A method and system for characterizing the vibration attenuation properties of a plastic material

Abstract

The application discloses a method and system for characterizing vibration attenuation characteristics of plastic materials, and belongs to the field of material detection. The method comprises the following steps: preparing a random gray distribution image on a sample by using black and white spraying materials to obtain a first sample; applying a first displacement to the first sample by a vibration attenuation testing device and then releasing the first sample, while recording the amplitude change of the first sample in the whole process from the first displacement to complete stillness to obtain a vibration attenuation data set describing the amplitude change of the first sample with time, and an amplitude change data describing the displacement change of a preset monitoring point in the first sample with time, and constructing a vibration amplitude attenuation curve of the first sample; and calculating a damping loss factor of the first sample according to the vibration amplitude attenuation curve to characterize the vibration attenuation characteristics of the first sample. The amplitude attenuation of the material is recorded by a camera and a laser instrument, and test data can be quickly obtained and the test cost is reduced.

Description

Technical Field

[0001] This application belongs to the field of materials testing, specifically relating to a method and system for characterizing the vibration attenuation characteristics of plastic materials. Background Technology

[0002] Mechanical vibration can lead to instability in the structural stress state of materials, causing mechanical fatigue. Prolonged exposure to vibration can result in fatigue failure of structural materials, ultimately leading to material failure. Furthermore, mechanical vibration generates noise and shocks, causing discomfort in people's living and working environments. Therefore, when designing high-speed mechanical products, materials often need to possess high vibration damping properties to overcome the reduction in product lifespan and comfort caused by vibration.

[0003] The vibration damping characteristics of a material reflect its ability to dissipate external energy. During vibration, mechanical vibration energy loss occurs due to internal factors such as friction between molecules / grains, and is generally characterized using damping. Currently, dynamic mechanical analyzers (DMA) are commonly used to test the loss factor (tanδ) of materials to study the vibration damping performance of plastic materials. It has been found that the loss factor can effectively detect differences in vibration damping performance between different substrates. However, subtle differences between materials with different formulation modifications on the same substrate are difficult to characterize intuitively. Furthermore, characterizing material vibration characteristics using the DMA method requires specialized instruments, resulting in high testing costs and long testing cycles. Summary of the Invention

[0004] This application proposes a method and system for characterizing the vibration attenuation characteristics of plastic materials. By recording the amplitude attenuation of the material using a camera and laser instruments, the vibration attenuation characteristics of different materials can be obtained quickly and the experimental cost can be reduced.

[0005] The first aspect of this application provides a method for characterizing the vibration damping properties of a plastic material, the method comprising:

[0006] Random grayscale distribution images were prepared on the sample using black and white spray materials to obtain the first sample.

[0007] The vibration attenuation test device applies a first displacement to the first sample and then releases it. Simultaneously, it records the amplitude change of the first sample from the release of the first displacement to complete rest. This yields a vibration attenuation dataset describing the amplitude change of the first sample over time, and amplitude change data describing the displacement change of a preset monitoring point in the first sample over time.

[0008] Based on the vibration attenuation dataset and the amplitude change data, a vibration amplitude attenuation curve for the first specimen is constructed.

[0009] Based on the vibration amplitude attenuation curve, the damping loss factor of the first sample is calculated to characterize the vibration attenuation characteristics of the first sample.

[0010] The above scheme first prepares a high-contrast random grayscale distribution image using black and white spraying materials, which can more clearly show the subtle differences in vibration in subsequent experiments. Then, one end of the sample is fixed to reduce the interference of external vibration on the test results, and displacement is applied to the other end of the sample to simulate the stress state of the first sample. Then, the displacement is released to make the first sample vibrate, and the entire process from vibration to rest is recorded by image acquisition and a laser rangefinder for the first sample and a monitoring point on the first sample, respectively. Test data can be obtained without contacting the sample, which improves the accuracy of the data. Then, the damping loss factor is obtained by collecting vibration attenuation data and amplitude change data to quantify the amplitude attenuation characteristics of the first sample. The test of the vibration attenuation characteristics of the material can be completed with simple operation, which is more efficient than traditional test methods and ensures the accuracy of test results.

[0011] In one possible implementation of the first aspect, a random grayscale distribution image is prepared on the sample using black and white spray materials to obtain the first sample, specifically:

[0012] The random grayscale distribution image is determined according to the testing requirements;

[0013] When the random grayscale distribution image is a black background with random white speckles, first use black spray to spray a layer of paint film on the sample, and then use white spray to randomly spray on the paint film to obtain the first sample;

[0014] When the random grayscale distribution image is a white background with random black speckles, first use white spray to spray a layer of paint film on the sample, and then use black spray to randomly spray on the paint film to obtain the first sample.

[0015] The above method uses black and white sprays with high contrast to create random grayscale distribution images, which allows for more intuitive observation of material vibration changes during subsequent vibration tests and provides accurate test data.

[0016] In one possible implementation of the first aspect, a first displacement is applied to the first specimen using a vibration attenuation testing device and then released. Simultaneously, the amplitude change of the first specimen during the entire process from the release of the first displacement to complete rest is recorded. This yields a vibration attenuation dataset describing the amplitude change of the first specimen over time, and amplitude change data describing the displacement change of a preset monitoring point in the first specimen over time. Specifically:

[0017] The first specimen is fixed at one end using a vibration damping test device, a first displacement is applied to the other end, and then it is released.

[0018] The vibration attenuation test device is used to acquire images of the first specimen from the release of the first displacement to complete rest, and the amplitude of the first specimen at different time points during the process is recorded to obtain the vibration attenuation dataset.

[0019] The amplitude change data is obtained by recording the displacement change of a preset monitoring point in the first sample relative to the initial position of the monitoring point during the entire time period from the release of the first displacement to complete rest; wherein the monitoring point is selected from the random grayscale distribution image of the first sample; the initial position of the monitoring point is the position of the monitoring point before the release of the first displacement of the first sample.

[0020] The above method first fixes one end of the first specimen to ensure that it does not shift during subsequent vibration and thus affect the test results. Then, a certain displacement is applied to the other end and then released to simulate the stress process of the material and record the impact of the vibration generated by the stress on the material structure, obtaining vibration attenuation data and amplitude change data respectively. Because both types of test data are acquired non-contactly, the interference of contact on the test results is reduced, and test results can be obtained quickly and accurately.

[0021] In one possible implementation of the first aspect, the amplitude change data is obtained by recording the displacement change of a preset monitoring point in the first sample relative to the initial position of the monitoring point, specifically as follows:

[0022] The side containing the random grayscale distribution image of the first sample is placed in the center of the camera of the vibration attenuation test device. Then, the laser beam of the vibration attenuation test device is focused on the monitoring point, and the displacement change of the monitoring point is recorded throughout the process to obtain the amplitude change data.

[0023] In one possible implementation of the first aspect, the vibration amplitude attenuation curve of the first specimen is specifically as follows:

[0024]

[0025] In the formula, x is the mass displacement of the first sample, A is the complex amplitude of the mass displacement, ξ is the damping ratio, Ω is the preset undamped natural frequency of the single-degree-of-freedom system, t is the amplitude decay time, and α is the initial phase.

[0026] In one possible implementation of the first aspect, the damping loss factor is specifically:

[0027]

[0028] In the formula, γ is the damping loss factor, and A1 and A3 are the amplitudes of any two adjacent positive or negative peaks.

[0029] The second aspect of this application provides a characterization system for the vibration attenuation characteristics of plastic materials, the system comprising: a sample preparation module, an amplitude data recording module, an attenuation curve construction module, and a damping loss factor calculation module;

[0030] The sample preparation module is used to prepare a random grayscale distribution image on the sample using black and white spray materials to obtain the first sample.

[0031] The amplitude data recording module is used to apply a first displacement to the first sample through the vibration attenuation test device and then release it, while recording the amplitude change of the first sample from the release of the first displacement to complete rest. This results in a vibration attenuation dataset describing the change of the amplitude of the first sample over time, and amplitude change data describing the change of the displacement of the preset monitoring point in the first sample over time.

[0032] The attenuation curve construction module is used to construct the vibration amplitude attenuation curve of the first sample based on the vibration attenuation dataset and the amplitude change data.

[0033] The damping loss factor calculation module is used to calculate the damping loss factor of the first sample based on the vibration amplitude attenuation curve, so as to characterize the vibration attenuation characteristics of the first sample.

[0034] In one possible implementation of the second aspect, a vibration attenuation testing device is also included;

[0035] The vibration attenuation testing device includes a device calibration module, a displacement application module, and an amplitude measurement module.

[0036] The device calibration module includes a metal base containing a shock-absorbing device for fixing the displacement application module and the amplitude measurement module;

[0037] The displacement application module includes a cylinder, a tightening device, a blocking device, a clamp, and a clamping plate, used to fix the first sample by the clamp and clamping plate, and to adjust the rotation angle of the blocking device by controlling the cylinder and the tightening device to apply or release the first displacement to the first sample.

[0038] The amplitude measurement module includes a laser rangefinder and a camera, used to record the entire process of the first sample from the release of the first displacement to complete rest.

[0039] In one possible implementation of the second aspect, the first sample is fixed by a clamp and a clamping plate, and the rotation angle of the blocking device is adjusted by controlling the cylinder and the tightening device to apply or release a first displacement to the first sample, specifically:

[0040] One end of the first sample is fixed using a clamp and a clamping plate, and the other end of the first sample is placed on the blocking device.

[0041] The cylinder is driven by a rotating tightening device, and the blocking device is rotated under the action of the cylinder to apply displacement to the first sample.

[0042] When the blocking device rotates to a preset test angle, the blocking device is controlled to release a displacement toward the first sample, so that the first sample begins to vibrate; wherein, the first displacement is determined by the test angle.

[0043] In one possible implementation of the second aspect, the entire process of the first specimen from the release of the first displacement to complete rest is recorded, specifically as follows:

[0044] The camera captures images of the first sample from the release of the first displacement to complete rest, thus obtaining a vibration attenuation dataset.

[0045] The laser beam of the laser rangefinder is focused on a preset monitoring point in the first sample, and the amplitude change data is obtained by recording the monitoring point through the laser beam. Attached Figure Description

[0046] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This is a schematic flowchart illustrating a method for characterizing the vibration attenuation characteristics of a plastic material according to a certain embodiment of this application.

[0048] Figure 2 This is a sample rebound diagram illustrating a method for characterizing the vibration damping characteristics of a plastic material according to a certain embodiment of this application.

[0049] Figure 3 This is a random grayscale distribution image of a method for characterizing the vibration attenuation characteristics of a plastic material according to a certain embodiment of this application;

[0050] Figure 4 This is a laser displacement sensor measurement diagram of a method for characterizing the vibration attenuation characteristics of a plastic material according to a certain embodiment of this application;

[0051] Figure 5 This is a vibration attenuation curve diagram of a method for characterizing the vibration attenuation characteristics of a plastic material according to a certain embodiment of this application;

[0052] Figure 6This is a panoramic view of the testing apparatus for a method of characterizing the vibration attenuation characteristics of a plastic material according to a certain embodiment of this application;

[0053] Figure 7 This is a front view of a test apparatus for characterizing the vibration damping characteristics of a plastic material according to a certain embodiment of this application;

[0054] Figure 8 This is a side view of a test apparatus for a method of characterizing the vibration damping characteristics of a plastic material according to a certain embodiment of this application;

[0055] Figure 9 This is a structural diagram of a characterization system for vibration attenuation characteristics of plastic materials provided in a certain embodiment of this application. Detailed Implementation

[0056] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0057] It should be understood that the step numbers used in the text are for ease of description only and are not intended to limit the order in which the steps are performed.

[0058] First Embodiment

[0059] Mechanical vibrations caused by external factors can lead to uneven stress distribution in the material structure, potentially causing damage and reducing the lifespan and performance of products made from it. Therefore, in manufacturing high-speed mechanical products, materials often need to possess high vibration damping characteristics to overcome the impact of vibration. Vibration damping characteristics reflect a material's ability to dissipate external energy, and damping loss factors are commonly used to characterize these characteristics. While damping loss factors effectively reveal the differences in vibration damping characteristics between different materials, subtle differences between materials with different formulation modifications based on the same matrix are still difficult to characterize intuitively. Therefore, the main research direction of this application is how to quickly obtain the damping loss factors of different materials at a lower experimental cost to more intuitively characterize vibration damping characteristics.

[0060] like Figure 1 As shown, Figure 1 This application provides a schematic flowchart of a method for characterizing the vibration damping characteristics of a plastic material according to a certain embodiment. The method for characterizing the vibration damping characteristics of the plastic material in this embodiment includes steps S1 to S4, which are detailed below:

[0061] Step S1: Use black and white spray materials to prepare a random grayscale distribution image on the sample to obtain the first sample.

[0062] The specimens in the embodiments of this application are elongated and are generally prepared by injection molding and compression molding. In other embodiments, elongated specimens can also be obtained by stretching the specimens.

[0063] To prepare a high-contrast random grayscale distribution image, black and white spray paints were used to uniformly coat the sides of the sample. Specifically, the sample surface was first cleaned, then a black matte spray paint was uniformly applied to the sides, forming a uniform black paint film. Next, white matte paint was randomly sprayed onto the black paint film, creating a high-contrast random grayscale distribution image with white random spots on a black background on the sides. The sides were then allowed to air dry naturally, resulting in a sample with the random grayscale distribution image, designated as the first sample.

[0064] In some embodiments, a random grayscale distribution image with white background and black random speckles can also be prepared on the side of the sample. The order of spraying is changed to first spraying a layer of paint film on the sample with white spray material, and then randomly spraying black spray material on the paint film.

[0065] The prepared random grayscale distribution image can make the distinction between the sample boundary and the environmental background clearer during image capture; moreover, the subsequent black and white speckle images can be used to calculate the vibration attenuation amplitude based on DIC (digital image correlation technology) (data processing software is used for data processing), thereby improving the data processing efficiency of the embodiments of this application.

[0066] Optionally, in other embodiments, other high-contrast spray materials can be used to prepare random grayscale distribution images, as long as the speckle and the bottom surface can be clearly distinguished, which helps to observe the vibration attenuation of the first sample through the acquired images.

[0067] Step S2: Apply a first displacement to the first sample using a vibration attenuation testing device and then release it, and record the entire process from the release of the first displacement to complete stillness of the first sample to obtain vibration attenuation data set and amplitude change data.

[0068] In this embodiment of the application, a vibration attenuation testing device is used to fix one end of the first sample to prevent the first sample from loosening during the test and causing the test to fail. Then, a certain displacement is applied to the other end of the first sample through the vibration attenuation testing device.

[0069] Specifically, the vibration attenuation testing device includes a cylinder, a tightening device, a blocking device, a clamp, and clamping plates. The clamp and clamping plates hold one end of the first sample. By extending and retracting the cylinder and rotating the tightening device, the blocking device is fine-tuned and locked. Adjusting the blocking device to a certain angle applies displacement to the first sample. Adjusting the cylinder and tightening device ensures accurate setting of test conditions, improving the precision of the test results.

[0070] The fixture is customized according to the shape, size, and testing requirements of the first sample. It works with clamping plates to achieve quick and stable clamping, ensuring the stable position of the first sample during testing. The blocking device is designed as a rotatable structure, capable of rotating 90° under the drive of a cylinder, thereby releasing the sample and causing it to rebound and vibrate. The surface of the blocking device is also covered with a low-friction material, which reduces interference with the sample's rebound process and further improves the accuracy of the test results.

[0071] Optionally, in this embodiment of the application, a displacement of 12.5 mm is applied to the first sample, which is a plastic product.

[0072] After the blocking device rotates to the preset test angle, it is released to allow the first sample to rebound and vibrate. Simultaneously with the release of displacement of the first sample, the high-speed camera of the vibration attenuation testing device captures images of the first sample from the release of displacement to complete rest, recording the entire process of amplitude attenuation over time during release. By recording the amplitude of the first sample at different time points during the entire process from release of displacement to complete rest using the acquired images, a vibration attenuation dataset is obtained.

[0073] Specifically, when clamping the first sample, the parameters of the high-speed camera are first adjusted, the first sample is placed in the center of the camera lens, and the camera is started to record the entire process of the first sample from rebounding to complete stillness while releasing the blocking device.

[0074] In addition, to compare the vibration damping characteristics of multiple materials, the same displacement is usually applied to the samples corresponding to the multiple materials. By comparing the time it takes for these samples to bounce back to complete rest, the vibration damping characteristics of different materials can be qualitatively compared. The shorter the time, the better the vibration damping characteristics of the material.

[0075] Simultaneously with the release of displacement of the first specimen, the displacement change of a preset monitoring point on the first specimen relative to its initial position is recorded using a laser rangefinder of the vibration attenuation testing device throughout the entire time period from the release of the first displacement to complete rest, thus obtaining the amplitude change data. The monitoring point is selected from a random grayscale distribution image of the first specimen, and its initial position is the position of the monitoring point before the release of displacement.

[0076] Specifically, after the laser rangefinder is precisely calibrated and started, the laser beam of the laser rangefinder is focused on a preset monitoring point. As the first sample rebounds, the displacement change of the monitoring point relative to its initial position is continuously recorded throughout the entire process of the first sample rebounding to complete rest, thus obtaining the amplitude change data of the monitoring point throughout the entire process of the first sample rebounding.

[0077] The laser rangefinder is a high-precision non-contact measuring tool used to record the displacement changes of the first sample during its rebound process in real time, resulting in highly accurate and fast-responding test data. Furthermore, compared to existing contact-based data acquisition devices, the laser rangefinder's non-contact measurement reduces the impact on test results.

[0078] Figure 2 The document provides a sample rebound illustration of an embodiment of this application. From left to right, it shows the entire process of the first sample being displaced by the blocking device and rebounding during the release of the displacement. The first and second images show how a certain displacement is applied to the first sample. In the third image, the displacement is released to the first sample. The first sample begins to rebound in the subsequent fourth and fifth images. At this time, the rebound process of the sample is recorded by a laser rangefinder and a camera.

[0079] Figure 3 The images show random grayscale distributions of three different material samples: black background with white spots on the side of PPS (polyphenylene sulfide), PBT (polybutylene terephthalate), and TLCP (thermotropic liquid crystal molecules).

[0080] Figure 4 A schematic diagram of the laser displacement sensor and selected monitoring points is provided. In the diagram, green represents the laser displacement sensor, light blue bars represent the sample, and the sample side has a random grayscale distribution image. The monitoring points are located on the upper surface of the sample and can be selected by the distance from the sample clamping end. The camera is used to capture high-resolution images of the random grayscale distribution image during the rebound process.

[0081] Step S3: Based on the vibration attenuation dataset and amplitude change data, construct the vibration amplitude attenuation curve of the first sample.

[0082] In this embodiment of the application, the obtained vibration attenuation dataset and amplitude change data are compared to determine the time from the release of the load to complete cessation of the first specimen and to construct the vibration amplitude attenuation curve of the first specimen.

[0083] The vibration amplitude attenuation curve of the first sample is as follows:

[0084]

[0085] In the formula, x is the mass displacement of the first sample, A is the complex amplitude of the mass displacement, ξ is the damping ratio, Ω is the preset undamped natural frequency of the single-degree-of-freedom system, t is the amplitude decay time, and α is the initial phase.

[0086] Step S4: Calculate the damping loss factor of the first sample based on the vibration amplitude attenuation curve to characterize the vibration attenuation characteristics of the first sample.

[0087] In this embodiment of the application, the vibration attenuation performance of the material is quantitatively determined based on the vibration amplitude attenuation curve and a preset damping loss factor calculation formula.

[0088] The damping loss factor is specifically:

[0089]

[0090] In the formula, γ is the damping loss factor.

[0091] Among them, for It is actually the natural logarithm of the ratio of the amplitudes of any two adjacent positive or negative peaks, and its specific expression is:

[0092]

[0093] In the formula, T d For the vibration decay period, when ξ is relatively small, i.e., 1-ξ 2 When ≈1, the damping loss factor is 2ξ, at which point we have

[0094] To better compare the vibration damping performance of different materials Figure 4 Vibration decay curves for two types of specimens are provided, with the purple line representing specimen 4#-2 and the cyan line representing specimen 2#-1. These two specimens are TLCP specimens with different formulations prepared by injection molding, and the specimen dimensions are ISO 527 1A type tensile specimens. During the time period shown in the figure, the vibration decay change of the cyan line is significantly greater than that of the purple line, indicating that the vibration decay performance of specimen 4#-2 is superior to that of specimen 2#-1.

[0095] This application also provides a vibration attenuation testing device for measuring the vibration attenuation performance of materials. The vibration attenuation testing device mainly includes a device calibration module, a displacement application module, and an amplitude measurement module. The device calibration module includes a metal base containing a shock-absorbing device, made of a high-strength, high-stability metal material, used to fix the displacement application module and the amplitude measurement module, ensuring stability and accuracy during the testing process. Furthermore, the metal base has an embedded shock-absorbing device to reduce the interference of external vibrations on the test results.

[0096] The displacement application module includes a cylinder, a tightening device, a blocking device, a clamp, and a clamping plate. It is used to fix the first sample using the clamp and clamping plate. The rotation angle of the blocking device is adjusted by controlling the cylinder and tightening device to apply or release a first displacement to the first sample, ensuring accurate setting of the test conditions. The clamp is meticulously designed according to the shape, size, and test requirements of the sample, perfectly conforming to the sample's contour for precise positioning. Simultaneously, the clamping plate is located inside the clamp, and through a fine adjustment and locking mechanism, it easily and securely clamps the sample within the clamp, preventing it from shifting or falling off during the test.

[0097] Furthermore, through precise adjustment of the tightening device, the cylinder is fixed in a position optimal for the testing requirements. At this point, a blocking device is cleverly positioned at one end of the sample, physically obstructing it to form a certain tilt angle. This design not only simulates the initial shape of the sample under stress but also prepares it for subsequent vibration rebound tests.

[0098] The amplitude measurement module includes a laser rangefinder and a camera, used to record the entire process of the first sample from the release of the first displacement to complete rest.

[0099] This application provides embodiments that Figure 5 , 6 Sections 7 and 8 respectively show the panoramic view, front view, and side view of the vibration attenuation testing device. For example... Figure 5 As shown, 1 is a metal base, 2 is a laser rangefinder, 4 is a cylinder, 5 is a blocking device, 6 is a tightening device, 7 is a sample, 8 is a clamping plate, and 9 is a fixture.

[0100] Implementing the embodiments of this application has the following beneficial effects:

[0101] This embodiment first prepares a high-contrast random grayscale distribution image using black and white spraying materials, which can more clearly show the subtle differences in vibration in subsequent experiments. Then, one end of the sample is fixed to reduce the interference of external vibration on the test results, and displacement is applied to the other end of the sample to simulate the stress state of the first sample. Then, the displacement is released to make the first sample vibrate, and the entire process of the first sample from vibration to rest is recorded by image acquisition and laser ranging. Test data can be obtained without contacting the sample, which improves the accuracy of the data. Then, the damping loss factor is obtained by collecting vibration attenuation data and amplitude change data to quantify the amplitude attenuation characteristics of the first sample. The test of the vibration attenuation characteristics of the material can be completed with simple operation, which is more efficient than traditional test methods and also ensures the accuracy of the test results.

[0102] Second Embodiment

[0103] Furthermore, in order to implement the characterization system for the vibration damping characteristics of plastic materials corresponding to the above method embodiments, and to achieve the corresponding functions and technical effects, Figure 8 A structural diagram of a system for characterizing the vibration damping characteristics of plastic materials is provided. For ease of explanation, only the parts relevant to this embodiment are shown. The system for characterizing the vibration damping characteristics of plastic materials provided in this application embodiment includes:

[0104] The sample preparation module 201 is used to prepare a random grayscale distribution image on the sample using black and white spray materials to obtain the first sample.

[0105] To prepare a high-contrast random grayscale distribution image, black and white spray paints were used to uniformly coat the sides of the sample. Specifically, the sample surface was first cleaned, then a black matte spray paint was uniformly applied to the sides, forming a uniform black paint film. Next, white matte paint was randomly sprayed onto the black paint film, creating a high-contrast random grayscale distribution image with white random spots on a black background on the sides. The sides were then allowed to air dry naturally, resulting in a sample with the random grayscale distribution image, designated as the first sample.

[0106] In some embodiments, a random grayscale distribution image with white background and black random speckles can also be prepared on the side of the sample. The order of spraying is changed to first spraying a layer of paint film on the sample with white spray material, and then randomly spraying black spray material on the paint film.

[0107] The prepared random grayscale distribution image can make the distinction between the sample boundary and the environmental background clearer during image capture; moreover, the subsequent black and white speckle images can be used to calculate the vibration attenuation amplitude based on DIC (digital image correlation technology) (data processing software is used for data processing), thereby improving the data processing efficiency of the embodiments of this application.

[0108] Optionally, in other embodiments, other high-contrast spray materials can be used to prepare random grayscale distribution images, as long as the speckle and the bottom surface can be clearly distinguished, which helps to observe the vibration attenuation of the first sample through the acquired images.

[0109] The amplitude data recording module 202 is used to apply a first displacement to the first sample through the vibration attenuation test device and then release it, while recording the amplitude change of the first sample from the release of the first displacement to complete rest, to obtain a vibration attenuation dataset describing the change of the amplitude of the first sample over time, and amplitude change data describing the change of the displacement of a preset monitoring point in the first sample over time.

[0110] In this embodiment of the application, a vibration attenuation testing device is used to fix one end of the first sample, apply a first displacement to the other end, and then release it.

[0111] The vibration attenuation test device was used to acquire images of the first specimen from the release of the first displacement to complete rest, and a vibration attenuation dataset was obtained.

[0112] While releasing the first displacement, the amplitude change at a preset monitoring point in the first sample is recorded to obtain the amplitude change data;

[0113] The attenuation curve construction module 203 is used to construct the vibration amplitude attenuation curve of the first sample based on the vibration attenuation dataset and the amplitude change data.

[0114] In this embodiment of the application, the obtained vibration attenuation dataset and amplitude change data are compared to determine the time from the release of the load to complete cessation of the first specimen and to construct the vibration amplitude attenuation curve of the first specimen.

[0115] The vibration amplitude attenuation curve of the first sample is as follows:

[0116]

[0117] In the formula, x is the mass displacement of the first sample, A is the complex amplitude of the mass displacement, ξ is the damping ratio, Ω is the preset undamped natural frequency of the single-degree-of-freedom system, t is the amplitude decay time, and α is the initial phase.

[0118] The damping loss factor calculation module 204 is used to calculate the damping loss factor of the first sample based on the vibration amplitude attenuation curve, so as to characterize the vibration attenuation characteristics of the first sample.

[0119] In this embodiment of the application, the vibration attenuation performance of the material is quantitatively determined based on the vibration amplitude attenuation curve and a preset damping loss factor calculation formula.

[0120] The damping loss factor is specifically:

[0121]

[0122] In the formula, γ is the damping loss factor.

[0123] Among them, for It is actually the natural logarithm of the ratio of the amplitudes of any two adjacent positive or negative peaks, and its specific expression is:

[0124]

[0125]

[0126] In the formula, T d For the vibration decay period, when ξ is relatively small, i.e., 1-ξ 2 When ≈1, the damping loss factor is 2ξ, at which point we have

[0127] In some embodiments, the amplitude data recording module 202 specifically comprises:

[0128] The vibration attenuation testing device is used to fix one end of the first specimen to prevent the first specimen from loosening during the test and causing the test to fail. Then, a certain displacement is applied to the other end of the first specimen through the vibration attenuation testing device.

[0129] Specifically, the vibration attenuation testing device includes a cylinder, a tightening device, a blocking device, a clamp, and clamping plates. The clamp and clamping plates hold one end of the first sample. By extending and retracting the cylinder and rotating the tightening device, the blocking device is fine-tuned and locked. Adjusting the blocking device to a certain angle applies displacement to the first sample. Adjusting the cylinder and tightening device ensures accurate setting of test conditions, improving the precision of the test results.

[0130] The fixture is customized according to the shape, size, and testing requirements of the first sample. It works with clamping plates to achieve quick and stable clamping, ensuring the stable position of the first sample during testing. The blocking device is designed as a rotatable structure, capable of rotating 90° under the drive of a cylinder, thereby releasing the sample and causing it to rebound and vibrate. The surface of the blocking device is also covered with a low-friction material, which reduces interference with the sample's rebound process and further improves the accuracy of the test results.

[0131] Optionally, in this embodiment of the application, a displacement of 12.5 mm is applied to the first sample, which is a plastic product.

[0132] After the blocking device rotates to the preset test angle, it is released to allow the first sample to rebound and vibrate. Simultaneously with the release of displacement of the first sample, the high-speed camera of the vibration attenuation testing device captures images of the first sample from the release of displacement to complete rest, recording the entire process of amplitude attenuation over time during release. By recording the amplitude of the first sample at different time points during the entire process from release of displacement to complete rest using the acquired images, a vibration attenuation dataset is obtained.

[0133] Specifically, when clamping the first sample, the parameters of the high-speed camera are first adjusted, the first sample is placed in the center of the camera lens, and the camera is started to record the entire process of the first sample from rebounding to complete stillness while releasing the blocking device.

[0134] In addition, to compare the vibration damping characteristics of multiple materials, the same displacement is usually applied to the samples corresponding to the multiple materials. By comparing the time it takes for these samples to bounce back to complete rest, the vibration damping characteristics of different materials can be qualitatively compared. The shorter the time, the better the vibration damping characteristics of the material.

[0135] Simultaneously with the release of displacement of the first specimen, the displacement change of a preset monitoring point on the first specimen relative to its initial position is recorded using a laser rangefinder of the vibration attenuation testing device throughout the entire time period from the release of the first displacement to complete rest, thus obtaining the amplitude change data. The monitoring point is selected from a random grayscale distribution image of the first specimen, and its initial position is the position of the monitoring point before the release of displacement.

[0136] Specifically, after the laser rangefinder is precisely calibrated and started, the laser beam of the laser rangefinder is focused on a preset monitoring point. As the first sample rebounds, the displacement change of the monitoring point relative to its initial position is continuously recorded throughout the entire process of the first sample rebounding to complete rest, thus obtaining the amplitude change data of the monitoring point throughout the entire process of the first sample rebounding.

[0137] The laser rangefinder is a high-precision non-contact measuring tool used to record the distance change of the first sample during its rebound process in real time, resulting in highly accurate test data and a fast response speed. Furthermore, compared to existing contact-based data acquisition devices, the laser rangefinder reduces the impact on test results through non-contact measurement.

[0138] This application also provides a vibration attenuation testing device for measuring the vibration attenuation performance of materials. The vibration attenuation testing device mainly includes a device calibration module, a displacement application module, and an amplitude measurement module. The device calibration module includes a metal base containing a shock-absorbing device, made of a high-strength, high-stability metal material, used to fix the displacement application module and the amplitude measurement module, ensuring stability and accuracy during the testing process. Furthermore, the metal base has an embedded shock-absorbing device to reduce the interference of external vibrations on the test results.

[0139] The displacement application module includes a cylinder, a tightening device, a blocking device, a clamp, and a clamping plate. It is used to fix the first sample using the clamp and clamping plate. The rotation angle of the blocking device is adjusted by controlling the cylinder and tightening device to apply or release a first displacement to the first sample, ensuring accurate setting of the test conditions. The clamp is meticulously designed according to the shape, size, and test requirements of the sample, perfectly conforming to the sample's contour for precise positioning. Simultaneously, the clamping plate is located inside the clamp, and through a fine adjustment and locking mechanism, it easily and securely clamps the sample within the clamp, preventing it from shifting or falling off during the test.

[0140] Furthermore, through precise adjustment of the tightening device, the cylinder is fixed in a position optimal for the testing requirements. At this point, a blocking device is cleverly positioned at one end of the sample, physically obstructing it to form a certain tilt angle. This design not only simulates the initial shape of the sample under stress but also prepares it for subsequent vibration rebound tests.

[0141] The amplitude measurement module includes a laser rangefinder and a camera, used to record the entire process of the first sample from the release of the first displacement to complete rest.

[0142] Implementing the embodiments of this application has the following beneficial effects:

[0143] This embodiment first prepares a high-contrast random grayscale distribution image using black and white spraying materials, which can more clearly show the subtle differences in vibration in subsequent experiments. Then, one end of the sample is fixed to reduce the interference of external vibration on the test results, and displacement is applied to the other end of the sample to simulate the stress state of the first sample. Then, the displacement is released to make the first sample vibrate, and the entire process of the first sample from vibration to rest is recorded by image acquisition and laser ranging. Test data can be obtained without contacting the sample, which improves the accuracy of the data. Then, the damping loss factor is obtained by collecting vibration attenuation data and amplitude change data to quantify the amplitude attenuation characteristics of the first sample. The test of the vibration attenuation characteristics of the material can be completed with simple operation, which is more efficient than traditional test methods and also ensures the accuracy of the test results.

[0144] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. In particular, it should be noted that any modifications, equivalent substitutions, or improvements made by those skilled in the art within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for characterizing the vibration damping properties of plastic materials, characterized in that, include: Random grayscale distribution images were prepared on the sample using black and white spray materials to obtain the first sample. A vibration attenuation testing device is used to apply a first displacement to a first specimen and then release it. Simultaneously, the amplitude change of the first specimen during the entire process from the release of the first displacement to complete rest is recorded. This yields a vibration attenuation dataset describing the amplitude change of the first specimen over time, and amplitude change data describing the displacement change of a preset monitoring point within the first specimen over time. Specifically, the vibration attenuation testing device is used to fix one end of the first specimen, apply a first displacement to the other end, and then release it. The device acquires images of the first specimen during the entire process from the release of the first displacement to complete rest, recording the amplitude at different time points to obtain the vibration attenuation dataset. During the entire time period from the release of the first displacement to complete rest, the side containing the random grayscale distribution image of the first specimen is placed in the center of the camera of the vibration attenuation testing device. Then, the laser beam of the vibration attenuation testing device is focused on the monitoring point, and the displacement change of the monitoring point during the entire process is recorded to obtain the amplitude change data. The monitoring point is selected from the random grayscale distribution image of the first sample; the initial position of the monitoring point is the position of the monitoring point before the first sample releases the first displacement; Based on the vibration attenuation dataset and the amplitude change data, a vibration amplitude attenuation curve for the first specimen is constructed. Based on the vibration amplitude attenuation curve, the damping loss factor of the first sample is calculated to characterize the vibration attenuation characteristics of the first sample.

2. The method for characterizing the vibration damping characteristics of plastic materials according to claim 1, characterized in that, The process of preparing a random grayscale distribution image on the sample using black and white spray paint to obtain the first sample is as follows: The random grayscale distribution image is determined according to the testing requirements; When the random grayscale distribution image is a black background with random white speckles, first use black spray to spray a layer of paint film on the sample, and then use white spray to randomly spray on the paint film to obtain the first sample; When the random grayscale distribution image is a white background with random black speckles, first use white spray to spray a layer of paint film on the sample, and then use black spray to randomly spray on the paint film to obtain the first sample.

3. The method for characterizing the vibration damping characteristics of plastic materials according to claim 1, characterized in that, The vibration amplitude attenuation curve of the first sample is as follows: ； In the formula, x Let be the mass displacement of the first sample. A Let be the complex amplitude of the mass displacement. ξ For the damping ratio, Ω The preset undamped natural frequency of the single-degree-of-freedom system. t The amplitude decay time, α This is the initial phase.

4. The method for characterizing the vibration damping characteristics of plastic materials according to claim 1, characterized in that, The damping loss factor is specifically: ； In the formula, γ Let be the damping loss factor. A 1. A 3 represents the amplitude of any two adjacent positive or negative peaks.

5. A characterization system for the vibration damping characteristics of plastic materials, characterized in that, include: The system includes modules for sample preparation, amplitude data recording, attenuation curve construction, damping loss factor calculation, displacement application, amplitude measurement, and device calibration. The sample preparation module is used to prepare a random grayscale distribution image on the sample using black and white spray materials to obtain the first sample. The amplitude data recording module is used to apply a first displacement to the first sample through the vibration attenuation test device and then release it, while recording the amplitude change of the first sample from the release of the first displacement to complete rest. This results in a vibration attenuation dataset describing the change of the amplitude of the first sample over time, and amplitude change data describing the change of the displacement of the preset monitoring point in the first sample over time. The vibration attenuation testing device includes a metal base with a damping device for fixing the displacement application module and the amplitude measurement module; the device calibration module includes a metal base with a damping device for fixing the displacement application module and the amplitude measurement module; the displacement application module includes a cylinder, a tightening device, a blocking device, a clamp, and a clamping plate for fixing the first sample by the clamp and clamping plate, and adjusting the rotation angle of the blocking device by controlling the cylinder and the tightening device to apply or release a first displacement to the first sample; the amplitude measurement module includes a laser rangefinder and a camera for recording the entire process of the first sample from releasing the first displacement to becoming completely stationary; The attenuation curve construction module is used to construct the vibration amplitude attenuation curve of the first sample based on the vibration attenuation dataset and the amplitude change data. The damping loss factor calculation module is used to calculate the damping loss factor of the first sample based on the vibration amplitude attenuation curve, so as to characterize the vibration attenuation characteristics of the first sample.

6. The characterization system for vibration damping characteristics of plastic materials according to claim 5, characterized in that, The first sample is fixed by clamps and clamping plates, and the rotation angle of the blocking device is adjusted by controlling the cylinder and tightening device to apply or release a first displacement to the first sample, specifically as follows: One end of the first sample is fixed using a clamp and a clamping plate, and the other end of the first sample is placed on the blocking device. The cylinder is driven by a rotating tightening device, and the blocking device is rotated under the action of the cylinder to apply displacement to the first sample. When the blocking device rotates to a preset test angle, the blocking device is controlled to release a displacement toward the first sample, so that the first sample begins to vibrate; wherein, the first displacement is determined by the test angle.

7. The characterization system for vibration damping characteristics of plastic materials according to claim 5, characterized in that, The recording of the entire process from the release of the first displacement to complete rest of the first sample is as follows: The camera captures images of the first sample from the release of the first displacement to complete rest, thus obtaining a vibration attenuation dataset. The laser beam of the laser rangefinder is focused on a preset monitoring point in the first sample, and the displacement change of the monitoring point is recorded by the laser beam to obtain amplitude change data.

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