaluation index is input into the interlaminar shear strength prediction model to obtain the predicted value of the interlaminar shear strength of the CFRP component under test.

2. The method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics according to claim 1, characterized in that, Pores with a diameter greater than a preset dangerous pore diameter threshold are defined as dangerous large pores. The proportion of dangerous large pores is obtained based on pore diameter distribution data, and the proportion of dangerous large pores is the ratio of the volume of the corresponding pore to the total pore volume. When the pore size distribution data is pore volume increment data, the proportion of dangerous large pores is calculated using the following formula: In the formula, The proportion of dangerous large holes, For the first The aperture corresponding to each aperture range For the first The pore volume increment corresponding to each pore size range Preset a dangerous aperture threshold; When the pore size distribution data is the same as the pore volume distribution density data, the proportion of dangerous macropores is calculated using the following formula: In the formula, aperture The corresponding pore volume distribution density, and These represent the lower and upper limits of the aperture testing range, respectively.

3. The method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics according to claim 2, characterized in that, The porosity parameters of each dimension under each set of cutting parameters were normalized using a reference CFRP component sample. The formula for normalizing the total porosity is as follows: In the formula, This represents the normalized porosity factor of the target CFRP component. This represents the total porosity of the target CFRP component. This represents the total porosity of the reference CFRP component sample. This represents the maximum total porosity of the target CFRP component under multiple sets of different cutting parameters; The formula for normalizing the fractal dimension of the pore structure is as follows: In the formula, This represents the normalized pore complexity factor of the target CFRP component. This represents the fractal dimension of the pore structure of the target CFRP component. This represents the fractal dimension of the pore structure of the reference CFRP component sample. This represents the maximum value of the fractal dimension of the pore structure of the target CFRP component under multiple sets of different cutting parameters; The formula for normalizing the proportion of dangerous macropores is as follows: In the formula, This represents the normalized critical hole size factor of the target CFRP component. This indicates the proportion of dangerous large holes in the target CFRP component. This indicates the percentage of hazardous large holes in the reference CFRP component sample. This represents the maximum percentage of critical large holes in the target CFRP component under multiple sets of different cutting parameters; The normalized pore quantity factor, normalized pore complexity factor, and normalized dangerous pore size factor of the target CFRP component under each set of cutting parameters constitute the dimensionless damage characteristics of the target CFRP component under each set of cutting parameters.

4. The method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics according to claim 3, characterized in that, The formula for calculating the interlaminar shear strength loss rate is: In the formula, Indicates the first Interlaminar shear strength loss rate of the target CFRP component under a set of cutting parameters. Indicates the first Measured interlaminar shear strength of the target CFRP component under a set of cutting parameters. This represents the measured interlaminar shear strength of the reference CFRP component sample. Indicates the first Interlaminar shear strength retention rate of the target CFRP component under a set of cutting parameters.

5. The method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics according to claim 4, characterized in that, The correlation model between the dimensionless damage characteristics and the interlaminar shear strength loss rate is as follows: In the formula, Indicates the first Interlaminar shear strength loss rate of the target CFRP component under a set of cutting parameters. , and They represent the first Normalized pore quantity factor, normalized pore complexity factor, and normalized critical hole size factor of the target CFRP component under the set cutting parameters. , and These are the contribution coefficients of the normalized pore quantity factor, normalized pore complexity factor, and normalized dangerous pore size factor to the interlaminar shear strength loss rate, respectively.

6. The method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics according to claim 5, characterized in that, The calculation model for the comprehensive structural damage evaluation index is as follows: In the formula, This represents the comprehensive structural damage evaluation index. , and These represent the normalized pore quantity factor, normalized pore complexity factor, and normalized critical pore size factor of the CFRP component under test, respectively. , and These represent the weighting coefficients of the normalized porosity factor, normalized porosity complexity factor, and normalized critical pore size factor of the CFRP component under test, respectively. ; in, In the formula, This represents the sensitivity coefficient to interlaminar shear strength degradation.

7. The method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics according to claim 6, characterized in that, The interlaminar shear strength prediction model is as follows: In the formula, This represents the predicted interlaminar shear strength of the CFRP member to be tested. The interlaminar shear strength is used as a reference CFRP component sample.

8. The method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics according to claim 7, characterized in that, The method further includes determining the damage level of the CFRP component under test based on the comprehensive structural damage evaluation index calculation model, specifically: when When the damage is less than the first threshold, the CFRP component under test is determined to be slightly damaged. When the damage is greater than or equal to the first threshold and less than the second threshold, the CFRP component under test is determined to have moderate damage. If the damage is greater than or equal to the second threshold, the CFRP component under test is determined to be severely damaged, where the first threshold is less than the second threshold.

9. The method for evaluating cutting damage and predicting interlayer performance of CFRP components based on pore characteristics according to claim 1, characterized in that, The CFRP component under test and the target CFRP component are prepared using the same CFRP material system and manufacturing process.

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