Method for evaluating vibration damage mechanical property of composite material

Abstract

The invention relates to the technical field of reliability evaluation of a composite material structure, and particularly discloses an evaluation method for vibration damage mechanical properties of a composite material. The method comprises the following steps: firstly, clamping a composite material test piece on a special test clamp which can be stable and durable in a vibration environment, and carrying out parameter-controllable vibration excitation on a vibration table to simulate damage; then carrying out mechanical property test on the damaged test piece; and finally, based on the vibration data and the mechanical property data, establishing a vibration parameter-performance degradation correlation model by calculating the performance degradation rate, and performing quantitative evaluation on the vibration damage state of the composite material in combination with microscopic damage analysis. According to the invention, the problem that the vibration test and the performance evaluation process are separated and cannot be quantitatively associated in the prior art is solved, the integrated and quantitative analysis from damage simulation to state evaluation is realized, and the environment temperature influence factor is introduced; accurate data support can be provided for safety design and life prediction of the composite material structure in a specific vibration environment.

Description

Technical Field

[0001] This invention belongs to the technical field of reliability assessment and testing methods for composite material structures, specifically relating to a method for assessing the mechanical properties of composite materials under vibration damage. More specifically, this invention is a systematic assessment method integrating vibration damage simulation, post-damage mechanical property testing, and microscopic damage analysis, used to quantitatively study the influence of vibration environment on the mechanical properties of composite materials and to achieve a scientific assessment of their damage state. Background Technology

[0002] The widespread application of fiber-reinforced composite materials in aerospace and other fields makes the long-term safety and reliability assessment of their structures under complex vibration environments crucial. Although vibration loads are small-amplitude alternating loads, their long-term cumulative effects can induce micro-damage within the composite material, such as microcracks, delamination, and fiber / matrix interface debonding. The initiation and propagation of these micro-damages significantly reduce the material's macroscopic mechanical properties, such as stiffness and strength, ultimately affecting the structure's load-bearing capacity. Therefore, establishing a standardized testing and evaluation method that can effectively correlate "vibration load conditions," "internal damage evolution," and "macroscopic mechanical property degradation" is of significant engineering value for accurately predicting the service life of composite material structures and ensuring their safe operation.

[0003] Currently, research on the testing of composite material properties is largely fragmented. On the one hand, vibration testing, as a routine environmental testing method, is mainly used to assess the vibration durability of structures or to find their natural frequencies. Its output usually indicates whether the specimen passes the test or its frequency response curve, without delving into the changes in the material's mechanical properties after vibration. On the other hand, mature standards exist for testing the static mechanical properties of composite materials (such as tension, compression, and shear) (e.g., ASTM D3039, D3410, D3518), but these tests are typically performed on undamaged, brand-new specimens, or only on specimens damaged by specific loads such as fatigue or impact for residual strength testing. Research directly and systematically linking vibration environment simulation with subsequent composite material mechanical property testing is insufficient. Existing research models are often independent and fragmented, making it impossible to accurately establish a one-to-one causal relationship between "specific vibration history" and "specific performance degradation."

[0004] Comprehensive analysis reveals that existing technologies lack a complete, continuous, and standardized technical process specifically for assessing vibration damage in composite materials. The core problems are: first, the process is fragmented, with vibration damage simulation and mechanical property assessment being two independent steps, potentially interfering with the accuracy of experimental results; second, the assessment dimensions are limited, focusing either solely on vibration response (e.g., acceleration) or only on the final mechanical property values, lacking a systematic approach to correlate data from the vibration process (e.g., vibration time, frequency, acceleration spectrum) with post-damage mechanical property losses and microscopic damage morphology; and third, the results lack quantification, failing to move from "phenomenon description" to "law summary," and unable to effectively answer the crucial engineering question of "how much vibration will cause a significant decrease in material properties."

[0005] Therefore, the technical problem to be solved by this invention is: how to provide a systematic and continuous method for evaluating the mechanical properties of composite materials under vibration damage. This method can first simulate the vibration damage of composite material specimens under controllable parameters in a coherent process, and then transfer it to the mechanical testing stage without damage or with minimal damage. Finally, by combining vibration data, mechanical property data and microscopic damage analysis results, a quantitative assessment of the degree of vibration damage of composite materials can be achieved, thereby filling the gap in the existing technology for this systematic evaluation method.

[0006] It should be noted that the information disclosed in this background section is intended only to enhance the understanding of the overall background of the present invention, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of existing methods for assessing vibration damage in composite materials. Existing technologies typically separate vibration testing from mechanical performance testing, lacking a complete, continuous, and standardized technical process that quantitatively correlates vibration environment simulation, post-damage performance testing, and damage state. This results in the inability to accurately assess the actual impact of vibration history on the mechanical properties of composite materials. Therefore, this invention aims to provide a systematic method for assessing the mechanical properties of composite materials through vibration damage. This method seamlessly integrates vibration damage simulation and mechanical performance testing, and through data correlation analysis, achieves a quantitative and accurate assessment of the vibration damage state of composite materials, thereby providing crucial data support for the reliability design and life prediction of composite structures under vibration environments.

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A method for evaluating the mechanical properties of composite materials under vibration damage is characterized by comprising three core steps: vibration damage simulation, mechanical property testing, and damage assessment.

[0009] First, vibration damage simulation is performed: the composite material test specimen is clamped onto a specialized test fixture capable of maintaining stable clamping in a vibration environment. Then, the fixture is fixed to a vibration table, and parameters including vibration type, frequency, amplitude, acceleration, duration, and ambient temperature are set to excite the test specimen through vibration, causing vibration damage. During this process, vibration response data can be monitored and recorded.

[0010] Next, mechanical property testing is conducted: the mechanical properties of the test specimen after vibration damage are tested. The test items may include tensile, compressive or shear properties in the fiber direction, in-plane perpendicular to the fiber direction and in-plane shear, etc., to obtain mechanical property data after damage.

[0011] Finally, damage assessment is performed: this is the core innovation of this method. This step comprehensively evaluates the damage state of the test specimen based on the aforementioned vibration and mechanical property data. Assessment methods include, but are not limited to: calculating the performance degradation rate and retention rate of the mechanical properties after damage relative to the undamaged reference specimen; establishing a correlation model between vibration parameters, vibration response, and performance degradation rate or retention rate to predict performance evolution; and combining the results of microscopic damage analysis (such as ultra-depth-of-field microscopy, scanning electron microscopy, or ultrasonic testing) to correlate macroscopic performance degradation with microscopic damage morphology, thereby gaining a deeper understanding of the damage mechanism. Ultimately, vibration damage tolerance standards can be established based on the assessment results.

[0012] Preferably, this method can employ multiple specimens for parallel testing to improve efficiency and is applicable to specific layups (such as [0]6,

[90] ). 12 [45 / -45] 4S [45 / 0 / -45 / 90] 2S Composite material test specimens.

[0013] Compared with the prior art, the present invention has the following significant advantages: 1. Achieved systematicness and completeness in the evaluation process: This invention integrates the originally fragmented vibration environment simulation, mechanical performance testing and damage analysis into an organic and continuous technical process, avoiding errors that may be introduced by specimen transfer, and ensuring the consistency of data sources and the certainty of causal relationships.

[0014] 2. Achieved quantitative and predictable damage assessment: By correlating vibration data with mechanical performance data, calculating performance degradation rate, and establishing a predictive model, this invention advances the impact of vibration damage from qualitative description to quantitative assessment, answering the key engineering question of "how much performance degradation occurs under specific vibration conditions," and significantly improving the scientific nature and application value of the assessment.

[0015] 3. It provides multi-scale and multi-dimensional damage analysis methods: By introducing micro-damage analysis, the degradation of macroscopic mechanical properties is directly linked to micro-level damage modes (such as microcracks and delamination), which not only verifies the evaluation results but also deepens the understanding of damage mechanisms, providing direction for material improvement and structural optimization.

[0016] 4. Improved test efficiency and data reliability: By using a special fixture that can hold multiple specimens in parallel, multiple sample data can be obtained from a single vibration test, which not only improves efficiency but also helps to obtain statistically significant patterns and enhances the reliability of the evaluation conclusions.

[0017] In summary, this invention provides a novel and systematic solution for evaluating the mechanical properties of composite materials under vibration damage, filling a gap in existing technologies in this field and having significant theoretical and engineering implications for ensuring the safe operation of composite material structures under vibration environments. Attached Figure Description

[0018] The method for evaluating the vibration damage mechanical properties of composite materials according to the present invention will be further described below with reference to the accompanying drawings. These drawings are intended to clearly illustrate the process, key steps, and core concepts of the method to facilitate understanding.

[0019] Figure 1 This is a flowchart of an embodiment of the method for evaluating the mechanical properties of composite material vibration damage according to the present invention.

[0020] Figure 2 This is a three-dimensional structural diagram of the special test fixture used in the embodiments of the present invention.

[0021] Figure 3 This is a schematic diagram of the test piece clamping steps in this invention.

[0022] Figure 4 This is a flowchart of vibration parameter setting and vibration generation in this invention.

[0023] Figure 5 This is the vibration environment temperature control box in this invention.

[0024] Figure 6 This is a schematic diagram of the mechanical performance testing steps in this invention.

[0025] Figure 7 This is a schematic diagram illustrating the correlation analysis between vibration data and mechanical performance data in the damage assessment step of this invention.

[0026] Figure 8 This is an example diagram of the detailed damage analysis results in the damage assessment step of this invention.

[0027] Figure 9This is a graph showing the change of vibration parameters (such as acceleration spectrum) over time in one embodiment of the present invention.

[0028] Figure 10 This is a schematic diagram of the vibration damage tolerance established after damage assessment in one embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures: 1. Base; 20. Fixing block; 30. Slider; 40. Threaded rod; 50. Locking nut; 60. Composite material test piece; 61. Composite material laminate; 62. Clamping washer; 70. Locking screw; 71. Third locking screw; 73. First locking screw; 80. Vibration table mounting plate; 90. Horizontal slide table; 100. Accelerometer; 110. Vibration generator; 120. Power amplifier; 130. Vibration controller; 140. Vibration environment temperature control box; 150. Testing machine jaws. Detailed Implementation

[0030] The following detailed description, in conjunction with the accompanying drawings, describes a specific implementation of the method for evaluating the vibration damage mechanical properties of composite materials according to the present invention. This description is intended to enable those skilled in the art to fully understand the technical solution of the present invention, the execution details of each step, the data acquisition and processing methods, and to reproduce and apply the present invention accordingly.

[0031] Please see Figure 1 The core of the method for evaluating the mechanical properties of composite materials under vibration damage provided by this invention lies in constructing a systematic, continuous, and quantitative technical process that organically combines vibration damage simulation, post-damage mechanical property testing, and multi-dimensional damage analysis. The method mainly includes three steps: vibration damage simulation, mechanical property testing, and damage assessment. These three steps are performed sequentially, forming a complete causal chain, aiming to accurately reveal the influence of vibration history on the properties of composite materials. Step 1: Vibration Damage Simulation

[0032] The purpose of this step is to simulate the vibration damage that composite material specimens may experience in actual service environments under controlled laboratory conditions. The detailed implementation method is as follows: 1. Preparation of specimens and fixtures

[0033] Preparation of Composite Specimens 60: Based on the research objectives, standardized composite specimens are designed and fabricated. Specimens are typically rectangular strips, whose geometric dimensions must accommodate both the sensitivity of the dynamic testing and the standard requirements of subsequent mechanical testing (e.g., referring to ASTM D3039, approximately 250 mm in length and 25 mm in width). Layup design is crucial; different layup sequences and orientations can be selected according to evaluation needs. In a preferred embodiment, the specimen layup is [0]6,

[90] 12 [45 / -45] 4S [45 / 0 / -45 / 90] 2S These layups allow for the examination of fiber-dominant mechanical properties, matrix-dominant mechanical properties, in-plane shear properties, and quasi-isotropic layup properties. Specimens are cured from carbon fiber / epoxy unidirectional prepreg using an autoclave process to ensure consistent quality. To protect the clamping ends of the specimens, high-strength adhesive can be used to attach clamping gaskets 62 made of aluminum alloy to both ends.

[0034] Preparation of Dedicated Test Fixture: Prepare a dedicated fixture that meets the requirements of vibration testing. The core functions of this fixture are: a) reliable mounting on the vibration table; b) stable and uniform clamping of the composite material test specimen; c) maintaining clamping force without loosening under long-term high-frequency vibration loads. The fixture should be capable of simultaneously clamping multiple specimens (e.g., 2-4) to improve testing efficiency (see [link]). Figure 2 Before use, check that all parts of the fixture (such as base, fixing block, slider, threaded rod, anti-loosening nut and various anti-loosening screws) are intact, that the sliding mechanism is smooth, and clean the contact surface with the test piece. 2. Specimen clamping and vibration table setup

[0035] The prepared composite material test specimen 60 is mounted on a special fixture. Specifically, the clamping pad 62 of the specimen is placed between the fixing block 20 and the slider 30 of the fixture, or between two adjacent sliders 30. Then, the slider 30 is moved by tightening the anti-loosening nut 50 on the threaded rod 40, applying a uniform clamping force to clamp the specimen. To ensure absolute reliability under vibration, the slider 30 is further tightened using a first anti-loosening screw 73. If the fixture supports parallel testing of multiple specimens, all specimens are clamped side-by-side in the same manner.

[0036] Securely install the clamped specimen assembly onto the vibration table mounting plate 80 using the third anti-loosening screw 71 (see...). Figure 3 Ensure the connection is secure and that the lower plane of the clamp base is in full contact with the mounting surface of the vibration table mounting plate 80. 3. Vibration parameter setting and damage simulation execution

[0037] Vibration parameter setting: Vibration test parameters are set through the vibration control system. These parameters are crucial for simulating the real environment and must be selected based on the typical vibration environment of the research object (such as a specific part of an aircraft). Parameters include: Vibration type: You can choose sinusoidal fixed-frequency vibration, sinusoidal swept-frequency vibration, random vibration, etc. Random vibration can better simulate actual broadband excitation.

[0038] Vibration frequency: For sweep frequency vibration, a frequency range needs to be set (e.g., 10-2000Hz); for fixed frequency vibration, a fixed frequency needs to be set (e.g., 30Hz).

[0039] Vibration amplitude: Set the amplitude or peak value of the vibration, which is determined by the distance of the horizontal slide 90 pushed and pulled by the vibration generator 110. For example, the peak value of the vibration is 10mm.

[0040] Vibration acceleration: The maximum value of vibration acceleration can be limited by setting the peak acceleration, such as 12.6g. Setting the vibration magnitude, such as a sinusoidal constant-frequency vibration with a peak acceleration of 12.6g, results in a root mean square (Grms) acceleration of 8.9g. This is a key parameter for controlling vibration energy input.

[0041] Vibration duration: The vibration duration can be set according to research needs, such as 24 hours, 96 hours, 168 hours, etc., and the number of vibration cycles is a certain number (for example, at a frequency of 30Hz, lasting for 24 hours, the number of cycles is approximately 2,592,000). The duration directly affects the degree of damage accumulation.

[0042] Vibration ambient temperature: The test temperature can be adjusted in the vibration ambient temperature control box 140 (see...). Figure 5 ), simulating specific working conditions (such as -60 to 150 °C).

[0043] Vibration and data monitoring: Start the vibration table and related equipment, set the vibration parameters in the vibration controller 130, and input the vibration parameter signal to the power amplifier 120 for modulation. The modulated signal is then input to the vibration generator 110 to excite the corresponding modulated vibration. The vibration generator pushes and pulls the horizontal slide 90, which is fixed together with the vibration table mounting plate 80, transmitting the corresponding vibration to the special fixture and composite material test piece 60. The acceleration sensor 100 is installed on the horizontal slide 90, or the test piece 60, or both, to monitor and provide feedback on the vibration acceleration (see...). Figure 4 The recorded vibration data (such as acceleration time history and power spectral density PSD) will serve as an important input for subsequent damage assessment. Step 2: Mechanical property testing

[0044] After the vibration damage simulation is completed, the fixture is removed from the vibration table mounting plate 80, and then the composite material test specimen 60 is taken out. Next, the clamping pad 62 of the composite material test specimen 60 is clamped by the jaws of the testing machine. Finally, the jaws of the testing machine move up or down to perform mechanical testing on the composite material test specimen 60 (see...). Figure 6 Note: Carefully transfer the specimen into the fixture of the standard mechanical testing machine to avoid additional damage or errors that may be caused by re-clamping.

[0045] 1. Test Item Selection: Based on the research objectives, select one or more mechanical property testing methods. Common methods include: Fiber-direction mechanical property test: mainly evaluates fiber-dominant properties, such as tensile or compressive strength and modulus in the 0° direction.

[0046] In-plane mechanical property tests perpendicular to the fiber direction: mainly evaluate the matrix-dominated properties and fiber / matrix interface properties, such as tensile or compressive strength and modulus in the 90° direction.

[0047] In-plane shear mechanical property testing: This assesses the shear properties of a material, such as by [45 / -45]. 4S In-plane shear properties of laminates are obtained through tensile testing.

[0048] Quasi-isotropic layup performance test: Passed [45 / 0 / -45 / 90] 2S Tensile or compression tests are conducted on laminates to obtain the corresponding stress-strain curves.

[0049] The testing methods should comply with the relevant ASTM or ISO standards.

[0050] 2. Data Acquisition: Conduct mechanical tests until the specimen fails. Record complete load-displacement and stress-strain curves, and calculate key mechanical performance parameters, such as ultimate strength σ. ult Elastic modulus E, failure strain ε f For each performance parameter, data from at least 3-5 valid specimens should be obtained to calculate the mean and standard deviation, ensuring the statistical reliability of the data.

[0051] Step 3: Damage Assessment This step is the core of the method's innovation, aiming to transform the data obtained in the first two steps into a deep understanding and quantitative assessment of the damage state.

[0052] Performance degradation rate calculation (basic quantitative assessment): Prepare a set of reference specimens (undamaged by vibration) that are identical to the vibration test specimen, and conduct mechanical property tests under the same conditions. Obtain their average mechanical property value as the reference value (P). baseline ).

[0053] For each set of vibration conditions (i.e., a specific combination of vibration parameters), calculate the average mechanical property value (P) of the specimen after damage. damaged ).

[0054] Calculate the mechanical property degradation rate (η): η = (P baseline - P damaged ) / P baseline * 100%. This value visually reflects the percentage of performance loss caused by vibration damage.

[0055] Calculate the retention rate of mechanical properties (λ): λ = 1 - η = P damaged / P baseline * 100%. This value directly reflects the remaining performance after vibration damage.

[0056] 2. Correlation Model Construction and Prediction (Advanced Quantitative Assessment): like Figure 7 As shown, different vibration parameters (such as vibration time t, vibration cycle number N, acceleration level A, temperature T) or vibration response data (such as cumulative energy) are used as independent variables (X), and the calculated performance degradation rate η or performance retention rate λ is used as dependent variables (Y).

[0057] A data fitting method (such as least squares) is used to establish a correlation model between X and η. This model can be a simple linear relationship η = k * X, or a more complex nonlinear function η = f(X). For example, a curve relating vibration time to stiffness degradation rate can be established.

[0058] Using this model, it is possible to predict the performance of composite materials under specific vibration histories (such as longer vibration times t). predict The degree of performance degradation η under ) predict This provides a basis for predicting the remaining life of the structure.

[0059] 3. Microscopic damage analysis (mechanism verification and in-depth analysis): Samples containing the damaged area were cut from the damaged specimen.

[0060] Using a super depth-of-field 3D microscope, one can observe the side or fracture surface of a sample to obtain a large-scale damage morphology, such as the delamination area and crack propagation path.

[0061] Scanning electron microscopy (SEM) was used to observe typical damaged areas (such as fracture surfaces) at high magnification, and to analyze microscopic features such as fiber fracture modes (brittle fracture / pull-out), matrix cracking, and fiber / matrix interface debonding. Figure 8 This helps to directly link macroscopic performance degradation with microscopic damage mechanisms.

[0062] Alternatively, non-destructive testing methods such as ultrasonic C-scan can be used to image and quantitatively assess internal damage (such as delamination) in specimens after vibration and before mechanical testing.

[0063] 4. Comprehensive assessment and establishment of damage tolerance: Based on all the above data (performance degradation rate, correlation model, and microscopic damage morphology), a comprehensive evaluation of the damage tolerance of the composite material under this vibration condition is made.

[0064] Based on an engineering-acceptable safety margin, vibration damage tolerance can be defined. For example, the vibration condition corresponding to a strength degradation not exceeding a certain percentage (e.g., 20%) can be defined as the safety threshold for the material (see [link to relevant documentation]). Figure 10 This threshold is crucial for structural designers.

[0065] Example 1: Evaluation of damage to a certain type of carbon fiber / epoxy resin laminate (layout [0]6) under random vibration.

[0066] 1. Vibration Simulation: Set a sinusoidal fixed-frequency vibration spectrum (frequency 30Hz, maximum acceleration 12.6g (Grms=8.9g), see... Figure 9 The vibration environment temperature was set at 100℃, and the durations were 24h, 96h, 168h, 240h, and 312h. Three specimens were tested in parallel for each group. The vibration response was recorded.

[0067] 2. Mechanical Testing: After vibration, a longitudinal tensile test was conducted. The measured reference strength was P. b = 1500 MPa. After 312 hours of vibration, the average intensity P d = 1183.5 MPa.

[0068] 3. Damage assessment: Strength degradation rate: η strength = (1500-1183.5) / 1500 * 100% = 21.1%.

[0069] Strength retention rate: λ strength =1-21.1%=78.9%.

[0070] Model establishment: Let the vibration time t be X, λ strength For Y, a non-linear relationship was found; see [link / reference]. Figure 10 (t unit: 24 hours).

[0071] Detailed analysis: SEM showed that after 168 hours of vibration, the specimen fracture surface showed obvious interface debonding and matrix microcracks, and these damages were more severe after 312 hours.

[0072] Damage tolerance: If the specified strength degradation rate tolerance is 20% (i.e., the retention rate tolerance is 80%), then according to the model, the maximum allowable vibration time under these vibration parameters and environment is approximately 300 hours.

[0073] As can be seen from the above detailed embodiments, the method of the present invention has the following significant effects: 1. Systematic: It integrates discrete experimental steps into a seamless process with a complete data chain and clear causal relationships.

[0074] 2. Quantification: Through performance degradation rate and prediction model, the degree of damage is accurately quantified, surpassing traditional qualitative or phenomenon description.

[0075] 3. Profound Mechanism: Combining macroscopic performance with microscopic morphology, it not only tells us "how much performance has decreased", but also helps us understand "why the performance has decreased", thus guiding material optimization.

[0076] 4. High efficiency and reliability: Parallel experimental design improves the efficiency and quality of data acquisition, and correlation models provide direct and reliable prediction tools for engineering applications.

[0077] In summary, this specific embodiment fully discloses each step and detail of the evaluation method of the present invention, and fully demonstrates the method's advancement, practicality, and reproducibility.

Claims

1. A method for evaluating the mechanical properties of composite materials under vibration damage, characterized in that, Includes the following steps: Step S100, vibration damage simulation: The composite material test piece (60) is clamped on a special test fixture and the fixture is fixed to the vibration table; the vibration parameters are set and the composite material test piece is subjected to vibration excitation to cause vibration damage to the test piece; wherein, the special test fixture can realize the stable clamping of the test piece and maintain the clamping reliability in the vibration environment; Step S200, Mechanical property test: The test piece after step S100 is subjected to mechanical property test to obtain its mechanical property data after damage. Step S300, Damage assessment: Based on the vibration response data of step S100 and the mechanical property data of step S200, assess the vibration damage state of the composite material test specimen (60).

2. The method according to claim 1, characterized in that, The following steps are included prior to the vibration damage simulation step: Specimen and fixture preparation steps: Prepare composite material specimens with a predetermined layup structure; and prepare the special test fixtures.

3. The method according to claim 1, characterized in that, The vibration parameters include one or more of the following: vibration type, vibration frequency, vibration amplitude, vibration acceleration, vibration duration, and vibration ambient temperature.

4. The method according to claim 1 or 3, characterized in that, In step S100, the output response of the vibration table and / or the vibration response of the test piece are monitored and recorded as the vibration data.

5. The method according to claim 1, characterized in that, The mechanical property tests include at least one of the following: tensile or compressive property tests along the fiber direction, tensile or compressive property tests in-plane perpendicular to the fiber direction, in-plane shear property tests, and quasi-isotropic layup property tests.

6. The method according to claim 1, characterized in that, Step S300 includes: The mechanical property data after damage are compared with the baseline mechanical property data of the reference specimen that has not experienced vibration damage, and the mechanical property degradation rate and retention rate are calculated.

7. The method according to claim 6, characterized in that, Step S300 further includes: Establish a correlation model between the vibration parameters, the vibration data, and the mechanical property degradation rate or retention rate; Based on the aforementioned correlation model, the performance degradation of composite materials under specific vibration environments is predicted.

8. The method according to claim 1, characterized in that, Step S300 further includes a micro-damage analysis sub-step: The test specimen after vibration damage was subjected to detailed observation to obtain information on its internal damage morphology. Based on the aforementioned mechanical performance data, the damage modes and damage extent corresponding to different vibration conditions are analyzed; The microscopic damage analysis employs at least one of the following methods: ultra-depth-of-field three-dimensional microscopy analysis, scanning electron microscopy analysis, or ultrasonic non-destructive testing analysis.

9. The method according to claim 1, characterized in that, The method further includes: Based on the results of the damage assessment steps, a vibration damage tolerance is established, which is used to define the acceptable threshold for the degradation of the mechanical properties of the composite material under vibration.

10. The method according to claim 1, characterized in that, In the vibration damage simulation step, multiple identical composite material test specimens (60) are simultaneously subjected to vibration damage simulation on the dedicated test fixture to obtain statistically significant evaluation data.

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