A multimodal vibration suppression device and method

Abstract

This application discloses a multimodal vibration suppression device and method. The device includes: an elastic column with its bottom end connected to a vibrating structure; an additional mass block disposed at the top of the elastic column, the elastic column and the additional mass block being used to suppress the lower frequencies of the multimodal vibrations generated by the vibrating structure; a piezoelectric unit disposed on the vibrating structure; and a piezoelectric shunt circuit electrically connected to the piezoelectric unit, the piezoelectric unit and the piezoelectric shunt circuit being used to suppress the higher frequencies of the multimodal vibrations generated by the vibrating structure. This application employs an electromechanical combination approach, overcoming the problems of excessively large geometric dimensions and additional mass, and overly complex structures, caused by dynamic vibration absorbers controlling multimodal vibrations. It also avoids the problem of overly redundant shunt circuits in piezoelectric shunt control of multimodal vibrations.

Description

Technical Field

[0001] This application relates to the field of vibration control technology, and in particular to a multimodal vibration suppression device and method. Background Technology

[0002] Vibration is a common physical phenomenon. In some scenarios, vibration is harmful, causing a series of adverse effects such as noise, loosening, and accelerated wear. Therefore, vibration needs to be suppressed in these scenarios.

[0003] A common vibration suppression method involves transferring the mechanical energy of structural vibrations to a dynamic vibration absorber through resonance, thereby suppressing structural vibrations. However, if a dynamic vibration absorber is used to suppress multiple modal frequencies of a controlled structure simultaneously, the absorber's mass will inevitably be relatively large, potentially reaching 10%–20% of the main vibration system's mass in some scenarios. This severely limits its further application in engineering practice. Piezoelectric shunt technology can significantly reduce this added mass. It utilizes the piezoelectric effect of piezoelectric materials to convert the mechanical energy of structural vibrations into electrical energy, which is then stored or dissipated through an external circuit, achieving the purpose of transferring and consuming structural vibration energy. However, suppressing multiple modal frequencies of a controlled structure using piezoelectric shunt technology requires a relatively complex shunt circuit, further limiting its application in engineering practice. Summary of the Invention

[0004] This application provides a multimodal vibration suppression device and method to solve the problem that in the prior art, it is difficult to achieve multimodal frequency suppression of structural vibration by a single dynamic vibration absorber or a single piezoelectric shunt.

[0005] On one hand, embodiments of this application provide a multimodal vibration suppression device, including:

[0006] The elastic column is used to connect to the vibrating structure at its bottom.

[0007] An additional mass block is placed at the top of the elastic column. The elastic column and the additional mass block are used to suppress the lower frequencies of the multimodal vibration generated by the vibrating structure.

[0008] Piezoelectric elements are used to be installed on vibrating structures;

[0009] The piezoelectric shunt circuit is electrically connected to the piezoelectric unit. The piezoelectric unit and the piezoelectric shunt circuit are used to suppress the higher frequencies in the multimodal vibration frequencies generated by the vibrating structure.

[0010] On the other hand, embodiments of this application also provide a multimodal vibration suppression method, including:

[0011] The vibration spectrum of the vibrating structure was analyzed to determine the two modal frequencies;

[0012] Select an additional mass block that matches the lower of the two modal frequencies, place the additional mass block at the top of the elastic column, and connect the bottom of the elastic column to the vibrating structure.

[0013] The resistance value of the resistor module and the inductance value of the inductor module in the piezoelectric shunt circuit are determined based on the higher frequency of the two modal frequencies.

[0014] A piezoelectric unit is installed on the vibrating structure, and the piezoelectric unit, resistor module, and inductor module are connected in series in sequence.

[0015] The multimodal vibration suppression device and method disclosed in this application have the following advantages:

[0016] By adopting an electromechanical approach, the problems of excessive geometric size and added mass and overly complex structure caused by the dynamic vibration absorber controlling multimodal vibration are overcome. At the same time, the problem of overly redundant shunt circuits caused by piezoelectric shunt control of multimodal vibration is also avoided. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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 based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the installation state of a multimodal vibration suppression device on a vibrating structure, provided in an embodiment of this application.

[0019] Figure 2 A schematic diagram of the period setting on the vibration structure for the multimodal vibration suppression device provided in the embodiments of this application;

[0020] Figure 3 A comparison of the stimulated vibration response of the multimodal vibration suppression device provided in this application embodiment before and after installation on a homogeneous thin plate.

[0021] The reference numerals in the attached diagram are as follows: 1-Vibration structure, 2-Elastic column, 3-Piezoelectric unit, 4-Shunting circuit box, 41-Resistor module, 42-Inductor module, 5-Additional mass block, 51-Mounting rod. Detailed Implementation

[0022] 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 skilled in the art without creative effort are within the scope of protection of this application.

[0023] Figure 1 This is a schematic diagram of a multimodal vibration suppression device provided in an embodiment of this application. This application provides a multimodal vibration suppression device, including:

[0024] The elastic column 2 has its bottom end used for connection to the vibrating structure 1;

[0025] An additional mass block 5 is placed at the top of the elastic column 2. The elastic column 2 and the additional mass block 5 are used to suppress the lower frequencies in the multimodal vibration frequencies generated by the vibrating structure 1.

[0026] Piezoelectric unit 3 is used to be installed on the vibrating structure 1;

[0027] The piezoelectric shunt circuit is electrically connected to the piezoelectric unit 3. The piezoelectric unit 3 and the piezoelectric shunt circuit are used to suppress the higher frequencies in the multimodal vibration frequencies generated by the vibrating structure 1.

[0028] For example, the elastic column 2 can be made of one or a combination of viscoelastic materials such as rubber, foam plastic, and sponge. The elastic column 2 and the piezoelectric unit 3 can be directly attached to the surface of the vibrating structure 1, specifically using adhesive or epoxy resin for bonding.

[0029] In the embodiments of this application, the elastic column 2 and the piezoelectric unit 3 need to be placed in the same area on the surface of the vibration structure 1, and the area should be relatively small, that is, the distance between the elastic column 2 and the piezoelectric unit 3 should be relatively small, so that the multimodal frequency vibrations at two positions of the vibration structure 1 that are very close to each other can be suppressed.

[0030] After determining the multimodal frequencies of the vibrating structure 1, the index values ​​of the electronic components in the corresponding piezoelectric shunt circuit can be determined based on the higher frequencies among the multimodal frequencies. Then, by connecting the electronic components and piezoelectric units in series with the index values, a complete piezoelectric shunt circuit loop can be formed. When using piezoelectric shunt vibration suppression technology, the mechanical energy of the vibrating structure 1 is converted into electrical energy through the piezoelectric effect of the piezoelectric unit 3. This electrical energy is then dissipated as heat through the piezoelectric shunt circuit, thus consuming vibration energy and suppressing vibration.

[0031] In one possible embodiment, the piezoelectric shunt circuit is disposed in the shunt circuit box 4.

[0032] For example, the piezoelectric shunt circuit can be mounted on a PCB board, which can be installed in the shunt circuit box 4 using screws or slots. Furthermore, the shunt circuit box 4 can be made of plastic, and its bottom surface needs to have two through holes for the wires led out from the piezoelectric unit 3 to pass through.

[0033] In the embodiments of this application, the shunt circuit box 4 can be disposed at the top of the elastic column 2, and the additional mass block 5 can be disposed on the top surface of the shunt circuit box 4. Since both the shunt circuit box 4 and the additional mass block 5 are disposed at the top of the elastic column 2, the shunt circuit box 4 and its internal PCB circuit board can also be considered as part of the mechanical dynamic vibration absorber, forming the mass part of the dynamic vibration absorber together with the additional mass block 5, which can reduce the volume and mass of the additional mass block 5. At the same time, the elastic column 2 and the shunt circuit box 4 can be connected together by adhesive, specifically by using glue or epoxy resin.

[0034] In one possible embodiment, the additional mass block 5 is mounted on the top surface of the shunt circuit box 4 via a mounting rod 51.

[0035] For example, the mounting rod 51 can be a screw or a smooth rod. When a screw is used, the additional mass block 5 is provided with a screw hole that matches the screw, and the additional mass block 5 is screwed onto the mounting rod 51.

[0036] Regardless of whether the mounting rod 51 is a screw or a smooth rod, a screw hole needs to be provided on the top surface of the shunt circuit box 4, and a thread matching the screw hole needs to be provided on the bottom side of the mounting rod 51, so that the mounting rod 51 can be connected to the shunt circuit box 4 by screwing. Using a screw connection can improve the ease of installation and removal of the mounting rod 51, and using the mounting rod 51 to connect the additional mass block 5 also facilitates the quick replacement of additional mass blocks 5 with different masses, so as to achieve the purpose of matching the modal frequency of the additional mass with the vibration structure 1.

[0037] In one possible embodiment, the piezoelectric shunt circuit includes a resistor module 41 and an inductor module 42 connected in series.

[0038] For example, the inductor module 42 is an artificially simulated inductor, which includes a capacitor, a resistor and a bipolar operational amplifier connected in series. This simulation method can obtain an equivalent inductance with a larger inductance value to solve the problem of excessive inductance value required by the piezoelectric shunt circuit when controlling low-frequency vibration.

[0039] The following example uses a piezoelectric shunt circuit composed of resistor module 41 and inductor module 42 connected in series to illustrate the principle of suppressing the vibration of vibration structure 1 by adjusting the parameters of the shunt circuit.

[0040] The positive and negative terminals of piezoelectric unit 3 are connected to a piezoelectric shunt circuit to form a loop. The resonant frequency of this circuit is... In the formula: L eq C represents the inductance value of inductor module 42. p The capacitance value is for piezoelectric unit 3. The electromechanical coupling coefficient is obtained by opening and short-circuiting the piezoelectric shunt circuit in shunt circuit box 4. In the formula: ω K and ω S These are the mode frequencies when the piezoelectric shunt circuit is open-circuited and short-circuited, respectively. The optimal resistance value for resistor module 41 is... The optimal inductance value of inductor module 42 is In the formula: ω0 is the mode frequency that the piezoelectric shunt circuit needs to suppress.

[0041] Furthermore, to ensure that the resistance value of resistor module 41 and the inductance value of inductor module 42 reach the aforementioned optimal values, both resistor and resistor module 41 employ adjustable potentiometers. By adjusting the knob of the adjustable potentiometer, its resistance value can be changed accordingly, thereby ensuring that the resistance values ​​of resistor module 41 and resistor meet the requirements, achieving the effect of piezoelectric shunt circuit and mode frequency matching.

[0042] This application also provides a multimodal vibration suppression method, which includes the following steps:

[0043] The vibration spectrum of vibrating structure 1 is analyzed to determine the two modal frequencies;

[0044] Select an additional mass block 5 that matches the lower of the two modal frequencies, place the additional mass block 5 at the top of the elastic column 2, and connect the bottom of the elastic column 2 to the vibration structure 1.

[0045] The resistance value of resistor module 41 and the inductance value of inductor module 42 in the piezoelectric shunt circuit are determined based on the higher frequency of the two modal frequencies.

[0046] A piezoelectric unit 3 is set on the vibration structure 1, and the piezoelectric unit 3, the resistor module 41, and the inductor module 42 are connected in series.

[0047] Furthermore, the additional mass block 5, elastic column 2, piezoelectric unit 3 and piezoelectric shunt circuit constitute a multimodal vibration suppression device, and multiple multimodal vibration suppression devices are installed on the vibration structure 1 according to a set period.

[0048] like Figure 2 As shown, by setting the multimodal vibration suppression device according to a specific period, the periodic structure exhibits bandgap filtering characteristics. That is, vibration waves outside the bandgap frequency range can propagate normally, while vibration waves within the bandgap frequency range cannot propagate freely and are significantly suppressed. This application further enhances the vibration suppression performance by periodically placing the multimodal vibration suppression device on the vibrating structure 1, generating multiple modal bandgap modes, and achieving broadband vibration suppression.

[0049] Figure 3 The figure shows the vibration response before and after installing the multimodal vibration suppression device of this application on a homogeneous thin plate. As can be seen from the figure, the vibration is significantly suppressed when the multimodal vibration suppression device of this application is used.

[0050] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0051] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A multi-modal vibration suppression device, characterized by, The application relates to a multi-modal vibration suppression device. The application comprises: a resilient column (2) with a bottom end for direct connection with a vibrating structure (1); an additional mass block (5) arranged at the top end of the resilient column (2), the resilient column (2) and the additional mass block (5) being used for suppressing lower frequencies in multi-modal vibration frequencies generated by the vibrating structure (1); a piezoelectric unit (3) arranged on the vibrating structure (1); a piezoelectric shunt circuit electrically connected with the piezoelectric unit (3), the piezoelectric unit (3) and the piezoelectric shunt circuit being used for suppressing higher frequencies in multi-modal vibration frequencies generated by the vibrating structure (1); the piezoelectric shunt circuit is arranged in a shunt circuit box (4); the piezoelectric shunt circuit comprises a resistance module (41) and an inductance module (42) connected in series; the inductance module (42) comprises a capacitor, a resistance and a dual-pole operational amplifier connected in series; 2. The multi-modal vibration suppression device of claim 1, wherein, the resistance and the resistance module (41) are both adjustable potentiometers.

3. The multi-modal vibration suppression device of claim 2, wherein, The shunt circuit box (4) is arranged at the top end of the resilient column (2), and the additional mass block (5) is arranged on the top surface of the shunt circuit box (4).

4. The multi-modal vibration suppression device of claim 3, wherein, The additional mass block (5) is arranged on the top surface of the shunt circuit box (4) through a mounting rod (51).

5. A multi-modal vibration suppression method using the multi-modal vibration suppression device according to any one of claims 1 to 4, characterized by, The mounting rod (51) is a screw rod, and the additional mass block (5) is provided with a screw hole matched with the screw rod, and the additional mass block (5) is screwed on the mounting rod (51). The application comprises: analyzing the vibration frequency spectrum of the vibrating structure (1) to determine two modal frequencies; selecting an additional mass block (5) matched with the lower frequency of the two modal frequencies, arranging the additional mass block (5) at the top end of the resilient column (2), and directly connecting the bottom end of the resilient column (2) with the vibrating structure (1); determining the resistance value of the resistance module (41) and the inductance value of the inductance module (42) in the piezoelectric shunt circuit according to the higher frequency of the two modal frequencies; 6. The multi-modal vibration mitigation method of claim 5, wherein, arranging the piezoelectric unit (3) on the vibrating structure (1), and sequentially connecting the piezoelectric unit (3), the resistance module (41) and the inductance module (42) in series. The additional mass block (5), the resilient column (2), the piezoelectric unit (3) and the piezoelectric shunt circuit form a multi-modal vibration suppression device, and multiple multi-modal vibration suppression devices are arranged on the vibrating structure (1) according to a set period.

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