Method and system for characterizing vibration attenuation characteristic of plastic material

Abstract

The invention discloses a characterization method and system for the vibration attenuation characteristic of a plastic material, and belongs to the field of material detection.The method comprises the steps that a black spraying material and a white spraying material are used for preparing a random gray level distribution image on a sample, and a first sample is obtained; the method comprises the following steps: applying a first displacement to a first sample through a vibration attenuation testing device, then releasing the first sample, and recording the amplitude change of the first sample in the whole process from releasing the first displacement to completely static to obtain a vibration attenuation data set describing the change of the amplitude of the first sample along with time; constructing a vibration amplitude attenuation curve of the first sample according to the amplitude variation data of the displacement variation of the preset monitoring point in the first sample along with the time variation; and calculating a damping loss factor of the first sample according to the vibration amplitude attenuation curve so as to represent the vibration attenuation characteristic of the first sample. The amplitude attenuation condition of the material is recorded through the camera and the laser instrument, the test data can be quickly obtained, and the test cost is reduced.

Description

Technical Field

[0001] The present application belongs to the field of material testing, and specifically relates to a method and system for characterizing the vibration attenuation characteristics of plastic materials. Background Art

[0002] Mechanical vibration can cause instability in the structural stress conditions of materials, leading to mechanical fatigue. Long-term exposure to vibration can lead to fatigue damage in structural materials, ultimately causing material failure. Furthermore, mechanical vibration generates noise and vibration, causing discomfort in people's living and working environments. Therefore, when designing high-speed mechanical products, materials with high vibration attenuation properties are often required to overcome the reduced service life and comfort of the product caused by vibration.

[0003] The vibration attenuation characteristics of a material reflect its ability to resist external energy loss. Mechanical vibration energy loss, caused by internal factors such as friction between molecules and grains during vibration, is generally characterized by damping. Currently, a dynamic mechanical analyzer (DMA) is commonly used to test the loss factor (tanδ) of a material to study the vibration attenuation performance of plastic materials. While the loss factor can effectively detect differences in vibration attenuation performance between different substrates, subtle differences between materials modified with different formulations based on the same substrate are difficult to visualize. Furthermore, using DMA to characterize material vibration characteristics requires specialized instrumentation, resulting in high testing costs and a long test cycle. 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 a laser instrument, the vibration attenuation characteristics of different materials can be quickly obtained and the testing cost can be reduced.

[0005] A first aspect of the present application provides a method for characterizing the vibration attenuation characteristics of a plastic material, the method comprising:

[0006] Using black spray material and white spray material to prepare a random grayscale distribution image on the sample to obtain a first sample;

[0007] A first displacement is applied to a first specimen by a vibration attenuation testing device and then released, while recording the amplitude change of the first specimen from the release of the first displacement to complete rest, thereby obtaining a vibration attenuation data set 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;

[0008] constructing a vibration amplitude attenuation curve of the first sample based on the vibration attenuation data set and the amplitude change data;

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

[0010] The above scheme first prepares a high-contrast random grayscale distribution image through black and white spraying, which can more clearly show the subtle differences in vibration in subsequent tests; then fixes one end of the specimen to reduce the interference of external vibration on the test results, and applies displacement to the other end of the specimen to simulate the stress state of the first specimen; then releases the displacement to cause the first specimen to vibrate, and uses image acquisition and a laser rangefinder to record the entire process from vibration to stillness of the first specimen and a monitoring point on the first specimen respectively. Test data can be obtained without contacting the specimen, which improves the data accuracy; then, the damping loss factor is obtained from the collected vibration attenuation data set and amplitude change data to quantify the amplitude attenuation characteristics of the first specimen. The vibration attenuation characteristics of the material can be tested with only simple operations. Compared with traditional testing methods, the test efficiency is higher and the accuracy of the test results is guaranteed.

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

[0012] Determine the random grayscale distribution image according to test requirements;

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

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

[0015] The above scheme prepares a random grayscale distribution image by spraying materials with high contrast between black and white colors, which can more intuitively observe the vibration changes of the material in subsequent vibration tests and obtain accurate test data.

[0016] In one possible implementation of the first aspect, a first displacement is applied to a first specimen using a vibration attenuation testing device and then released, while simultaneously recording the amplitude change of the first specimen from the release of the first displacement to complete rest. 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 are obtained. Specifically, the following are obtained:

[0017] Using a vibration attenuation test device, one end of a first specimen is fixed, a first displacement is applied to the other end, and then released;

[0018] Capturing images of the entire process of the first sample from the release of the first displacement to complete rest using a vibration attenuation testing device, recording the amplitudes of the first sample at different time points during the entire process of the first sample from the release of the first displacement to complete rest, to obtain the vibration attenuation dataset;

[0019] The displacement change of a preset monitoring point in the first specimen relative to the initial position of the monitoring point is recorded during the entire time period from the release of the first displacement to the complete stillness of the first specimen to obtain the amplitude change data; wherein the monitoring point is selected from the random grayscale distribution image of the first specimen; and the initial position of the monitoring point is the position of the monitoring point before the first specimen releases the first displacement.

[0020] The above scheme first fixes one end of the first specimen to ensure that it does not shift during the subsequent vibration process, which could affect the test results. A certain displacement is then applied to the other end and released, simulating the material's stress process and recording the impact of the resulting vibration on the material structure, generating a vibration attenuation dataset and amplitude change data, respectively. Because both types of test data are collected contactlessly, interference from contact on the test results is reduced, enabling fast and accurate results.

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

[0022] Place the side of the first sample where the random grayscale distribution image is located in the center of the camera of the vibration attenuation testing device, then focus the laser beam of the vibration attenuation testing device on the monitoring point, and record the displacement change of the monitoring point during the entire process to obtain the amplitude change data.

[0023] In a possible implementation method of the first aspect, the vibration amplitude attenuation curve of the first sample is specifically:

[0024]

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

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

[0027]

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

[0029] A second aspect of the present application provides a system for characterizing vibration attenuation characteristics of a plastic material, 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 spray material and white spray material to obtain a first sample;

[0031] The amplitude data recording module is used to apply a first displacement to the first specimen through a vibration attenuation testing device and then release it, while recording the amplitude change of the first specimen from the release of the first displacement to the complete rest, thereby obtaining 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;

[0032] The attenuation curve construction module is used to construct a vibration amplitude attenuation curve of the first sample according to the vibration attenuation data set and the amplitude change data;

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

[0034] In a possible implementation of the second aspect, the device further includes: a vibration attenuation testing device;

[0035] Wherein, the vibration attenuation test device includes a device calibration module, a displacement application module and an amplitude measurement module;

[0036] The device calibration module includes a metal base including a shock absorbing device for fixing the displacement applying module and the amplitude measuring module;

[0037] The displacement applying module includes a cylinder, a tightening device, a blocking device, a clamp and a clamping piece, and is used to fix the first specimen through the clamp and the clamping piece, 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 specimen;

[0038] The amplitude measurement module includes a laser rangefinder and a camera, and is used to record the entire process of the first sample from releasing the first displacement to completely stopping.

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

[0040] Fix one end of the first specimen using a clamp and a clamping piece, and place the other end of the first specimen on the blocking device;

[0041] The cylinder is driven by rotating the tightening device, and the blocking device is rotated by the action of the cylinder to apply displacement to the first specimen;

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

[0043] In a possible implementation of the second aspect, the entire process of the first sample from releasing the first displacement to being completely still is recorded, specifically as follows:

[0044] The camera is used to capture images of the entire process of the first sample from the release of the first displacement to the complete stillness, thereby obtaining a vibration attenuation data set;

[0045] The laser beam of the laser rangefinder is focused on a preset monitoring point in the first sample, and the monitoring point is recorded by the laser beam to obtain amplitude change data. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0047] Figure 1 This is a schematic diagram of a specific process of a method for characterizing the vibration attenuation characteristics of a plastic material provided in one embodiment of the present application;

[0048] Figure 2 This is a sample rebound diagram illustrating a method for characterizing the vibration attenuation characteristics of a plastic material provided in one embodiment of the present application;

[0049] Figure 3 This is a random grayscale distribution image of a method for characterizing the vibration attenuation characteristics of a plastic material provided in one embodiment of the present 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 provided in one embodiment of the present application;

[0051] Figure 5 is a vibration attenuation curve diagram of a method for characterizing the vibration attenuation characteristics of a plastic material provided in one embodiment of the present application;

[0052] Figure 6This is a panoramic view of a testing device for a method for characterizing the vibration attenuation characteristics of a plastic material provided in one embodiment of the present application;

[0053] Figure 7 This is a front view of a testing device for a method for characterizing the vibration attenuation characteristics of a plastic material provided in one embodiment of the present application;

[0054] Figure 8 This is a side view of a testing device for a method for characterizing the vibration attenuation characteristics of a plastic material provided in one embodiment of the present application;

[0055] Figure 9 This is a specific structural diagram of a system for characterizing the vibration attenuation characteristics of a plastic material provided in a certain embodiment of the present application. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

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

[0058] First embodiment

[0059] Mechanical vibrations of materials caused by external factors can cause uneven force on the material structure, which can cause damage to the material in severe cases, reducing the lifespan and use effect of products made of the material. Therefore, when manufacturing high-speed mechanical products, materials are often required to have higher vibration attenuation properties to overcome the impact of vibration on the product. The vibration attenuation characteristics of a material can reflect the material's ability to resist external energy loss, and the damping loss factor is commonly used to characterize the vibration attenuation characteristics. Although the damping loss factor can effectively show the differences in vibration attenuation characteristics of different materials, the slight differences between materials modified with different formulas of the same matrix are still difficult to intuitively characterize. Therefore, the main research direction of the embodiments of this application is how to quickly obtain the damping loss factors of different materials at a lower experimental cost to more intuitively characterize the vibration attenuation characteristics.

[0060] like Figure 1 As shown, Figure 1 A specific flow chart of a method for characterizing the vibration attenuation characteristics of a plastic material is provided for one embodiment of the present application. The method for characterizing the vibration attenuation characteristics of the plastic material of this embodiment includes steps S1 to S4, which are described in detail as follows:

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

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

[0063] Use black and white spray paints to evenly spray the sides of the specimen to create a high-contrast random grayscale distribution image. First, clean the specimen surface. Then, use black matte spray paint to evenly spray the sides, forming a uniform black film. Next, use white spray paint to randomly spray white matte paint over the black film, creating a high-contrast random grayscale distribution image with random white speckles on a black background. Allow the sides to air dry and set aside. This will yield a specimen with a random grayscale distribution image, designated as the first specimen.

[0064] In some embodiments, a random grayscale distribution image of random black speckles on a white background can also be prepared on the side of the sample, and 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 the paint film with black spray material.

[0065] The prepared random grayscale distribution image can make the distinction between the sample boundary and the environmental background clearer during image capture; and the subsequently captured black and white speckle image 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 embodiment of the present application.

[0066] Optionally, in other embodiments, other spray materials with high color contrast may 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 subsequent collected images.

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

[0068] In an embodiment of the present application, a vibration attenuation test device is used to fix one end of the first specimen to prevent the first specimen from loosening during the test and causing test failure, and then a certain displacement is applied to the other end of the first specimen by the vibration attenuation test device.

[0069] Specifically, the vibration attenuation test device includes a cylinder, a tightening device, a blocking device, a fixture, and a clamping plate. The fixture and clamping plate clamp one end of the first specimen. By extending and retracting the cylinder and rotating the tightening device, the blocking device is fine-tuned and locked. After adjusting the blocking device to a specific angle, the first specimen is displaced. Adjusting the cylinder and tightening device ensures accurate test conditions and improves the accuracy of test results.

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

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

[0072] After the blocking device rotates to the preset test angle, it is released, causing the first specimen to rebound and vibrate. As the first specimen releases its displacement, the vibration attenuation test device's high-speed camera captures images of the entire process from the release of the first displacement to complete rest. This process records the entire process of the first specimen's amplitude decaying over time during the release process. The captured images record the amplitude of the first specimen at different time points throughout the entire process from the release of the first displacement to complete rest, generating a vibration attenuation dataset.

[0073] Specifically, when clamping the first sample, first adjust the parameters of the high-speed camera, place the first sample in the center of the camera lens, and simultaneously release the blocking device to start the camera to record the entire process of the first sample from rebound to complete stillness.

[0074] In addition, how to compare the vibration attenuation characteristics of multiple materials is generally to apply the same displacement to the corresponding specimens of multiple materials. By comparing the time from rebound to complete rest of these specimens, the vibration attenuation characteristics of different materials can be qualitatively compared. The shorter the time, the better the vibration attenuation characteristics of the material.

[0075] While the first specimen is releasing its displacement, a laser rangefinder of the vibration attenuation testing apparatus is used to record the displacement change of a preset monitoring point on the first specimen relative to the initial position of the monitoring point during the entire period from the release of the first displacement to the complete rest of the first specimen, thereby obtaining the amplitude change data. The monitoring point is selected from a random grayscale distribution image of the first specimen, and the initial position of the monitoring point is the position of the monitoring point before the first specimen is released from its displacement.

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

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

[0078] Figure 2 The following diagrams illustrate sample rebound in accordance with an embodiment of the present application. From left to right, they depict the entire process of a first sample being displaced by a blocking device and rebounding during the release of the displacement. The first and second diagrams illustrate how a certain displacement is applied to the first sample. The third diagram shows the release of the displacement, and the initial rebound of the first sample in the fourth and fifth diagrams. The sample's rebound process is recorded using a laser rangefinder and a camera.

[0079] Figure 3 The random grayscale distribution images of three different material samples are displayed, namely the side black background and white spot images of PPS (polyphenylene sulfide material), 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. The green color in the figure represents the laser displacement sensor, the light blue strip represents the specimen, and a random grayscale distribution image is displayed on the side of the specimen. The monitoring points are located on the upper surface of the specimen and are selected based on their distance from the specimen clamping end. A camera is used to capture high-definition images of the random grayscale distribution image during the rebound process.

[0081] Step S3: constructing a vibration amplitude attenuation curve of the first sample according to the vibration attenuation data set and the amplitude variation data.

[0082] In an embodiment of the present application, the obtained vibration attenuation data set and amplitude change data are compared to determine the time from load release to complete stop of the first specimen and construct a vibration amplitude attenuation curve of the first specimen.

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

[0084]

[0085] Where x is the mass displacement of the first specimen, A is the complex amplitude of the mass displacement, ξ is the damping ratio, Ω is the undamped natural frequency of the preset 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 according to the vibration amplitude attenuation curve to characterize the vibration attenuation characteristics of the first sample.

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

[0088] The damping loss factor is specifically:

[0089]

[0090] Wherein, γ is the damping loss factor.

[0091] Among them, for In fact, it is the natural logarithm of the ratio of the amplitudes of any two adjacent positive or negative peaks. The specific expression is:

[0092]

[0093] Where, T d is the vibration attenuation period, when ξ is relatively small, i.e. 1-ξ 2 ≈1, the damping loss factor is 2ξ, then we have

[0094] In order to better compare the vibration attenuation performance of different materials, Figure 4 The following diagram shows vibration attenuation curves for two specimens: the purple line represents specimen 4#-2, and the blue line represents specimen 2#-1. These two specimens were injection-molded TLCP specimens with different formulations, and the specimen dimensions were ISO 527 Type 1A tensile specimens. Within the time period shown in the figure, the blue line shows a significantly greater change in vibration attenuation than the purple line, indicating that specimen 4#-2 exhibits superior vibration attenuation performance to specimen 2#-1.

[0095] The present application also provides a vibration attenuation test device for measuring the vibration attenuation performance of a material. The vibration attenuation test device primarily comprises 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. This base is used to secure the displacement application module and amplitude measurement module, ensuring stability and accuracy during testing. Furthermore, the metal base is embedded with a shock-absorbing device to reduce interference from 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, which are used to fix the first specimen through the clamp and the clamping plate. The rotation angle of the blocking device is adjusted by controlling the cylinder and the tightening device to apply or release the first displacement to the first specimen, ensuring the accurate setting of the test conditions. The clamp is carefully designed according to the shape, size and test requirements of the specimen, and can perfectly fit the contour of the specimen to achieve precise positioning. At the same time, the clamp is configured inside the clamp. Through subtle adjustments and locking mechanisms, it can easily and firmly clamp the specimen in the clamp to prevent it from shifting or falling off during the test.

[0097] Furthermore, through precise adjustment of the tightening device, the cylinder was secured in a position optimal for the test requirements. A blocking device was cleverly placed at one end of the specimen, physically blocking it and causing it to tilt at a specific angle. This design not only simulated the specimen's initial shape under stress but also prepared it for subsequent vibration rebound testing.

[0098] The amplitude measurement module includes a laser rangefinder and a camera, and is used to record the entire process of the first sample from releasing the first displacement to completely stopping.

[0099] The present application provides Figure 5 、 6 ,7 respectively show the panorama, front and side of the vibration attenuation test device. 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 piece, and 9 is a fixture.

[0100] The implementation of the embodiments of the present application has the following beneficial effects:

[0101] In the embodiment of the present application, a high-contrast random grayscale distribution image is first prepared by spraying black and white materials, which can more clearly show the slight differences in vibration in subsequent tests; 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 cause the first sample to vibrate, and the entire process of the first sample from vibration to stillness is recorded through image acquisition and laser ranging. The test data can be obtained without contacting the sample, which improves the accuracy of the data; then, the damping loss factor is obtained through the collected vibration attenuation data set 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 only simple operations. Compared with traditional testing methods, the test efficiency is higher and the accuracy of the test results is guaranteed.

[0102] Second embodiment

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

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

[0105] Use black and white spray paints to evenly spray the sides of the specimen to create a high-contrast random grayscale distribution image. First, clean the specimen surface. Then, use black matte spray paint to evenly spray the sides, forming a uniform black film. Next, use white spray paint to randomly spray white matte paint over the black film, creating a high-contrast random grayscale distribution image with random white speckles on a black background. Allow the sides to air dry and set aside. This will yield a specimen with a random grayscale distribution image, designated as the first specimen.

[0106] In some embodiments, a random grayscale distribution image of random black speckles on a white background can also be prepared on the side of the sample, and 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 the paint film with black spray material.

[0107] The prepared random grayscale distribution image can make the distinction between the sample boundary and the environmental background clearer during image capture; and the subsequently captured black and white speckle image 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 embodiment of the present application.

[0108] Optionally, in other embodiments, other spray materials with high color contrast may 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 subsequent collected images.

[0109] The amplitude data recording module 202 is used to apply a first displacement to the first specimen through a vibration attenuation testing device and then release it, while recording the amplitude change of the first specimen from the release of the first displacement to complete stillness, thereby obtaining 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.

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

[0111] The vibration attenuation test device is used to collect images of the entire process of the first sample from the release of the first displacement to the complete stillness to obtain a vibration attenuation data set.

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

[0113] The attenuation curve construction module 203 is used to construct a vibration amplitude attenuation curve of the first sample according to the vibration attenuation data set and the amplitude change data.

[0114] In an embodiment of the present application, the obtained vibration attenuation data set and amplitude change data are compared to determine the time from load release to complete stop of the first specimen and construct a vibration amplitude attenuation curve of the first specimen.

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

[0116]

[0117] Where x is the mass displacement of the first specimen, A is the complex amplitude of the mass displacement, ξ is the damping ratio, Ω is the undamped natural frequency of the preset 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 configured to calculate the damping loss factor of the first sample according to the vibration amplitude attenuation curve, so as to characterize the vibration attenuation characteristics of the first sample.

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

[0120] The damping loss factor is specifically:

[0121]

[0122] Wherein, γ is the damping loss factor.

[0123] Among them, for In fact, it is the natural logarithm of the ratio of the amplitudes of any two adjacent positive or negative peaks. The specific expression is:

[0124]

[0125]

[0126] Where, T d is the vibration attenuation period, when ξ is relatively small, i.e. 1-ξ 2 ≈1, the damping loss factor is 2ξ, then we have

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

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

[0129] Specifically, the vibration attenuation test device includes a cylinder, a tightening device, a blocking device, a fixture, and a clamping plate. The fixture and clamping plate clamp one end of the first specimen. By extending and retracting the cylinder and rotating the tightening device, the blocking device is fine-tuned and locked. After adjusting the blocking device to a specific angle, the first specimen is displaced. Adjusting the cylinder and tightening device ensures accurate test conditions and improves the accuracy of test results.

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

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

[0132] After the blocking device rotates to the preset test angle, it is released, causing the first specimen to rebound and vibrate. As the first specimen releases its displacement, the vibration attenuation test device's high-speed camera captures images of the entire process from the release of the first displacement to complete rest. This process records the entire process of the first specimen's amplitude decaying over time during the release process. The captured images record the amplitude of the first specimen at different time points throughout the entire process from the release of the first displacement to complete rest, generating a vibration attenuation dataset.

[0133] Specifically, when clamping the first sample, first adjust the parameters of the high-speed camera, place the first sample in the center of the camera lens, and simultaneously release the blocking device to start the camera to record the entire process of the first sample from rebound to complete stillness.

[0134] In addition, how to compare the vibration attenuation characteristics of multiple materials is generally to apply the same displacement to the corresponding specimens of multiple materials. By comparing the time from rebound to complete rest of these specimens, the vibration attenuation characteristics of different materials can be qualitatively compared. The shorter the time, the better the vibration attenuation characteristics of the material.

[0135] While the first specimen is releasing its displacement, a laser rangefinder of the vibration attenuation testing apparatus is used to record the displacement change of a preset monitoring point on the first specimen relative to the initial position of the monitoring point during the entire period from the release of the first displacement to the complete rest of the first specimen, thereby obtaining the amplitude change data. The monitoring point is selected from a random grayscale distribution image of the first specimen, and the initial position of the monitoring point is the position of the monitoring point before the first specimen is released from its displacement.

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

[0137] The laser rangefinder is a high-precision, non-contact measurement tool used to record the distance changes of the first specimen during its rebound process in real time. The resulting test data is highly accurate and has a fast response speed. Furthermore, compared to existing contact data acquisition devices, the laser rangefinder's non-contact measurement can reduce the impact on test results.

[0138] The present application also provides a vibration attenuation test device for measuring the vibration attenuation performance of a material. The vibration attenuation test device primarily comprises 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. This base is used to secure the displacement application module and amplitude measurement module, ensuring stability and accuracy during testing. Furthermore, the metal base is embedded with a shock-absorbing device to reduce interference from 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, which are used to fix the first specimen through the clamp and the clamping plate. The rotation angle of the blocking device is adjusted by controlling the cylinder and the tightening device to apply or release the first displacement to the first specimen, ensuring the accurate setting of the test conditions. The clamp is carefully designed according to the shape, size and test requirements of the specimen, and can perfectly fit the contour of the specimen to achieve precise positioning. At the same time, the clamp is configured inside the clamp. Through subtle adjustments and locking mechanisms, it can easily and firmly clamp the specimen in the clamp to prevent it from shifting or falling off during the test.

[0140] Furthermore, through precise adjustment of the tightening device, the cylinder was secured in a position optimal for the test requirements. A blocking device was cleverly placed at one end of the specimen, physically blocking it and causing it to tilt at a specific angle. This design not only simulated the specimen's initial shape under stress but also prepared it for subsequent vibration rebound testing.

[0141] The amplitude measurement module includes a laser rangefinder and a camera, and is used to record the entire process of the first sample from releasing the first displacement to completely stopping.

[0142] The implementation of the embodiments of the present application has the following beneficial effects:

[0143] In the embodiment of the present application, a high-contrast random grayscale distribution image is first prepared by spraying black and white materials, which can more clearly show the slight differences in vibration in subsequent tests; 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 cause the first sample to vibrate, and the entire process of the first sample from vibration to stillness is recorded through image acquisition and laser ranging. The test data can be obtained without contacting the sample, which improves the accuracy of the data; then, the damping loss factor is obtained through the collected vibration attenuation data set 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 only simple operations. Compared with traditional testing methods, the test efficiency is higher and the accuracy of the test results is guaranteed.

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

Claims

1. A method for characterizing the vibration attenuation characteristics of a plastic material, characterized in that: include: A random grayscale distribution image is prepared on the sample using black spray material and white spray material to obtain a first sample; A first displacement is applied to a first specimen using a vibration attenuation testing device and then released. The amplitude change of the first specimen from the release of the first displacement to complete rest is recorded, thereby obtaining 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. constructing a vibration amplitude attenuation curve of the first sample based on the vibration attenuation data set and the amplitude change data; The damping loss factor of the first sample is calculated according to the vibration amplitude attenuation curve to characterize the vibration attenuation characteristics of the first sample.

2. The method for characterizing the vibration attenuation characteristics of plastic materials according to claim 1, characterized in that: The black spray material and the white spray material are used to prepare a random grayscale distribution image on the sample to obtain the first sample, specifically: Determine the random grayscale distribution image according to test requirements; When the random grayscale distribution image is a random speckle with white background on a black background, a layer of paint film is first sprayed on the sample using a black spray material, and then a white spray material is randomly sprayed on the paint film to obtain a first sample; When the random grayscale distribution image is a random speckle with black on a white background, a layer of paint film is first sprayed on the sample using white spray material, and then black spray material is randomly sprayed on the paint film to obtain a first sample.

3. The method for characterizing the vibration attenuation characteristics of a plastic material according to claim 1, wherein: The vibration attenuation testing device applies a first displacement to the first specimen and then releases it, and simultaneously records the amplitude change of the first specimen from the release of the first displacement to complete rest, thereby obtaining 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: Using a vibration attenuation test device, fix one end of a first specimen, apply a first displacement to the other end, and then release the specimen; Capturing images of the entire process of the first sample from the release of the first displacement to complete rest using a vibration attenuation testing device, recording the amplitudes of the first sample at different time points during the entire process of the first sample from the release of the first displacement to complete rest, to obtain the vibration attenuation dataset; The displacement change of a preset monitoring point in the first specimen relative to the initial position of the monitoring point is recorded during the entire time period from the release of the first displacement to the complete stillness of the first specimen to obtain the amplitude change data; wherein the monitoring point is selected from the random grayscale distribution image of the first specimen; and the initial position of the monitoring point is the position of the monitoring point before the first specimen releases the first displacement.

4. The method for characterizing the vibration attenuation characteristics of a plastic material according to claim 3, wherein: The recording of the displacement change of a preset monitoring point in the first sample relative to the initial position of the monitoring point to obtain the amplitude change data is specifically as follows: The side of the first sample where the random grayscale distribution image is located is placed in the center of the camera of the vibration attenuation testing device. The laser beam of the vibration attenuation testing device is then 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.

5. The method for characterizing the vibration attenuation characteristics of a plastic material according to claim 1, wherein: The vibration amplitude attenuation curve of the first sample is specifically: Where x is the mass displacement of the first specimen, A is the complex amplitude of the mass displacement, ξ is the damping ratio, Ω is the undamped natural frequency of the preset single-degree-of-freedom system, t is the amplitude decay time, and α is the initial phase.

6. The method for characterizing the vibration attenuation characteristics of a plastic material according to claim 1, wherein: The damping loss factor is specifically: Wherein, γ is the damping loss factor, and A1 and A3 are the amplitudes of any two adjacent positive or negative peaks.

7. A system for characterizing vibration attenuation characteristics of plastic materials, characterized in that: include: Sample preparation module, amplitude data recording module, attenuation curve construction module and damping loss factor calculation module; The sample preparation module is used to prepare a random grayscale distribution image on the sample using black spray material and white spray material to obtain a first sample; The amplitude data recording module is used to apply a first displacement to the first specimen through a vibration attenuation testing device and then release it, while recording the amplitude change of the first specimen from the release of the first displacement to the complete rest, thereby obtaining 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; The attenuation curve construction module is used to construct a vibration amplitude attenuation curve of the first sample according to the vibration attenuation data set and the amplitude change data; The damping loss factor calculation module is used to calculate the damping loss factor of the first sample according to the vibration amplitude attenuation curve to characterize the vibration attenuation characteristics of the first sample.

8. The system for characterizing vibration attenuation characteristics of plastic materials according to claim 7, wherein: Also includes: Vibration attenuation test device; Wherein, the vibration attenuation test device includes a device calibration module, a displacement application module and an amplitude measurement module; The device calibration module includes a metal base including a shock absorbing device for fixing the displacement applying module and the amplitude measuring module; The displacement applying module includes a cylinder, a tightening device, a blocking device, a clamp, and a clamping piece, and is used to fix the first specimen through the clamp and the clamping piece, 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 specimen; The amplitude measurement module includes a laser rangefinder and a camera, and is used to record the entire process of the first sample from releasing the first displacement to completely stopping.

9. The system for characterizing vibration attenuation characteristics of plastic materials according to claim 8, wherein: The first sample is fixed by the clamp and the clamping piece, and the rotation angle of the blocking device is adjusted by controlling the cylinder and the tightening device to apply or release the first displacement to the first sample, specifically: Fix one end of the first specimen using a clamp and a clamping piece, and place the other end of the first specimen on the blocking device; The air cylinder is driven by rotating the tightening device, and the blocking device is rotated by the action of the air cylinder to apply displacement to the first specimen; When the blocking device rotates to a preset test angle, the blocking device is controlled to release the displacement toward the first sample, so that the first sample starts to vibrate; wherein the first displacement is determined by the test angle.

10. The system for characterizing vibration attenuation characteristics of plastic materials according to claim 8, wherein: The entire process of recording the first sample from the release of the first displacement to complete rest is specifically as follows: The camera is used to capture images of the entire process of the first sample from the release of the first displacement to the complete stillness, thereby obtaining a vibration attenuation data set; The laser beam of the laser rangefinder is focused on a preset monitoring point in the first sample, and the monitoring point is recorded by the laser beam to obtain amplitude change data.

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