Dot-matrix sandwich plate structure with vibration reduction characteristics

Abstract

The application discloses a dot-matrix sandwich plate structure with vibration reduction characteristics, belongs to the field of vibration control, and can solve the problem of difficulty in multifunctional integrated design of structure bearing and low-frequency broadband gap vibration reduction. The dot-matrix sandwich plate structure is composed of dot-matrix sandwich cells containing local resonance microstructures and arranged periodically in two-dimensional directions; the dot-matrix sandwich cell is composed of two slotted thin panels, double-pyramid Kagome rod system dot-matrix and resonators; the realization of the resonance microstructure is that a steel cylinder is additionally arranged at the center of the elastic short beam through slotting on the panel, so that the vibration reduction frequency of the structure can be effectively reduced; the application can realize effective vibration suppression in a low-frequency band and can be used for vibration reduction facilities with bearing requirements.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vibration control, and particularly relates to a dot-matrix sandwich plate structure with a vibration reduction characteristic. BACKGROUND

[0002] Effective vibration reduction technology is an important means for inhibiting harmful vibration in the field of vibration engineering. In recent years, the emergence of local resonance type acoustic metamaterials with low-frequency elastic wave band gap characteristics provides a new technical method for vibration suppression. The local resonance type acoustic metamaterials realize special physical properties that conventional materials do not have, such as negative effective mass characteristics and negative modulus characteristics, through the design of microstructures. The microstructure is usually constructed by periodically embedding local resonance units in an elastic matrix, and the local resonance unit is composed of two structures with different material parameters or structural parameters. When the elastic wave propagates in the macrostructure formed by the periodic or non-periodic expansion of the microstructure, the wave energy in a specific frequency band is weakened due to the influence of the resonant microstructure, and a low-frequency elastic wave band gap is generated. This band gap is called a local resonance type band gap, and vibration is severely attenuated in the frequency range corresponding to the band gap. Since the generation of the band gap is dominated by the resonance characteristics of a single microstructure cell, low-frequency vibration reduction can be achieved using small-sized structures. Designing a vibration reduction structure based on local resonance type acoustic metamaterials is an effective low-frequency vibration suppression measure.

[0003] Lightweight sandwich structures are widely used in aerospace, vehicles, ships and building engineering due to their excellent static load bearing performance. Kagome dot-matrix structure is a relatively classic dot-matrix structure configuration with excellent plastic buckling resistance. Dot-matrix sandwich plate structures with Kagome dot-matrix as the core layer have the potential to become multifunctional structures. There is an increasing demand for vibration reduction function of plate-shaped structures with load bearing capacity in engineering. Due to the complex configuration of dot-matrix structures and the high precision required for the realization of metamaterial properties, it is difficult to prepare such structures, so it is difficult to design multifunctional structures with load bearing and low-frequency wide-band gap vibration reduction. SUMMARY

[0004] The application provides a dot-matrix sandwich plate structure with a vibration reduction characteristic. In addition to the characteristics of conventional sandwich structures, the sandwich plate structure can suppress elastic waves at low frequencies and wide frequency bands through periodically arranged local resonance structure units, thereby achieving high-efficiency vibration reduction performance.

[0005] To achieve the above purpose, the technical scheme adopted by the application is as follows:

[0006] A sandwich plate structure with vibration reduction characteristics is composed of a lattice sandwich unit with local resonance characteristics periodically extended in two-dimensional direction; the lattice sandwich unit comprises: an upper panel, a lower panel, a double-pyramid Kagome lattice, a protrusion and a metal cylinder; the upper panel and the lower panel are connected through the double-pyramid Kagome lattice, the double-pyramid Kagome lattice is composed of four cross circular rods; the protrusion is located at the center of the upper and lower panels and is cylindrical; the metal cylinder is connected with the protrusion and has the same radius as the protrusion;

[0007] The upper panel and the lower panel are symmetrical structures with the same structural characteristics; the upper panel and the lower panel adopt a slotted design, and 10 elastic beams are formed in a 36° circumferential array after slotting;

[0008] The height of the protrusion combined with the metal cylinder should be such that the metal cylinder maintains a certain distance from the Kagome lattice to ensure that the metal cylinder is not affected when vibrating;

[0009] The material properties of the protrusion and the panel are the same or the protrusion is made of soft materials such as rubber.

[0010] Beneficial effects: the present application provides a lattice sandwich plate structure with vibration reduction characteristics, compared with the prior art, the present application has the following effects:

[0011] 1. The lattice sandwich plate structure with vibration reduction characteristics provided by the present application comprises a local resonance unit composed of an elastic beam, a protrusion and a metal cylinder, when the structure is subjected to vibration disturbance, due to the existence of the local resonance unit, the energy of a certain frequency band input into the sandwich plate structure will be attenuated, the frequency band is the elastic wave band gap, and the vibration suppression for a certain frequency band can be realized through the design of the local resonance unit;

[0012] 2. The structure and material parameters of the elastic beam, the protrusion and the metal cylinder in the present application can change the frequency range of the band gap, and thus the vibration attenuation frequency band of the sandwich plate structure can be adjusted, realizing low-frequency and wide-frequency vibration suppression;

[0013] 3. The lattice sandwich unit in the present application is composed of two slotted thin panels, a double-pyramid Kagome rod system lattice and a resonator, and the characteristic is that the realization of the resonant microstructure is through slotting on the panel and adding a steel cylinder at the center of the elastic short beam, which can effectively reduce the vibration reduction frequency of the structure;

[0014] 4. Compared with the traditional plate structure with local resonance band gap, the present application adopts a lattice structure as the core layer, combines the local resonance type metamaterial with the Kagome lattice sandwich structure with the characteristics of light weight and high strength, has the vibration reduction characteristics, effectively improves the carrying capacity, designs a lattice sandwich superstructure with carrying and low-frequency vibration reduction characteristics, and realizes the vibration reduction of the plate-shaped structure with carrying demand in engineering. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the lattice sandwich panel with vibration reduction characteristics in an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of a lattice sandwich unit in an embodiment of the present invention;

[0017] Figure 3 This is a graph showing the relationship between transmission loss and frequency in an embodiment of the present invention.

[0018] In the figure, 1 is a slotted thin panel, 2 is an elastic beam, 3 is a protrusion, 4 is a metal cylinder, and 5 is a double pyramid Kagome lattice. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings:

[0020] like Figure 1 As shown, a lattice sandwich panel structure with vibration reduction characteristics based on acoustic metamaterials is constructed by periodically expanding lattice sandwich units with local resonance characteristics along a two-dimensional direction, as... Figure 2 As shown, the lattice sandwich unit consists of a slotted thin panel 1, an elastic beam 2, a protrusion 3, a metal cylinder 4, and a double-pyramid Kagome lattice 5; the upper and lower slotted thin panels 1 are connected by the double-pyramid Kagome lattice 5, which is composed of four intersecting round rods; the protrusion 3 is located at the center of the slotted thin panel 1 and is cylindrical; the metal cylinder 4 is connected to the protrusion 3 and has the same radius as the protrusion; the upper and lower slotted thin panels 1 are symmetrical and have the same structural features; The design employs a slotted pattern, which forms 10 elastic beams arranged in a 36° circumferential array. The height of the combination of protrusion 3 and metal cylinder 4 should ensure that the metal cylinder 4 and the double pyramid Kagome lattice 5 maintain a certain distance. The number of units, structural dimensions, and material parameters of this lattice sandwich panel structure can be adjusted according to the actual project. Increasing the number of units will result in more severe vibration attenuation. Reducing the thickness of the slotted panel, the height and diameter of the metal cylinder, or the elastic modulus of the material will lead to a decrease in the frequency of vibration attenuation, and vice versa.

[0021] The following specifies the structural dimensions and material parameters of the lattice sandwich unit: the cell panel thickness is 2mm, the side length is 40mm, the circumferential diameter of the panel slot design is 25mm, the elastic beam width is 1.5mm, the protrusion height is 4mm, the radius is 4mm, the rod radius in the Kagome rod lattice is 1.5mm, the distance from the center of the contact surface between each rod and the panel to the edge of the panel is 5mm, and the material is epoxy resin with an elastic modulus of 1.4GPa and a density of 1150Kg / m³. 3, Poisson's ratio is 0.4, the height of the metal cylindrical vibrator is 8mm, the radius is 4mm, the material is steel, the elastic modulus is 205GPa, and the density is 7850 Kg / m 3 , Poisson's ratio is 0.28.

[0022] The lattice sandwich plate structure with the vibration reduction characteristics is assembled according to the following steps:

[0023] 1. A Solidworks modeling software is used to establish the upper plate together with the protrusions, the lower plate together with the protrusions and the double-pyramid Kagome rod system lattice model;

[0024] 2. A 3D printing technology is used to prepare the above structure model;

[0025] 3. AB glue is used to bond the metal cylinder on the protrusion, and the metal cylinder is kept aligned with the protrusion;

[0026] 4. AB glue is used to bond the upper plate with the Kagome rod system lattice, and the upper plate is kept aligned with the lower plate, and the preparation of the lattice sandwich plate structure is completed.

[0027] As shown in Figure 1 , taking the overall structure composed of 6*10 cells as an example, a sweep frequency test method is used to test the vibration transmission characteristics of the structure, the test frequency range is 0-2000 Hz, and the sampling frequency interval is 10 Hz; an acceleration sensor is used to collect the acceleration response signals of the vibration input end and the output end, and a vibration transmission function is calculated, and the expression of the transmission function is; the vibration transmission curve obtained by the test is shown in Figure 3 , in the frequency range of 500Hz-970Hz (the shaded area in the figure), the vibration transmission rate has a significant decrease, which represents that the vibration is effectively attenuated in this frequency band, and the effect of using the sandwich plate structure for vibration reduction is realized, and the reason for the vibration attenuation is local resonance, the resonator composed of the metal cylinder, the protrusion and the elastic beam consumes the energy of the elastic wave propagating in the plate when it is excited by the vibration close to its natural frequency, resulting in the vibration reduction of the sandwich plate in the frequency band; the vibration transmission curve obtained by the finite element simulation calculation is shown in Figure 3 , as shown in the left figure, the vibration attenuation frequency range measured by the experiment is in good agreement with the simulation calculation result.

[0028] The above is only a preferred embodiment of the present application, which cannot limit the protection scope of the present application, and any modification made on the basis of the technical solutions according to the technical idea of the present application falls within the protection scope of the present application.

Claims

1. A sandwich panel structure with vibration damping characteristics, characterized in that, The sandwich plate structure is composed of lattice sandwich units with local resonance characteristics, which are periodically extended in two-dimensional direction; the lattice sandwich unit comprises an upper panel, a lower panel, a double-pyramid Kagome lattice, a protrusion and a metal cylinder; the upper panel and the lower panel are connected by the double-pyramid Kagome lattice, the protrusion is located at the center of the upper and lower panels; the metal cylinder is connected with the protrusion and has the same radius as the protrusion; the double-pyramid Kagome lattice is composed of four intersecting circular rods; the upper panel and the lower panel adopt a slotted design, and 10 elastic beams in a 36° circumferential array are formed after the slotted design; the elastic beams, the protrusion and the metal cylinder form a local resonance unit, and the height of the combination of the protrusion and the metal cylinder keeps the metal cylinder away from the Kagome lattice, so that the metal cylinder is not affected when vibrating.

2. The sandwich plate structure having a vibration damping property according to claim 1, characterized by, The upper panel and the lower panel are symmetrical structures.

3. The sandwich plate structure having a vibration damping property according to claim 1, characterized by, The protrusion has the same material properties as the upper and lower panels.

4. The sandwich panel structure having a vibration damping property according to claim 1, wherein The number of lattice sandwich units, the structure size and the material parameters are adjusted according to actual damping requirements.

5. The sandwich plate structure having a vibration damping property according to claim 1 or 4, characterized by By increasing the number of lattice sandwich units, the vibration attenuation is more intense, and by reducing the thickness of the upper and lower panels, the height and diameter of the metal cylinder and the elastic modulus of the material, the frequency of vibration attenuation is reduced.

6. The sandwich panel structure having a vibration damping property according to claim 5, wherein The lattice sandwich unit structure size and material parameters are as follows: the upper panel and lower panel thickness is 2mm, the side length is 40mm; the panel slot design circumferential diameter is 25mm; the elastic beam width is 1.5mm; the convex height is 4mm, and the radius is 4mm; the rod radius in the double-pyramid Kagome lattice is 1.5mm, the distance from the center of the contact surface of each rod and the panel to the panel edge is 5mm, and the materials are all epoxy resin, the elastic modulus is 1.4GPa, the density is 1150Kg / m 3 , the Poisson's ratio is 0.4, the metal cylinder height is 8mm, the radius is 4mm, the elastic modulus is 205GPa, the density is 7850 Kg / m 3 , and the Poisson's ratio is 0.28.

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