A star-shaped particle damping mechanical metamaterial vibration isolation device

Abstract

The present invention discloses a star-shaped particle damping mechanical metamaterial vibration isolation device, comprising a protective shell, a vibration transmission device, a self-lubricating plate, and an internal vibration damping device: the protective shell is composed of an upper and lower protective shells; the vibration transmission device is provided with two, which are arranged on both sides of the protective shell, including a bearing plate, a force transmission plate, a sliding rod and a compression spring; the sliding rod passes through the through hole of the protective shell and is respectively connected to the force transmission plate and the internal vibration damping device at both ends; there are two self-lubricating plates, which are respectively fixed to the inner surfaces of the upper and lower protective shells; the vibration damping device is composed of a vibration damping external frame, a cross clamp, a four-pointed star clamp and a spherical particle damper, and the vibration damping external frame includes a vibration damping baffle, an arc-shaped clamp and a right-angle clamp; the cross clamp includes a cross frame and a right-angle clamp, and the cross clamp and the four-pointed star clamp are periodically arranged on the inner side of the vibration damping external frame, and the spherical particle damper is arranged between the vibration damping external frame, the self-lubricating plate, the cross clamp and the four-pointed star clamp and is clamped by the arc-shaped and right-angle clamps.

Description

Technical Field

[0001] The present invention relates to the technical field of artificial elastic wave metamaterials, and in particular to a particle damping discrete particle elastic wave metamaterial vibration isolation device with multi-directional synergistic effects. Background Art

[0002] Mechanical metamaterials are artificial composite structures with periodic properties. In recent years, they have gained widespread application in engineering due to their strength and lightweight properties. By tailoring the structural parameters of mechanical metamaterials to their band gap range within the frequency range of the vibration source, vibrations are prevented from propagating within the metamaterial, thereby achieving vibration isolation and noise reduction. Researchers worldwide have conducted extensive research on the band gap properties of mechanical metamaterials, applying them to vibration control technologies in rockets, ships, and aircraft.

[0003] Compared to traditional structures, star-shaped superstructures exhibit a "tensile" effect—expanding when subjected to tension and contracting when subjected to compression. This gives them greater shear strength and indentation resistance, as well as superior vibration and impact energy dissipation capabilities. Furthermore, through optimized design, star-shaped structures can be rationally expanded to various geometric shapes, such as plates and shells, to accommodate diverse operating conditions, and are widely used in vibration isolation and noise reduction projects.

[0004] Vibration isolation through damping is the best way to suppress structural resonance and reduce structure-borne noise. Particle dampers, for example, achieve this by filling the structural cavity with particles. When the structure vibrates, the particles collide and rub against each other, dissipating some of the vibration energy. Particle dampers offer a wide operating frequency band, excellent vibration reduction, and a wide range of applications, making them widely used in aerospace and mechanical vibration control.

[0005] The demand for vibration control in the current engineering field is growing. Traditional vibration isolation technologies primarily rely on elastic materials, dampers, or resonant absorbers. However, these technical solutions have many limitations. For example, while elastic material isolators have a simple structure, their ability to absorb high-frequency vibrations is limited, making it difficult to provide effective vibration reduction across a wide frequency range. Traditional dampers rely on viscoelastic materials or fluids to dissipate vibration energy, which is easily affected by changes in ambient temperature, resulting in unstable damping performance. While resonant absorbers can provide good vibration reduction at specific frequencies, they have a narrow tuning range and are less adaptable to conditions with large frequency variations.

[0006] Furthermore, existing vibration isolation devices often suffer from high structural stiffness and limited energy absorption capacity, making them ineffective against sudden impact loads. While some periodic metamaterial vibration isolation devices possess band gap properties that can suppress elastic wave propagation within a specific frequency range, their vibration reduction effectiveness in the low-frequency range remains limited. Furthermore, existing particle dampers are limited by the random distribution of particles, making their energy absorption capacity difficult to predict and optimize, and their application in vibration isolation devices can be unstable. Summary of the Invention

[0007] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a star-shaped particle damping mechanical metamaterial vibration isolation device. The device achieves vibration isolation in a low-frequency, wide-bandgap range by utilizing the bandgap characteristics of the mechanical metamaterial, the energy absorption characteristics of the star-shaped structure, and the energy dissipation characteristics of the particle damping, and can meet the vibration reduction and noise reduction problems under higher support strength.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A star-shaped particle damping mechanical metamaterial vibration isolation device includes a protective shell, a vibration transmission device, a self-lubricating plate, and an internal vibration reduction device. The protective shell is a square prismatic shell, including an upper protective shell and a lower protective shell. The upper and lower protective shells are each provided with connection holes at their four corners and are connected by bolts. The lower protective shell is provided with a plurality of circular through holes along the side edges of the square.

[0010] The vibration transmission device is provided with two, and is arranged on both sides of the protective shell, including a load-bearing plate, a force transmission plate, a sliding rod and a compression spring. The load-bearing plate and the force transmission plate are provided with a plurality of through holes, and the external vibration source and the load-bearing plate, as well as the load-bearing plate and the force transmission plate are connected by bolts; both ends of the sliding rod are provided with threads, one end passes through the through hole of the protective shell and is connected to the force transmission plate through a nut and a gasket, and the other end is connected to the internal vibration damping device through a thread; the compression spring is installed on the sliding rod, one end contacts the inner wall of the protective shell, and the other end contacts the internal vibration damping device;

[0011] There are two self-lubricating plates, which are fixed to the inner surfaces of the upper and lower protective outer shells respectively to reduce friction;

[0012] The internal vibration damping device consists of a vibration damping external frame, a cross block, a four-pointed star block and a spherical particle damper. The vibration damping external frame includes a vibration damping baffle, an arc-shaped compressor and a right-angle compressor. Several threaded holes are provided on the four sides of the vibration damping external frame. In the vibration transmission direction of the vibration transmission device, the sliding rod passes through the threaded holes and is connected to the arc-shaped compressor, and the threaded holes on the other two sides of the vibration damping external frame are connected to the arc-shaped compressor by bolts; the cross block includes a cross frame and a right-angle compressor, and the cross frame and the right-angle compressor are connected by bolts; the cross block and the four-pointed star block are periodically arranged on the inner side of the vibration damping external frame, and the spherical particle damper is arranged in the space formed by the vibration damping external frame, the self-lubricating plate, the cross block and the star block and is compressed by the arc-shaped and right-angle compressors.

[0013] Furthermore, the compression spring is longer than the distance between the side of the lower protective shell and the internal vibration damping device, so that the compression spring is in a compressed state, providing a buffer for the protective shell and the internal vibration damping device.

[0014] Furthermore, the polished rod portion of the sliding rod passes through the through hole of the protective shell, and the interior of the through hole is coated with a self-lubricating material to reduce wear of the sliding rod.

[0015] Furthermore, the cross blocks and the four-pointed star blocks in the internal vibration reduction device are arranged alternately and periodically, and have Bragg scattering band gap characteristics. Vibrations decay rapidly in the band gap and cannot propagate. However, within the frequency range where waves and vibrations can pass, due to the presence of the spherical particle damping and the overall star-shaped structure, vibration energy is dissipated to achieve vibration reduction.

[0016] Furthermore, the arc-shaped pressing device and the right-angle pressing device squeeze the spherical particle damper through the stud bolt or the flat-end set screw so that the spherical particle damper is closely arranged in the internal vibration damping device.

[0017] Furthermore, the protective shell is made of acrylic and is stably placed on a horizontal platform, and the vibration transmission device, self-lubricating plate, and internal vibration damping device are all kept parallel to the horizontal planes of the upper protective shell and the lower protective shell.

[0018] Furthermore, the bearing surface of the bearing plate is higher than the upper end surface of the screw, so that the bearing plate can be in close contact with the vibration source, and the lower protective outer shell connection hole is a countersunk hole, which is used to make the screw end surface located inside the lower protective outer shell to ensure the flatness of the installation plane.

[0019] Furthermore, the through holes on the bearing plate are coaxial with some through holes on the force transmission plate and are used for connecting to an external vibration source.

[0020] Furthermore, the internal vibration reduction device has the best vibration reduction effect when the external excitation frequency is within the range of 20 to 170 Hz, 180 to 430 Hz, and above 450 Hz.

[0021] Furthermore, the internal vibration damping device has a negative Poisson's ratio characteristic and has the ability to resist impact loads; the axis of the sliding rod is maintained on a horizontal plane.

[0022] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0023] 1. Wideband vibration isolation effect: With a periodic structure and bandgap effect, the cross-shaped and star-shaped blocks in the internal vibration reduction device are arranged alternately and periodically, forming a clear bandgap based on the Bragg scattering principle, effectively blocking the propagation of elastic waves in the frequency bands of 20-170Hz, 180-430Hz, and above 450Hz. Through particle damping to dissipate energy, outside the bandgap, the spherical particle damping converts the remaining vibration energy into heat energy through collision and friction between particles, with the blocks, and with the outer frame, further expanding the vibration isolation frequency band.

[0024] 2. Excellent energy absorption and impact resistance: The star-shaped structure with a negative Poisson's ratio exhibits "tensile expansion" characteristics under vibration and impact loads, rapidly absorbing and dissipating energy, enhancing the overall system's impact resistance and energy dissipation capabilities. It also exhibits multi-directional synergy, with its internal components working in different directions to achieve multiple absorption and attenuation of vibration energy, ensuring stable vibration isolation even under complex operating conditions.

[0025] 3. Improved structural safety and stability: A flexible connection design utilizes a compression spring to flexibly connect the protective housing and internal vibration damping device. This effectively cushions impacts and prevents damage from collisions. The sliding rod also defines the compression spring's deformation path, ensuring the internal structure remains stable during operation and maintaining optimal vibration isolation performance. The optimized clamping mechanism utilizes a bidirectional extrusion scheme for both the arc-shaped and right-angled clamps, allowing the spherical particle damping to be tightly packed internally. This ensures full contact between the particles, the block, and the outer frame, thereby enhancing both squeezing and energy dissipation.

[0026] 4. Ease of manufacturing and cost advantages: Most components utilize national standards, resulting in mature processing technology, high reliability, and low manufacturing costs. Furthermore, due to its purely mechanical design, it is free of electromagnetic interference and suitable for a wide range of applications. The internal vibration damping device can be flexibly adapted to different operating conditions by adjusting the number of blocks and particle loading, making the vibration isolation device widely applicable and promising for engineering applications.

[0027] 5. The device of the present invention uses a vibration transmission device to divide the elastic waves generated by the vibration source into multiple paths and evenly distribute them to the internal vibration reduction device through sliding rods. This process realizes the transformation from a single-point vibration source to a multi-point vibration source. While making full use of the internal vibration reduction device to dissipate the elastic wave energy, it also avoids damage to the single sliding rod caused by excessive load.

[0028] 6. The screw head that compresses the right-angle clamp is ground flat to increase the contact area with the right-angle clamp, avoid relative displacement during vibration, and maintain stability. In addition, a groove is set on the pressure side of the right-angle clamp to facilitate the pushing position of the flat-end set screw to be located near the middle surface to ensure the pushing effect.

[0029] 7. In the present invention, the through holes of the lower protective shell are coated with self-lubricating material to reduce friction, and the surfaces of the spherical particle damper, the arc-shaped compressor, the right-angle compressor, the star-shaped clamp, the cross clamp, and the contact surfaces of the external frame of the vibration reduction and the spherical particle damper are all sandblasted to increase the roughness of the contact surface and improve the energy consumption performance of the spherical particle damper.

[0030] 8. In the present invention, the star-shaped clamping block and the cross clamping block are non-rigidly fixed in the vibration reduction device, and a clamping block of appropriate size can be selected according to actual working conditions, which has the advantage of flexible use. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of a vibration isolation device provided in an embodiment of the present invention.

[0032] Figure 2 A schematic diagram of the explosion structure of the vibration isolation device provided in an embodiment of the present invention.

[0033] Figure 3 A schematic diagram of the explosion structure of the protective shell provided in an embodiment of the present invention.

[0034] Figure 4 Schematic diagram of the exploded structure of the bearing plate and the force transmission plate provided in an embodiment of the present invention.

[0035] Figure 5 Schematic diagram of the explosion structure of the vibration transmission device and the internal vibration reduction device provided in an embodiment of the present invention.

[0036] Figure 6 A perspective structural diagram of a vibration transmission device and an internal vibration damping device provided in an embodiment of the present invention.

[0037] Figure 7 This is a schematic diagram of the top view of the internal structure of the vibration isolation device provided by an embodiment of the present invention.

[0038] Figure 8 A schematic diagram of the explosion structure of the internal vibration reduction device provided in an embodiment of the present invention.

[0039] Figure 9 A schematic diagram of the exploded structure of a cross clamping block provided in an embodiment of the present invention.

[0040] Figure 10 Schematic diagram of the exploded structure of the compactor and the external vibration damping frame provided in an embodiment of the present invention.

[0041] Figure 11 A schematic perspective structural diagram of a right-angle presser and an external vibration damping frame provided in an embodiment of the present invention.

[0042] Figure 12 FIG. 4 is a logarithmic input response amplitude ratio curve diagram according to an embodiment of the present invention.

[0043] Figure markings: 1-vibration transmission device, 2-internal vibration damping device, 3-protective shell, 4-self-lubricating plate, 10-bearing plate, 11-force transmission plate, 12-hexagonal nut, 13-cylinder head screw, 14-hexagonal extended nut, 15-spring washer, 16-flat washer, 17-compression spring, 18-sliding rod, 20-cross block, 21-spherical particle damping, 22-four-pointed star block, 23-external vibration damping frame, 30-upper protective shell, 31-lower protective shell, 32-shell fastening screw, 200-flat end fastening screw, 201-right angle clamp, 202-cross frame, 230-arc clamp, 231-right angle clamp, 232-flat end fastening screw, 233-vibration damping baffle. DETAILED DESCRIPTION

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0045] A star-shaped particle damping mechanical metamaterial vibration isolation device employs the following scheme: a support plate is connected to the device requiring vibration damping via a through-hole in the support plate. Elastic waves generated by the vibration source are evenly transmitted to the internal vibration damping device through the support plate, divided into multiple paths by a force transmission plate, and then attenuated in three ways. First, the periodic arrangement of the internal vibration damping device's internal blocks and spherical particle damping reduces the propagation of elastic waves within the band gap due to the Bragg scattering mechanism, thereby achieving a vibration damping effect. Second, the internal vibration isolation device's star-shaped structure, due to its overall "tensile expansion" properties, further absorbs elastic wave energy. Finally, each internal vibration device is filled with spherical particle dampers. Elastic wave energy is dissipated through collision and friction between the spherical particle dampers, between the spherical particles and the blocks, and between the spherical particles and the outer frame. The energy absorption of the star-shaped structure and the energy dissipation of the particle damping enable the internal vibration damping device to attenuate elastic waves within the frequency range where fluctuations and vibrations can pass, thereby expanding the vibration isolation frequency range. The attenuated elastic wave is transmitted from the vibration transmission device on the opposite side.

[0046] like Figures 1 to 3 As shown, a star-shaped particle damping mechanical metamaterial vibration isolation device according to an embodiment of the present invention comprises: a vibration transmission device 1, an internal vibration damping device 2, a protective housing 3, and a self-lubricating plate 4. The protective housing 3 is stably placed on a horizontal platform. The vibration transmission device 1, the internal vibration damping device 2, and the self-lubricating plate 4 are all parallel to the protective housing 3. The upper and lower surfaces of the internal vibration damping device 2 are in contact with the self-lubricating plate 4. The protective housing 3 consists of an upper protective shell 30 and a lower protective shell 31, connected by shell fastening screws 32. The lower protective shell 31 has a plurality of through-holes evenly spaced along the sides of the square. The upper and lower protective shells 30 and 31 are connected by shell fastening screws 32. The lower protective shell 31 has countersunk holes so that the end faces of the shell fastening screws 32 are located inside the lower protective shell 31, maintaining a flat installation surface. The self-lubricating plate 4 is treated with naphthalene and then fixed to the upper and lower protective shells 30 and 31 using epoxy resin adhesive. In this embodiment of the present invention, the upper and lower protective shells 30 and 31 are made of acrylic, while the self-lubricating plate 4 is made of polytetrafluoroethylene. Because polytetrafluoroethylene has a low coefficient of friction and excellent wear resistance, it not only reduces the impact of the upper and lower boundaries on the internal vibration damping device 2, but also provides protection and extends the device's service life.

[0047] like Figure 4The figure shows the connection structure between the bearing plate and the force transmission plate. The bearing plate 10 and the force transmission plate 11 are connected by two cylindrical head screws 13, two hexagonal extended nuts 14, two spring washers 15, four flat washers 16 and two hexagonal nuts 12. The hexagonal extended nuts are used to extend the distance between the bearing plate 10 and the force transmission plate 11 to prevent the bearing plate 10 from colliding with the sliding rod 18 between the two plates. Some through holes of the bearing plate 10 and the force transmission plate 11 are coaxial and are used to connect the external vibration source and the vibration transmission device. In the embodiment of the present invention, the bearing plate 10 and the force transmission plate 11 are both made of ABS (acrylonitrile-butadiene-styrene copolymer); the cylindrical head screws 13, the hexagonal extended nuts 14, the flat washers 16 and the sliding rod 18 are made of stainless steel; and the spring washers 15 are made of spring steel.

[0048] like Figure 5 and Figure 6 The figure shows the connection structure between the force transmission rod and the internal vibration damping frame. One end of the sliding rod 18 is connected to the force transmission rod 11 through two hexagonal nuts 12, a spring washer 15 and two flat washers 16, and the other end is connected to the external vibration damping frame 23 through a threaded hole. The top end presses the bottom of the blind hole of the arc-shaped compressor 230. The middle part of the sliding rod is a smooth rod, which passes through the through hole of the lower protective shell 31. The inside of the through hole is coated with self-lubricating material to reduce wear. The lower protective shell 31 and the external vibration damping frame 23 are flexibly connected by a compression spring 17 to prevent the vibration damping internal frame 23 from excessive displacement and collision with the lower protective shell 31 during use. The compression spring 17 is coaxial with the sliding rod 18 and is always in a compressed state. Its moving trajectory is constrained by the sliding rod and moves in the axial direction. In the embodiment of the present invention, the compression spring 17 is made of stainless steel; the arc-shaped compressor 230 is made of ABS.

[0049] like Figure 7 and Figure 8 The diagram shows the structure of the internal vibration damping device. The internal vibration damping device 2 consists of a cross-shaped block 20, spherical particle dampers 21, star-shaped blocks 22, and an external vibration damping frame 23. The cross-shaped blocks 20 and star-shaped blocks 22 are periodically arranged within the external vibration damping frame 23, giving the structure a bandgap characteristic. The spherical particle dampers 21 are closely arranged and fill the gaps between the cross-shaped block 20, star-shaped block 22, external vibration damping frame 23, and self-lubricating plate 4, giving the overall structure a "auxetic" characteristic. In this embodiment of the present invention, the spherical particle dampers 21 are made of stainless steel, and the star-shaped blocks 22 are made of ABS.

[0050] like Figure 9The cross block structure is shown. The cross block 20 consists of eight flat-ended set screws 200, four right-angled clamps 201, and a cross frame 202. The four internal right-angled sides of the cross block 20 are each connected to two orthogonal flat-ended set screws 200 through threaded holes. The four right-angled clamps 201 compress the spherical particle damper 21 in four directions by adjusting each flat-ended set screw 200. In this embodiment of the present invention, the flat-ended set screws 200 are made of stainless steel; the right-angled clamps 201 and cross frame 202 are made of ABS.

[0051] like Figure 10 and Figure 11 The figure shows the external vibration damping frame structure. The vibration damping external frame 23 consists of an arc-shaped clamp 230, a right-angle clamp 231, a flat-end set screw 232, and a vibration damping baffle 233. The flat-end set screw 232 passes through the threaded hole on the side of the vibration damping baffle 233 to push the arc-shaped clamp 230 and the right-angle clamp 231 together. The right-angle clamp 231 can compress the spherical particle damper 21 by adjusting the two orthogonal flat-end set screws 232. The arc-shaped clamp 230 pushes the spherical particle damper 21 along the axis of its countersunk hole. This ensures that the relative positions of the cross block 20, spherical particle damper 21, and star block 22 do not change during use, thereby ensuring the effectiveness of the "tension" and band gap characteristics. The curved surface of the arc-shaped pressing device 230 and the right-angled vertical surface of the right-angle pressing device 231 are consistent with the contact surface of the corresponding squeezed spherical particle damper 21, thereby improving the pushing effect. In this embodiment of the present invention, the right-angle pressing device 231 is made of ABS material; the flat-end set screw 232 is made of stainless steel.

[0052] The working principle of the star-shaped particle damping mechanical metamaterial vibration isolation device of the above-mentioned invention embodiment includes:

[0053] The star-shaped structure exhibits a negative Poisson's ratio and exhibits "tensile" properties, meaning it expands laterally when subjected to tension and contracts laterally when subjected to compression. This structure also provides excellent shock and vibration dissipation capabilities. When the vibration damper is subjected to vibration or impact, the spherical particle dampers and retaining blocks converge toward the outer frame, increasing the local stiffness near the outer frame and enhancing the device's energy absorption and protection capabilities.

[0054] Cross and star blocks are periodically staggered within the internal vibration damping device, creating periodic zones. This gives the device a bandgap characteristic. Within the bandgap frequency range, elastic waves are affected by the interaction of internal components, reducing their propagation performance, resulting in a vibration-damping effect. The present invention primarily utilizes the Bragg bandgap to dampen waves within its frequency range. According to the Bragg scattering mechanism, the location of the bandgap must meet the following requirements:

[0055]

[0056] Where a is the lattice size of the metamaterial; λ is the wavelength of the elastic wave in the metamaterial.

[0057] For elastic waves outside the band gap frequency range, in addition to the energy absorption and vibration reduction of the negative Poisson's ratio structure, the friction and collision between the spherical particle damping, the block, and the external vibration reduction frame are used to convert part of the input elastic wave energy into heat energy for dissipation, thereby achieving a vibration reduction effect.

[0058] The embodiment of the present invention provides the simulation results of elastic wave input and response amplitude logarithmic ratio of the vibration isolation device at 0-1800Hz. Figure 12 As shown, the vibration reduction device has significant vibration reduction effects at frequencies between 20 and 170 Hz, 180 and 430 Hz, and above 450 Hz. Simulation results show that by combining the bandgap characteristics of the periodic structure, the "tensile expansion" properties of the negative Poisson's ratio material, and the dissipative effect of particle damping, the embodiments of the present invention can effectively achieve vibration and noise reduction across a wide low-frequency range.

[0059] In summary, compared to conventional periodic vibration isolation devices, the device of the present invention's embodiment excels by combining the energy absorption characteristics of a negative Poisson's ratio structure, the band gap characteristics of a mechanical metamaterial, and the dissipative characteristics of a particle damper, resulting in significant vibration reduction across a wide low-frequency range. Furthermore, because the internal vibration reduction device as a whole utilizes a negative Poisson's ratio structure, the device also possesses a certain degree of shock resistance. This device provides an easy-to-manufacture, electromagnetically interference-free, and shock-resistant nonlinear vibration isolation and noise reduction device for operating conditions involving elastic waves and vibrations of multiple frequencies.

[0060] Those skilled in the art will appreciate that, unless expressly stated otherwise, the singular forms "a", "an", "" and "the" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, "connected" or "coupled" as used herein may include wireless connections or couplings. The term "and / or" as used herein includes any unit and all combinations of one or more of the associated listed items.

[0061] The present invention is not limited to the embodiments described above. The above description of the specific embodiments is intended to describe and illustrate the technical solutions of the present invention. The above specific embodiments are merely illustrative and not restrictive. Without departing from the scope of the present invention and the scope of protection of the claims, those skilled in the art may make various specific modifications based on the teachings of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A star-shaped particle damping mechanical metamaterial vibration isolation device, characterized in that: It includes a protective shell, a vibration transmission device, a self-lubricating plate, and an internal vibration damping device: the protective shell is a square prismatic shell, including an upper protective shell and a lower protective shell, the four corners of the upper protective shell and the lower protective shell are provided with connection holes and are connected by bolts, and the lower protective shell is provided with a plurality of circular through holes along the side of the square; The vibration transmission device is provided with two, and is arranged on both sides of the protective shell, including a load-bearing plate, a force transmission plate, a sliding rod and a compression spring. The load-bearing plate and the force transmission plate are provided with a plurality of through holes, and the external vibration source and the load-bearing plate, as well as the load-bearing plate and the force transmission plate are connected by bolts; both ends of the sliding rod are provided with threads, one end passes through the through hole of the protective shell and is connected to the force transmission plate through a nut and a gasket, and the other end is connected to the internal vibration damping device through a thread; the compression spring is installed on the sliding rod, one end contacts the inner wall of the protective shell, and the other end contacts the internal vibration damping device; There are two self-lubricating plates, which are fixed to the inner surfaces of the upper and lower protective outer shells respectively to reduce friction; The internal vibration damping device is composed of a vibration damping external frame, a cross clamp, a four-pointed star clamp and a spherical particle damper. The vibration damping external frame includes a vibration damping baffle, an arc-shaped clamp and a right-angle clamp. A number of threaded holes are provided on the four sides of the vibration damping external frame. In the vibration transmission direction of the vibration transmission device, the sliding rod passes through the threaded holes and is connected to the arc-shaped clamp, and the threaded holes on the other two sides of the vibration damping external frame are connected to the arc-shaped clamp by bolts; the cross clamp includes a cross frame and a right-angle clamp, and the cross frame and the right-angle clamp are connected by bolts; the cross clamp and the four-pointed star clamp are periodically arranged on the inner side of the vibration damping external frame, and the spherical particle damper is arranged in the space formed by the vibration damping external frame, the self-lubricating plate, the cross clamp and the star clamp and is compressed by the arc-shaped and right-angle clamps; The cross blocks and the four-pointed star blocks in the internal vibration damping device are arranged alternately and periodically, and have the characteristics of a Bragg scattering band gap. Vibrations decay rapidly in the band gap and cannot propagate. However, within the frequency range where waves and vibrations can pass, due to the presence of the spherical particle damping and the overall star-shaped structure, vibration energy is dissipated to achieve vibration reduction.

2. The star-shaped particle damping mechanical metamaterial vibration isolation device according to claim 1, characterized in that: The compression spring is longer than the distance between the side of the lower protective shell and the internal vibration damping device, so that the compression spring is in a compressed state, providing a buffer for the protective shell and the internal vibration damping device.

3. The star-shaped particle damping mechanical metamaterial vibration isolation device according to claim 1, characterized in that: The polished rod portion of the sliding rod passes through the through hole of the protective shell, and the interior of the through hole is coated with a self-lubricating material to reduce wear of the sliding rod.

4. The star-shaped particle damping mechanical metamaterial vibration isolation device according to claim 1, characterized in that: The arc-shaped pressing device and the right-angle pressing device squeeze the spherical particle damper through the stud bolt or the flat-end set screw so that the spherical particle damper is closely arranged in the internal vibration damping device.

5. The star-shaped particle damping mechanical metamaterial vibration isolation device according to claim 1, characterized in that: The protective shell is made of acrylic and is stably placed on a horizontal platform. The vibration transmission device, self-lubricating plate, and internal vibration reduction device are all kept parallel to the horizontal planes of the upper protective shell and the lower protective shell.

6. The star-shaped particle damping mechanical metamaterial vibration isolation device according to claim 1, characterized in that: The bearing surface of the bearing plate is higher than the upper end surface of the screw, so that the bearing plate can be in close contact with the vibration source. The connecting hole of the lower protective shell is a countersunk hole, which is used to make the end surface of the screw located on the inner side of the lower protective shell to ensure the flatness of the installation plane.

7. The star-shaped particle damping mechanical metamaterial vibration isolation device according to claim 1, characterized in that: The through holes on the bearing plate are coaxial with part of the through holes on the force transmission plate and are used for connecting to an external vibration source.

8. The star-shaped particle damping mechanical metamaterial vibration isolation device according to claim 1, characterized in that: The internal vibration reduction device has the best vibration reduction effect when the external excitation frequency is within the range of 20-170 Hz, 180-430 Hz and above 450 Hz.

9. The star-shaped particle damping mechanical metamaterial vibration isolation device according to claim 1, characterized in that: The internal vibration damping device has a negative Poisson's ratio characteristic and has the ability to resist impact loads; the axis of the sliding rod is maintained in a horizontal plane.

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