Local phase identification method and experimental device for particle-elastic coupled vibration system

Abstract

The present invention provides a method and experimental device for identifying the local phase state of a particle-elastomer coupled vibration system, relating to the technical field of particle-elastomer coupled vibration technology. The present invention achieves localized actuation of a granular medium by applying a constant-amplitude swept-frequency excitation to the elastomer. Simultaneously, the submerged elastomer serves as a probe / sensor to identify phase changes in the granular medium. By establishing a theoretical model of the coupled system and conducting experimental verification, the present invention obtains a calibration relationship between kinetic parameters such as the dynamic effective mass of the vibrating elastomer in the immersed particle and the particle's local phase state, thereby enabling the elastomer to serve as an integrated driver-sensor device to identify the particle's local phase state.

Description

Technical Field

[0001] The present invention relates to the technical field of particle-elastic body coupled vibration, and in particular to a local phase state identification method and experimental device for a particle-elastic body coupled vibration system. Background Art

[0002] Existing research indicates that when a fluid vibrates in coupling with a structure, the effects can be simplified to the role of added mass. However, compared to fluid media, when granular matter vibrates in coupling with an elastomer, the elastomer and its neighboring granular media often exhibit very complex dynamic properties. Researchers studying the dynamic behavior of granular matter have mostly used external energy input through vibration or shear at rigid boundaries. When granular matter vibrates in coupling with an elastomer, especially an immersed elastomer, it exhibits more complex additional effects or nonlinear behavior, and the local phase properties within the three-dimensional granular matter cannot be directly observed experimentally.

[0003] The influence of particles on the dynamic performance of elastomeric structures, such as particle dampers and foundation beams, is a widely discussed topic in engineering. However, a unified theoretical model and experimental validation are still lacking. Consequently, establishing a simple and effective model for particle-elastomer coupled systems to identify and detect the local phase state of the system is extremely difficult. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a method and experimental device for identifying the local phase state of a particle-elastomer coupled vibration system; the method is implemented through an integrated drive-sensor approach, and the local phase state characteristics or local phase changes of the granular material are identified through the strain signal of the elastomer. Therefore, for the study of the local phase state characteristics of the granular material, the vibrating elastomer is both a driver, driving the granular material to undergo local phase changes, and a sensor, detecting the local phase state characteristics of the granular material through its own signal.

[0005] Actuation is achieved by applying simple harmonic excitations at varying force amplitudes and frequencies to an elastic body, causing it to vibrate and drive neighboring particles. Sensing involves identifying the local phase properties of particles by using the elastic body's vibrational morphology (strain-displacement reconstruction) and nonlinear vibration characteristics (jumps, chaos, bifurcations, etc.) derived from the dynamic strain signal on the elastic body (which can be obtained from a certain number of evenly distributed strain sensors). Elastomers, such as beams, require calibration as sensors. This is achieved using a coupled DEM-FEM numerical calculation method, combined with experimental verification, to calibrate specific elastic bodies.

[0006] The technical solutions of the present invention are as follows:

[0007] On the one hand, an experimental device for identifying the local phase state of a particle-elastic body coupled vibration system includes a glass box, a particle medium, a hollow elastic body, a wireless force sensor, a wireless acceleration sensor, and a wireless remote control linear motor;

[0008] The wireless remote-controlled linear motor is installed inside the hollow elastic body, the wireless force sensor is installed inside the hollow elastic body and above the wireless remote-controlled linear motor, and the wireless acceleration sensor is installed on the lower surface of the hollow elastic body;

[0009] The outer surface of the hollow elastic body is regular;

[0010] The glass box is firmly connected to the workbench, and the hollow elastic body is placed in the glass box as a free boundary;

[0011] The hollow elastic body is a split structure, and the outer shell of the hollow elastic body is formed by buckling two identical parts;

[0012] On the other hand, a method for identifying the local phase state of a particle-elastic body coupled vibration system is implemented based on the aforementioned experimental device for identifying the local phase state of a particle-elastic body coupled vibration system, and specifically includes the following steps:

[0013] Step 1: Use the DEM-FEM coupling calculation method to establish a numerical simulation model;

[0014] Step 2: Get the calibration dataset:

[0015] Step 2.1: Under the same particle size and particle layer thickness, control the amplitude of the excitation force on the hollow elastic body and adjust the excitation frequency from small to large and from large to small. Obtain the amplitude-frequency characteristic curves of the two frequency sweep paths, and extract the effective friction coefficient μ, inertia number I, and elastic body strain of the granular medium during the vibration process;

[0016] Step 2.2: Change the excitation force amplitude, repeat step 2.1, and perform two sets of repeated experiments;

[0017] Step 2.3: Change the thickness of the granular layer and repeat steps 2.1-2.2;

[0018] Step 2.4: Change the particle size and repeat steps 2.1 to 2.3;

[0019] Step 2.5: Construct a calibration data set using the obtained elastic body strain, effective friction coefficient, and inertia number data;

[0020] Step 3: Based on the elastic body strain, effective friction coefficient μ, inertia number I extracted from each working condition and the corresponding excitation, data fitting is performed to form a relationship function or curve between excitation-elastic body strain-particle rheology, and the local phase state of the particle is detected by strain.

[0021] The beneficial effects of adopting the above technical solution are:

[0022] 1. A method for measuring the local phase state of granular media is proposed, which solves the problem of difficulty in obtaining the phase state of particles when the elastic body and particles are coupled to vibrate;

[0023] 2. Drive-sensor integration: The hollow beam serves as both a drive and a sensor. Integrating the sensor inside the drive does not change the state of the particle system under local drive, eliminating the system error caused by the implanted sensor in conventional testing.

[0024] 3. Using wireless sensor design to reduce the impact of additional boundaries and sensor connections on granular media brought by wired design, improve recognition accuracy and reduce errors;

[0025] 4. The method is more reliable by using both numerical simulation and physical experiments to verify each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of a physical experiment model in an embodiment of the present invention;

[0027] In the figure, 1-glass box, 2-glass beads, 3-hollow beam;

[0028] Figure 2 The internal structure of the hollow beam in the embodiment of the present invention;

[0029] In the figure, 4-wireless remote control linear motor;

[0030] Figure 3 Schematic diagram of a numerical simulation model in an embodiment of the present invention;

[0031] Figure 4 Graph showing the relationship between the amplitude-frequency characteristic curve and μ-I rheology in prior research in an embodiment of the present invention;

[0032] in Figure 4 (a) is the amplitude-frequency characteristic curve, Figure 4 (b) is the μ-I rheological relationship diagram; DETAILED DESCRIPTION

[0033] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0034] This experimental method mainly studies the nonlinear vibration of the particle-beam coupling system by focusing on parameters such as the excitation force amplitude, excitation force frequency, particle layer thickness in the beam area, and particle size. In this experiment, the elastic body not only implements local oscillations on the neighboring particles, but also serves as a probe to identify the additional effects of the granular medium and its phase state.

[0035] On the one hand, an experimental device for identifying the local phase state of a particle-elastic body coupled vibration system includes: a glass box, a particle medium, a hollow elastic body (a soft metal or composite material plate, a beam, etc.), a wireless force sensor, a wireless acceleration sensor, and a wireless remote control linear motor;

[0036] The wireless remote-controlled linear motor is installed inside the hollow elastic body, the wireless force sensor is installed inside the hollow elastic body and above the wireless remote-controlled linear motor, and the wireless acceleration sensor is installed on the lower surface of the hollow elastic body;

[0037] The outer surface of the hollow elastomer is regular, and there is no additional boundary such as a measuring instrument to change the shape of the outer surface of the elastomer, which will not affect the state of the granular medium and is convenient for theoretical modeling.

[0038] The glass box is firmly connected to the workbench, and the hollow elastic body is placed in the glass box as a free boundary;

[0039] The hollow elastic body acts as a driver to locally drive the granular medium. The elastic body drives the neighboring particles through its own vibration, which is different from the vibration of the entire box to drive the particle system. It also acts as a probe / sensor to qualitatively determine the phase change of the granular medium.

[0040] The hollow elastic body is a split structure, and the outer shell of the hollow elastic body is formed by buckling two identical parts, which is convenient for disassembling and assembling the linear motor. The wireless remote control linear motor is fixed inside the hollow elastic body through ribs.

[0041] The experimental setup in this example is as follows Figure 1 As shown in Figure 3, the basic framework of the particle-elastic body coupled vibration system experiment is presented. The hollow elastic body uses a hollow beam 3, as shown in Figure 3. Figure 2 As shown, glass beads 2 are used as the granular medium, a linear exciter is used as the wireless remote-controlled linear motor 4, and a hollow beam is horizontally placed at the center of the glass box 1. In order to explore the size effect of the granular medium, three glass beads of different sizes are used in the experiment, and the particle sizes approximately obey the normal distribution.

[0042] A linear vibrator fixed inside the hollow beam applies simple harmonic excitation in the vertical direction, sweeping the frequency from 0Hz to 500Hz. A wireless force sensor is installed on the upper surface of the hollow beam, directly above the linear vibrator, to measure the force signal. A wireless accelerometer is installed at the bottom of the hollow beam cavity, directly below the linear vibrator, to measure the acceleration signal. The force and acceleration signals are recorded and analyzed using a signal receiver and a computer. The mass of the wireless remote-controlled linear motor, wireless force sensor, and wireless accelerometer is taken into account during the numerical modeling of the beam, thereby improving the accuracy of the numerical model calculations.

[0043] On the other hand, a method for identifying the local phase state of a particle-elastic body coupled vibration system is implemented based on the aforementioned experimental device for identifying the local phase state of a particle-elastic body coupled vibration system, and specifically includes the following steps:

[0044] Step 1: Use the DEM-FEM coupling calculation method to establish a numerical simulation model;

[0045] The numerical simulation model in this embodiment is as follows Figure 3 As shown in Figure 4, the effectiveness of the numerical simulation results is verified by comparing them with the test results under typical working conditions.

[0046] Step 2: Get the calibration dataset:

[0047] Step 2.1: Under the same particle size and particle layer thickness, control the amplitude of the excitation force on the hollow elastic body and adjust the excitation frequency from small to large and from large to small. Obtain the amplitude-frequency characteristic curves of the two frequency sweep paths, and extract the effective friction coefficient μ, inertia number I, and elastic body strain of the granular medium during the vibration process;

[0048] Step 2.2: Change the excitation force amplitude, repeat step 2.1, and perform two sets of repeated experiments;

[0049] Step 2.3: Change the thickness of the granular layer and repeat steps 2.1-2.2;

[0050] Step 2.4: Change the particle size and repeat steps 2.1 to 2.3;

[0051] Step 2.5: Construct a calibration data set using the obtained elastic body strain, effective friction coefficient, and inertia number data;

[0052] Step 3: According to the elastic body strain, effective friction coefficient μ and inertia number I extracted from each working condition and the corresponding excitation, data fitting is performed to form a relationship function or curve between excitation-elastic body strain-particle rheology, and the local phase state of the particle is detected by strain. Figure 4 In this embodiment, the amplitude-frequency characteristic curve is as follows: Figure 4 (a) shows the μ-I rheological relationship diagram. Figure 4 (b) shown.

[0053] The above description is merely a preferred embodiment of the present disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also encompass other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the above-mentioned inventive concept. For example, a technical solution formed by mutually replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in the embodiments of the present disclosure.

Claims

1. An experimental device for identifying local phase states of a particle-elastic body coupled vibration system, characterized in that: Including glass box, granular medium, hollow elastic body, wireless force sensor, wireless acceleration sensor, wireless remote control linear motor; The wireless remote control linear motor is installed inside the hollow elastic body, the wireless force sensor is installed inside the hollow elastic body and above the wireless remote control linear motor, and the wireless acceleration sensor is installed on the lower surface inside the hollow elastic body.

2. The local phase state identification experimental device of a particle-elastic body coupled vibration system according to claim 1, characterized in that: The outer surface of the hollow elastic body is regular.

3. The local phase state identification experimental device of a particle-elastic body coupled vibration system according to claim 1, characterized in that: The hollow elastic body is a split structure.

4. The local phase state identification experimental device of a particle-elastic body coupled vibration system according to claim 3, characterized in that: The split structure is as follows: the hollow elastic body is formed by buckling two identical parts.

5. The local phase state identification experimental device of a particle-elastic body coupled vibration system according to claim 1, characterized in that: The wireless remote control linear motor is fixed inside the hollow elastic body through ribs.

6. The experimental device for identifying local phase states of a particle-elastic body coupled vibration system according to claim 1, characterized in that: The glass box is firmly connected to the workbench, and the hollow elastic body is placed in the glass box and serves as a free boundary.

7. An experimental method for identifying the local phase state of a particle-elastic body coupled vibration system, implemented based on the experimental device for identifying the local phase state of a particle-elastic body coupled vibration system according to claim 1, characterized in that: The specific steps include: Step 1: Use the DEM-FEM coupling calculation method to establish a numerical simulation model; Step 2: Get the calibration dataset: Step 3: Based on the elastic body strain, effective friction coefficient μ, inertia number I extracted from each working condition and the corresponding excitation, data fitting is performed to form a relationship function or curve between excitation-elastic body strain-particle rheology, and the local phase state of the particle is detected by strain.

8. The experimental method for identifying the local phase state of a particle-elastic body coupled vibration system according to claim 7, characterized in that: The step 2 specifically includes the following steps: Step 2.1: Under the same particle size and particle layer thickness, control the amplitude of the excitation force on the hollow elastic body and adjust the excitation frequency from small to large and from large to small. Obtain the amplitude-frequency characteristic curves of the two frequency sweep paths, and extract the effective friction coefficient μ, inertia number I, and elastic body strain of the granular medium during the vibration process; Step 2.2: Change the excitation force amplitude, repeat step 2.1, and perform two sets of repeated experiments; Step 2.3: Change the thickness of the granular layer and repeat steps 2.1-2.2; Step 2.4: Change the particle size and repeat steps 2.1 to 2.3; Step 2.5: Construct a calibration data set using the obtained elastic body strain, effective friction coefficient, and inertia number data.

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