A localized resonant phonon crystal unit cell, vibration reduction structure, and installation method

Abstract

This invention discloses a locally resonant phonon crystal unit cell, a vibration reduction structure, and an installation method, belonging to the field of track vibration reduction technology. The locally resonant phonon crystal unit cell includes a silicone rubber matrix as the outer ring, with a steel scatterer disposed within the cavity of the silicone rubber matrix. The steel scatterer and the silicone rubber matrix are connected and fixed by a soft material encapsulation layer. Four spring-mass subsystems are nested within the steel scatterer. The inner cavity sidewalls of the silicone rubber matrix are also encapsulated with a soft material. Using the locally resonant phonon crystal unit cell, vibration reduction structure, and installation method described in this invention can solve the problem of poor vibration reduction effect of existing vibration reduction measures for low-frequency vibrations.

Description

[0001] Related applications

[0002] This invention claims priority to Chinese Patent Application No. 202411027899.6, filed on July 30, 2024, entitled "Local Resonance Phononic Crystal Unit Cell", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of track vibration reduction technology, and in particular to a localized resonant phononic crystal unit cell, vibration reduction structure, and installation method. Background Technology

[0004] Vibration reduction in my country's urban rail transit system is a critical issue that urgently needs to be addressed. Environmental vibrations caused by urban rail transit during operation can damage ancient buildings, affect the precision of instruments in research institutions, and impact the working environment of vibration-sensitive areas such as hospitals and libraries. Over the long term, these vibrations can also severely affect the living environment of surrounding residents and cause ground subsidence, among other problems. While current vibration reduction measures for urban rail transit are effective at reducing high-frequency vibrations, their control over low-frequency vibrations is very limited. In fact, low-frequency vibrations have a more severe impact on the aforementioned problems and are more difficult to control than high-frequency vibrations. Summary of the Invention

[0005] The purpose of this invention is to provide a localized resonant phononic crystal unit cell, a vibration reduction structure, and an installation method to solve the problem that existing vibration reduction measures have poor vibration reduction effects on low-frequency vibrations.

[0006] To achieve the above objectives, the present invention provides a localized resonant phonon crystal unit cell, comprising a silicone rubber matrix as the outer ring, a steel scatterer disposed within the cavity of the silicone rubber matrix, the steel scatterer being connected and fixed to the silicone rubber matrix by a soft material encapsulation layer; four spring mass subsystems nested within the steel scatterer; and a soft material encapsulation layer disposed on the inner cavity sidewall of the silicone rubber matrix.

[0007] Preferably, the spring mass subsystem includes a steel spring and a rubber matrix, with the helical steel spring embedded in the cylindrical rubber matrix, and the height of the steel spring being lower than that of the rubber matrix.

[0008] Preferably, the silicone rubber matrix and the spring mass subsystem are at the same height, while the height of the steel scatterer is lower than that of the silicone rubber matrix and the spring mass subsystem.

[0009] Preferably, a gap is provided between the sidewall of the steel scatterer and the silicone rubber matrix to facilitate the deformation of the silicone rubber matrix, and the height difference between the steel scatterer and the silicone rubber matrix is ​​2mm-4mm.

[0010] Preferably, the silicone rubber matrix is ​​provided with a first vibration damping hole, which is located around the silicone rubber matrix and penetrates the silicone rubber matrix. The first vibration damping hole is a spindle-shaped structure with small openings at both ends and a large opening in the middle. A plurality of second vibration damping holes are uniformly provided on the bottom surface of the silicone rubber matrix. The second vibration damping holes penetrate the bottom of the silicone rubber matrix and are conical structures with a large opening at the top and a small opening at the bottom.

[0011] A vibration damping structure includes a first vibration damping layer and a second vibration damping layer. Both the first and second vibration damping layers are composed of at least one layer of the aforementioned localized resonant phonon crystal unit cell. The first vibration damping layer is laid on the upper surface of the foundation, and the second vibration damping layer is located on both sides of the track slab. Both the first and second vibration damping layers are located between the track slab and the foundation.

[0012] Preferably, the foundation has grooves on both sides, the second damping layer is laid in the grooves, and a slider is provided between the second damping layer and the side wall of the track plate. One side of the slider is fixedly connected to the second damping layer, and the other side of the slider is provided with an inclined surface that gradually slopes from the top to the bottom towards the track plate. The slider is slidably connected to the foundation, and the track plate is slidably connected to the slider.

[0013] Preferably, the upper surface of the foundation is provided with a plurality of vibration damping components, which are distributed in a linear array on the upper surface of the foundation and are located between adjacent first vibration damping layers. Each vibration damping component includes a fixed base, which is fixedly disposed on the upper surface of the foundation. The fixed base is provided with a plurality of insertion holes evenly distributed on it. A counterweight is disposed in each insertion hole. The counterweight is slidably connected to the fixed base. A connecting piece is disposed on the top of the counterweight, and the counterweight is fixedly connected to the track plate through the connecting piece.

[0014] Preferably, the sidewall of the socket is provided with a plurality of elastic first buffer bosses that are inclined inward and downward, and the two sides of the counterweight are provided with elastic second buffer bosses that are inclined outward and upward, with the first buffer bosses and the second buffer bosses overlapping.

[0015] The installation method based on the above vibration reduction structure includes the following steps:

[0016] S1. Assemble a local resonant phonon crystal unit cell, fix a soft material wrapping layer at the four corners of the inner cavity sidewall of the silicone rubber matrix, insert a steel scatterer into the cavity, fix the steel scatterer to the soft material wrapping layer, and fix a spring mass subsystem into the mounting hole of the steel scatterer.

[0017] S2. The localized resonant phonon crystal unit cells are fixedly laid on the upper surface of the foundation and the sidewalls of the groove in an array.

[0018] S3. Fix the mounting base to the upper surface of the foundation, with the mounting base located between adjacent local resonant phononic crystal unit cell arrays;

[0019] S4. Place a slider on top of the foundation. The slider is located in the groove of the foundation. One side of the slider is fixedly connected to the local resonant phonon crystal unit cell of the second damping layer.

[0020] S5. Fix the connecting piece on the lower surface of the track plate. The counterweight below the connecting piece corresponds one-to-one with the insertion hole on the fixing seat. Place the track plate on the foundation, insert the counterweight into the insertion hole, and the lower surface of the track plate contacts the upper surface of the first vibration damping layer.

[0021] The advantages and positive effects of the localized resonant phonon crystal unit cell, vibration reduction structure, and installation method described in this invention are:

[0022] 1. Locally resonant phononic crystals exhibit significant effects in low-frequency control. The phononic crystal unit cell proposed in this invention comprises a silicone rubber matrix, a steel scatterer, a soft material encapsulation layer, and a spring-mass subsystem, representing a locally resonant phononic crystal structure design. This design effectively forms multiple complete bandgap and directional bandgap lines in the low-frequency range, fully leveraging the advantages of locally resonant phononic crystals in effectively suppressing low-frequency elastic waves.

[0023] 2. The invention employs a hollowed-out design between the external silicone rubber matrix and the steel scatterer, allowing the silicone rubber and other materials sufficient deformation space to exert their vibration damping effect; the soft material wrapping layer that connects the two also forms a spring-damping system when subjected to external forces, which can also play a certain role in vibration damping.

[0024] 3. The spring mass subsystem combines the advantages of both steel springs and rubber, possessing the advantages of stable performance and strong energy bearing capacity. Embedding it into the steel scatterer helps to improve the elasticity and support of the overall structure, and works together with the external silicone rubber to achieve a dual vibration reduction effect; moreover, since the two are different vibration reduction materials, the vibration reduction range is better.

[0025] 4. In addition to serving as a local resonant phonon crystal structure, the steel scatterer also ensures that the damping layer has sufficient rigidity and continues to provide good support even if easily aged materials such as silicone rubber are damaged.

[0026] 5. Since the steel scatterer can provide sufficient support, the proposed local resonant phononic crystal unit cell design, while ensuring the effectiveness of the selected damping material, allows for flexible selection of materials for the outer ring matrix, cladding layer, and spring mass subsystem, depending on the specific damping objective. By leveraging the overall low-frequency bandgap formed by local resonance and changing the material parameters, the bandgap of the local resonant phononic crystal can be effectively tuned (i.e., low-frequency bandgap shift control) to effectively control low-frequency vibrations in different frequency bands.

[0027] 6. When two or more unit cells are arranged in the horizontal and vertical directions, in addition to the role of multiple spring-damping systems inside the unit cells, spring-damping systems are also formed between the unit cells. Therefore, based on the design of multiple spring-damping systems, not only are local resonance characteristics played out, but periodic characteristics are also further formed, which can play a better vibration reduction role.

[0028] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0029] Figure 1 This is a top view of the phononic crystal unit cell structure of Embodiment 1 of the present invention;

[0030] Figure 2 This is a schematic diagram of the phonon crystal unit cell structure of Embodiment 1 of the present invention;

[0031] Figure 3 This is a schematic diagram of the phononic crystal unit cell structure of Embodiment 1 of the present invention;

[0032] Figure 4 This is a schematic diagram of the phonon crystal unit cell silicone rubber matrix structure of Embodiment 1 of the present invention;

[0033] Figure 5 This is a schematic diagram of the steel scatterer structure of the phonon crystal unit cell in Embodiment 1 of the present invention;

[0034] Figure 6 This is a schematic diagram of the phonon crystal unit cell structure of Embodiment 2 of the present invention;

[0035] Figure 7 This is a top view schematic diagram of the phononic crystal unit cell structure of Embodiment 2 of the present invention;

[0036] Figure 8 This is a schematic diagram of the phononic crystal unit cell structure of Embodiment 2 of the present invention;

[0037] Figure 9 This is a schematic diagram of the three-dimensional structure of the phonon crystal unit cell silicone rubber matrix in Embodiment 2 of the present invention;

[0038] Figure 10 This is a schematic diagram of the cross-sectional structure of the phonon crystal unit cell silicone rubber matrix in Embodiment 2 of the present invention;

[0039] Figure 11 This is a three-dimensional structural diagram of the vibration reduction structure in Embodiment 3 of the present invention;

[0040] Figure 12 This is a front view schematic diagram of the vibration reduction structure in Embodiment 4 of the present invention;

[0041] Figure 13 This is a partial structural diagram of the vibration reduction structure in Embodiment 4 of the present invention;

[0042] Figure 14 This is a schematic diagram of the first damping layer structure of the damping structure in Embodiment 4 of the present invention;

[0043] Figure 15 This is a schematic diagram of the vibration damping component according to Embodiment 4 of the present invention;

[0044] Figure 16 This is a partial structural schematic diagram of the vibration damping component in Embodiment 4 of the present invention;

[0045] Figure 17 This is a partial structural diagram of the first damping layer in Embodiment 3 of the present invention;

[0046] Figure 18 This is a band structure diagram of the phononic crystal unit cell of Embodiment 1 of the present invention;

[0047] Figure 19 This refers to the vibration transmission loss of the vibration reduction structure in Embodiment 3 of the present invention;

[0048] Figure 20 This is a time-domain acceleration diagram of the vibration reduction structure in Embodiment 3 of the present invention;

[0049] Figure 21 This is the frequency domain acceleration diagram of the vibration reduction structure in Embodiment 3 of the present invention.

[0050] Figure Labels

[0051] 1. Silicone rubber matrix; 2. Soft material coating layer; 3. Steel scatterer; 4. Spring mass subsystem; 5. Steel spring; 6. Mounting hole; 7. First damping hole; 8. Second damping hole; 9. Track slab; 10. Foundation; 11. First damping layer; 12. Second damping layer; 13. Slider; 14. Damping component; 15. Fixing base; 16. Counterweight; 17. Connecting piece; 18. First buffer boss; 19. Second buffer boss. Detailed Implementation

[0052] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0053] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of any inconsistency, the meaning set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit the scope of this application.

[0054] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0055] Example 1

[0056] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown. A localized resonance phononic crystal unit cell mainly consists of an outer ring of silicone rubber substrate 1, an inner cavity of silicone rubber substrate 1 containing a steel scatterer 3, and a soft material encapsulation layer 2 connecting and fixing the steel scatterer 3 to the silicone rubber substrate 1; four spring mass subsystems 4 are nested within the steel scatterer 3; and the inner cavity sidewall of the silicone rubber substrate 1 is provided with a soft material encapsulation layer 2.

[0057] The spring mass subsystem 4 includes a steel spring 5 and a rubber matrix. The helical steel spring 5 is embedded in the cylindrical rubber matrix, and the height of the steel spring 5 is lower than that of the rubber matrix.

[0058] The silicone rubber matrix 1 and the spring mass subsystem 4 are at the same height, while the steel scatterer 3 is at a lower height than the silicone rubber matrix 1 and the spring mass subsystem 4.

[0059] This invention takes into account the stiffness requirements of the track structure vibration damping pad. The material of the local resonant phonon crystal unit cell structure is composed of silicone rubber, alloy steel and epoxy resin. The steel scatterer 3 and the silicone rubber matrix 1 are connected and fixed by a soft material wrapping layer 2. The four spring mass subsystems 4 are nested inside the steel scatterer 3.

[0060] The outer silicone rubber matrix 1 and the inner steel scatterer 3 of the localized resonant phononic crystal unit cell are designed with a central hollow structure. To improve the vibration reduction effect of the initial unit cell structure, a novel localized resonant phononic crystal unit cell structure can be obtained by adding a spring-mass subsystem 4 inside the initial unit cell structure. This ensures the deformation space of the outer silicone rubber matrix 1 for vibration reduction; the steel scatterer 3 adopts an open design, with four spring-mass subsystems 4 embedded inside.

[0061] The internal steel scatterer 3 and the outer silicone rubber matrix 1 and spring mass subsystem 4 are designed with a height difference. The silicone rubber matrix 1 and spring mass subsystem 4 play the main role in vibration reduction. Since the overall structure of the phonon crystal adopts a hollow design, the overall stiffness of the local resonant phonon crystal unit cell structure will be reduced. In order to increase the overall stiffness and low-frequency band gap of the new local resonant phonon crystal unit cell structure, the steel spring 5 structure and the spring mass subsystem 4 composed of rubber are embedded in the open steel scatterer 3 to form a new composite scatterer structure. The internal steel scatterer 3 and other structures work together to ensure that the vibration damping pad has sufficient support.

[0062] In this embodiment, the silicone rubber substrate 1 has a length × width × height of 80mm × 80mm × 40mm, and the inner cavity of the silicone rubber has a length × width × height of 60mm × 60mm × 37.5mm. The steel scatterer 3 has a length × width × height of 50mm × 50mm × 35mm. The height difference between the steel scatterer 3 and the silicone rubber substrate 1 is 2.5mm. The four mounting holes 6 on the steel scatterer 3 have a diameter of 20mm and are evenly distributed on the steel scatterer 3. The soft material wrapping layer 2 is an L-shaped structure remaining after cutting a rectangular block with a length × width × height of 5mm × 5mm × 3mm from a rectangular block with a length × width × height of 10mm × 10mm × 3mm. In the spring mass subsystem 4, the diameter of the rubber substrate is 20mm and the length is 37.5mm; the length of the steel spring 5 is 20mm, and the steel spring 5 is located at the center of the rubber substrate.

[0063] In this embodiment, the inner cavity of the silicone rubber matrix 1 can also be a through hole penetrating the silicone rubber matrix 1. The length of the rubber matrix is ​​40mm, and it is the same height as the silicone rubber matrix 1. The height difference between the two ends of the steel scatterer 3 and the two ends of the silicone rubber matrix 1 is 2.5mm.

[0064] Example 2

[0065] like Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown. A localized resonance phononic crystal unit cell mainly consists of an outer ring of silicone rubber substrate 1, an inner cavity of silicone rubber substrate 1 containing a steel scatterer 3, and a soft material encapsulation layer 2 connecting and fixing the steel scatterer 3 to the silicone rubber substrate 1; four spring mass subsystems 4 are nested within the steel scatterer 3; and the inner cavity sidewall of the silicone rubber substrate 1 is provided with a soft material encapsulation layer 2.

[0066] The spring mass subsystem 4 includes a steel spring 5 and a rubber matrix. The helical steel spring 5 is embedded in the cylindrical rubber matrix, and the height of the steel spring 5 is lower than that of the rubber matrix.

[0067] The silicone rubber matrix 1 and the spring mass subsystem 4 are at the same height, while the steel scatterer 3 is at a lower height than the silicone rubber matrix 1 and the spring mass subsystem 4.

[0068] This invention takes into account the stiffness requirements of the track structure vibration damping pad. The material of the local resonant phonon crystal unit cell structure is composed of silicone rubber, alloy steel and epoxy resin. The steel scatterer 3 and the silicone rubber matrix 1 are connected and fixed by a soft material wrapping layer 2. The four spring mass subsystems 4 are nested inside the steel scatterer 3.

[0069] The outer silicone rubber matrix 1 and the inner steel scatterer 3 of the localized resonant phononic crystal unit cell are designed with a central hollow structure. To improve the vibration reduction effect of the initial unit cell structure, a novel localized resonant phononic crystal unit cell structure can be obtained by adding a spring-mass subsystem 4 inside the initial unit cell structure. This ensures the deformation space of the outer silicone rubber matrix 1 for vibration reduction; the steel scatterer 3 adopts an open design, with four spring-mass subsystems 4 embedded inside.

[0070] The internal steel scatterer 3 and the outer silicone rubber matrix 1 and spring mass subsystem 4 are designed with a height difference. The silicone rubber matrix 1 and spring mass subsystem 4 play the main role in vibration reduction. Since the overall structure of the phonon crystal adopts a hollow design, the overall stiffness of the local resonant phonon crystal unit cell structure will be reduced. In order to increase the overall stiffness and low-frequency band gap of the new local resonant phonon crystal unit cell structure, the steel spring 5 structure and the spring mass subsystem 4 composed of rubber are embedded in the open steel scatterer 3 to form a new composite scatterer structure. The internal steel scatterer 3 and other structures work together to ensure that the vibration damping pad has sufficient support.

[0071] A first vibration damping hole 7 is provided on the silicone rubber substrate 1. The first vibration damping hole 7 is located around the silicone rubber substrate 1 and penetrates the silicone rubber substrate 1. The first vibration damping hole 7 is evenly distributed around the silicone rubber substrate 1. The first vibration damping hole 7 has a spindle-shaped structure with small openings at both ends and a large opening in the middle. The diameter of the first vibration damping hole 7 at both ends is 2mm, and the diameter of the middle part is 6mm.

[0072] The first vibration damping hole 7 primarily buffers and absorbs horizontal vibrations, reducing the transmission of vibrations to the base 10. The spindle-shaped structure, with its smaller ends and larger center, provides greater deformation space for the silicone rubber matrix 1 in the horizontal direction. When subjected to horizontal vibration, the silicone rubber matrix 1 undergoes elastic deformation along the extension direction of the hole. The large space in the middle allows for greater tensile or compressive deformation of the material. The elastic damping properties of silicone rubber convert vibration energy into heat energy, thereby reducing vibration transmission efficiency.

[0073] In addition, the structure of the spindle-shaped hole changes the propagation path of sound waves. After the sound waves enter the hole, because the cross-section of the hole gradually increases from both ends to the middle, the sound waves undergo multiple reflections, refractions, and interferences within the hole. During the reflection process, some of the sound waves cancel each other out. At the same time, the silicone rubber material itself has a certain absorption effect on sound waves, which, together with the vibration damping of the air column inside the hole, further consumes sound energy and achieves a noise reduction effect.

[0074] A plurality of second vibration damping holes 8 are evenly arranged on the bottom surface of the silicone rubber substrate 1, and the second vibration damping holes 8 penetrate through the bottom of the silicone rubber substrate 1. The second vibration damping holes 8 are conical structures with a larger opening at the top and a smaller opening at the bottom. The diameter of the top opening of the second vibration damping hole 8 is 5 mm, and the diameter of the bottom opening is 2 mm.

[0075] The second vibration damping hole 8 primarily buffers vertical vibrations, reducing their transmission. The conical structure, with its larger top and smaller bottom, allows the silicone rubber matrix 1 to expand and deform outwards along the inclined walls of the conical hole when subjected to vertical pressure. The large opening at the top allows for greater initial deformation space, while the smaller opening at the bottom provides support by constraining deformation, preventing excessive deformation. Through this synergistic buffering and constraint effect, the elastic deformation of the silicone rubber absorbs vertical vibration energy, reducing the transmission efficiency of vibration to the foundation 10. Vertical sound waves entering the conical hole from the top are compressed and reflected multiple times within the hole due to the gradually decreasing cross-section. The silicone rubber material on the hole wall absorbs some of the sound energy. Simultaneously, the impedance difference at different cross-sections of the conical structure causes impedance mismatch during sound wave propagation, reflecting some sound waves back to the source, further absorbing the sound and improving the noise reduction effect.

[0076] The first damping hole 7 and the second damping hole 8 are designed to handle vibrations and sound waves in the horizontal and vertical directions, respectively, and are adapted to the force and energy propagation characteristics in different directions through differentiated structural designs. Together, they dampen vibrations in multiple dimensions, and at the same time, by changing the vibration energy transmission path, enhancing the energy dissipation of material deformation, and optimizing the sound wave reflection / absorption efficiency, they jointly improve the overall vibration damping and noise reduction performance of the local resonant phononic crystal unit cell.

[0077] Example 3

[0078] like Figure 11 , Figure 17 As shown, a vibration damping structure includes a first damping layer 11 and a second damping layer 12, both of which are composed of locally resonant phonon crystal units as described in Embodiment 1 or Embodiment 2. The first damping layer 11 is fixedly laid on the upper surface of the foundation 10, and the second damping layer 12 is located on both sides of the track slab 9. Both the first damping layer 11 and the second damping layer 12 are located between the track slab 9 and the foundation 10.

[0079] The foundation 10 has grooves on both sides, and the second vibration damping layer 12 is fixedly laid in the grooves. A slider 13 is provided between the second vibration damping layer 12 and the side wall of the track slab 9, and one side of the slider 13 is fixedly connected to the second vibration damping layer 12. The other side of the slider 13 has an inclined surface that gradually slopes towards the track slab 9 from top to bottom. The slider 13 is slidably connected to the foundation 10, and the track slab 9 is slidably connected to the slider 13. The slider 13 can be a precast concrete component or made of steel, and the slider 13 supports the track slab 9 through the inclined surface. PTFE rubber pads can be provided on the contact surface between the slider 13 and the track slab 9 as needed to reduce the friction between the slider 13 and the track slab 9.

[0080] The first damping layer 11 mainly addresses the vertical vibrations generated by the track slab 9. The second damping layer 12 mainly addresses the lateral vibrations generated by the track slab 9 under train loads. The second damping layer 12 is laid in the groove of the foundation 10. The groove structure constrains the direction of vibration transmission, so that the lateral vibration energy is mainly dissipated through the unit cell structure of the second damping layer 12, preventing the vibration from spreading disorderly to the side of the foundation 10, and improving the directionality and efficiency of vibration damping.

[0081] The inclined surface on one side of the slider 13 converts the lateral displacement of the track plate 9 into the sliding displacement of the slider 13 along the base 10. When the track plate 9 vibrates laterally, the inclined surface is subjected to force, causing the slider 13 to slide along the base 10, converting the rigid lateral impact force into frictional energy dissipation during the sliding process. At the same time, through the fixed connection between the slider 13 and the second damping layer 12, the remaining energy is transferred to the cellular structure of the second damping layer 12 for further absorption, thereby improving the damping effect.

[0082] Example 4

[0083] like Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown, a vibration damping structure includes a first damping layer 11 and a second damping layer 12. Both the first damping layer 11 and the second damping layer 12 are composed of localized resonant phonon crystal units as described in Embodiment 1 or Embodiment 2. The first damping layer 11 is fixedly laid on the upper surface of the foundation 10, and the second damping layer 12 is located on both sides of the track slab 9. Both the first damping layer 11 and the second damping layer 12 are located between the track slab 9 and the foundation 10.

[0084] The foundation 10 has grooves on both sides, and the second vibration damping layer 12 is fixedly laid in the grooves. A slider 13 is provided between the second vibration damping layer 12 and the side wall of the track slab 9, and one side of the slider 13 is fixedly connected to the second vibration damping layer 12. The other side of the slider 13 has an inclined surface that gradually slopes towards the track slab 9 from top to bottom. The slider 13 is slidably connected to the foundation 10, and the track slab 9 is slidably connected to the slider 13. The slider 13 can be a precast concrete component or made of steel, and the slider 13 supports the track slab 9 through the inclined surface. PTFE rubber pads can be provided on the contact surface between the slider 13 and the track slab 9 as needed to reduce the friction between the slider 13 and the track slab 9.

[0085] A plurality of vibration damping elements 14 are provided on the upper surface of the foundation 10, and the vibration damping elements 14 are distributed in a linear array on the upper surface of the foundation 10. The vibration damping elements 14 are located between adjacent first vibration damping layers 11. The vibration damping elements 14 include a fixing seat 15, which is fixedly mounted on the upper surface of the foundation 10. A plurality of insertion holes are evenly arranged on the fixing seat 15, and a counterweight 16 is disposed in the insertion hole. The counterweight 16 is slidably connected to the fixing seat 15. A connecting piece 17 is fixedly mounted on the top of the counterweight 16, and the counterweight 16 is fixedly connected to the track plate 9 through the connecting piece 17.

[0086] like Figure 16 As shown. The side wall of the socket is provided with several elastic first buffer bosses 18 that are inclined inward and downward, and the two sides of the counterweight block 16 are provided with elastic second buffer bosses 19 that are inclined outward and upward. The first buffer bosses 18 and the second buffer bosses 19 overlap.

[0087] The fixing block is made of alloy steel and provides good support for the track slab 9. The counterweight 16 is made of alloy steel, and the connecting piece 17 is a thin metal sheet with a certain rigidity, which can move the counterweight 16. The first buffer boss 18 and the second buffer boss 19 are both made of silicone rubber.

[0088] The counterweight 16 has a large mass. When the track slab 9 vibrates due to the train load, the vibration is transmitted to the counterweight 16 through the connecting piece 17, causing the counterweight 16 to vibrate synchronously. The large mass of the counterweight 16 creates a resonance effect through its own vibration (especially low-frequency vibration), converting the vibration energy of the track slab 9 into its own kinetic and potential energy, reducing the direct transmission of vibration to the fixed seat 15 and the foundation 10, thereby specifically attenuating low-frequency vibration and improving the vibration reduction effect for low frequencies. The counterweight 16 is slidably connected to the fixed seat 15. During its vibration, the relative movement between the counterweight 16 and the fixed seat 15, combined with its own mass inertia, buffers the impact vibration of the track slab 9 through the "mass-inertia" effect, reducing the vibration transmission efficiency.

[0089] When the counterweight 16 moves downward under the action of the connecting piece 17, the first buffer boss 18 and the second buffer boss 19, made of silicone rubber, overlap and generate friction. The inclined structure of the two bosses causes the contact surfaces to slide relative to each other along the inclined direction when the counterweight 16 moves downward. The silicone rubber material itself has a high coefficient of friction and damping characteristics. During the sliding friction process, the vibration energy is converted into heat energy and consumed, directly attenuating the vibration energy in the vertical direction and improving the vibration reduction effect. Both the first and second buffer bosses 19 are elastic structures. During the friction process, they undergo elastic deformation due to the force. The elastic restoring force of the silicone rubber further absorbs the vibration impact, forming a dual damping effect of friction energy consumption and elastic buffering. This reduces the rigid collision between the counterweight 16 and the fixed seat 15, avoids the transmission of vibration energy to the foundation 10 through rigid contact, and reduces the secondary vibration noise that may be generated during the friction process. The first and second buffer platforms are inclined in opposite directions. When the track plate 9 moves upward, the first and second buffer platforms have greater frictional resistance due to their inclined structure, which can buffer the impact force of the track plate 9 and protect the track plate 9.

[0090] The installation method of the above-mentioned vibration damping structure includes the following steps:

[0091] S1. Assemble the local resonant phonon crystal unit cell, fix the soft material coating layer 2 at the four corners of the inner cavity sidewall of the silicone rubber substrate 1, insert the steel scatterer 3 into the cavity, fix the steel scatterer 3 to the soft material coating layer 2, and fix the spring mass subsystem 4 into the mounting hole 6 of the steel scatterer 3.

[0092] S2. The localized resonant phonon crystal unit cell array is fixedly laid on the upper surface of the base 10 and the side wall of the groove.

[0093] S3. Fix the fixing seat 15 on the upper surface of the base 10. The fixing seat 15 is located between adjacent local resonant phonon crystal unit cell arrays.

[0094] S4. Place slider 13 above base 10. Slider 13 is located in the groove of base 10. One side of slider 13 is fixedly connected to the local resonant phonon crystal unit cell of the second damping layer 12.

[0095] S5. Fix the connecting piece 17 on the lower surface of the track plate 9. The counterweight 16 below the connecting piece 17 corresponds one-to-one with the insertion hole on the fixing seat 15. Place the track plate 9 on the foundation 10, insert the counterweight 16 into the insertion hole, and the lower surface of the track plate 9 contacts the upper surface of the first vibration damping layer 11.

[0096] The band gap of the unit cell of the localized resonance phononic crystal described in Example 1 was calculated, and the band structure was obtained, as shown below. Figure 18 As shown in the figure, the cell design scheme proposed in this invention can form good full bandgap and directional bandgap in the low-frequency range of 0-100Hz, indicating a very good vibration suppression effect on low-frequency vibrations. The combination of full bandgap and directional bandgap not only ensures all-round isolation of low-frequency vibrations but also adapts to the vibration propagation characteristics in different directions, thus improving the vibration reduction effect.

[0097] Figure 19 This refers to the vibration transmission loss of the vibration reduction structure in Embodiment 3 of the present invention. For example... Figure 19 As shown, for low-frequency vibrations of 1Hz-50Hz, the vibration attenuation can reach 70dB. For low-frequency vibrations of 1Hz-80Hz, the vibration attenuation reaches 45.53dB. This indicates that the vibration reduction structure described in this embodiment has a very good attenuation effect on low-frequency vibrations and can effectively suppress them. It also has a relatively stable attenuation capability for high-frequency vibrations above 150Hz.

[0098] The vibration reduction structure described in Example 3 was subjected to time-domain and frequency-domain acceleration descriptions, and the results are as follows: Figure 20 , Figure 21 As shown, the peak vibration acceleration of the vibration damping structure described in Embodiment 3 of the present invention is significantly smaller than that of ordinary silicone rubber vibration damping structures. The overall amplitude of the vibration damping structure described in Embodiment 3 of the present invention is significantly reduced across all vibration frequency ranges, especially with significant attenuation in the low-frequency range, effectively suppressing low-frequency vibrations, indicating a good vibration damping effect.

[0099] Therefore, by adopting the local resonant phonon crystal unit cell, vibration reduction structure, and installation method described in this invention, the problem of poor vibration reduction effect of existing vibration reduction measures on low-frequency vibrations can be solved.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A locally resonant phonon crystal unit cell, characterized in that: The system includes a silicone rubber matrix as the outer ring, a steel scatterer within the inner cavity of the silicone rubber matrix, and the steel scatterer and the silicone rubber matrix are connected and fixed by a soft material coating layer; four spring mass subsystems are nested within the steel scatterer; and the inner cavity sidewalls of the silicone rubber matrix are coated with a soft material coating layer. The spring mass subsystem includes a steel spring and a rubber matrix, with the helical steel spring embedded in the cylindrical rubber matrix and the height of the steel spring being lower than that of the rubber matrix. The silicone rubber matrix and the spring mass subsystem are at the same height, while the steel scatterer is at a lower height than the silicone rubber matrix and the spring mass subsystem. A gap is provided between the sidewall of the steel scatterer and the silicone rubber matrix to facilitate the deformation of the silicone rubber matrix, and the height difference between the steel scatterer and the silicone rubber matrix is ​​2mm-4mm. The silicone rubber matrix is ​​provided with a first vibration damping hole, which is located around the silicone rubber matrix and penetrates the silicone rubber matrix. The first vibration damping hole is a spindle-shaped structure with small openings at both ends and a large opening in the middle. Several second vibration damping holes are evenly provided on the bottom surface of the silicone rubber matrix. The second vibration damping holes penetrate the bottom of the silicone rubber matrix and are conical structures with a large opening at the top and a small opening at the bottom.

2. A vibration damping structure, characterized in that: It includes a first damping layer and a second damping layer, both of which are composed of at least one layer of local resonant phonon crystal unit cell as described in claim 1. The first damping layer is laid on the upper surface of the foundation, and the second damping layer is located on both sides of the track slab. Both the first damping layer and the second damping layer are located between the track slab and the foundation.

3. The vibration reduction structure according to claim 2, characterized in that: The foundation has grooves on both sides, and the second damping layer is laid in the grooves. A slider is provided between the second damping layer and the side wall of the track plate. One side of the slider is fixedly connected to the second damping layer, and the other side of the slider is provided with an inclined surface that gradually slopes from the top to the bottom towards the track plate. The slider is slidably connected to the foundation, and the track plate is slidably connected to the slider.

4. The vibration reduction structure according to claim 3, characterized in that: The upper surface of the foundation is provided with a number of vibration damping components, which are distributed in a linear array on the upper surface of the foundation and are located between adjacent first vibration damping layers. Each vibration damping component includes a fixed base, which is fixedly installed on the upper surface of the foundation. The fixed base is evenly provided with a number of insertion holes, and a counterweight is installed in each insertion hole. The counterweight is slidably connected to the fixed base, and a connecting piece is provided on the top of the counterweight. The counterweight is fixedly connected to the track plate through the connecting piece.

5. A vibration reduction structure according to claim 4, characterized in that: The sidewall of the socket is provided with several elastic first buffer bosses that are inclined inward and downward, and the two sides of the counterweight are provided with elastic second buffer bosses that are inclined outward and upward, with the first buffer bosses and the second buffer bosses overlapping.

6. An installation method based on the vibration damping structure according to claim 5, characterized in that, Includes the following steps: S1. Assemble a local resonant phonon crystal unit cell, fix a soft material wrapping layer at the four corners of the inner cavity sidewall of the silicone rubber matrix, insert a steel scatterer into the cavity, fix the steel scatterer to the soft material wrapping layer, and fix a spring mass subsystem into the mounting hole of the steel scatterer. S2. The localized resonant phonon crystal unit cells are fixedly laid on the upper surface of the foundation and the sidewalls of the groove in an array. S3. Fix the mounting base to the upper surface of the foundation, with the mounting base located between adjacent local resonant phononic crystal unit cell arrays; S4. Place a slider on top of the foundation. The slider is located in the groove of the foundation. One side of the slider is fixedly connected to the local resonant phonon crystal unit cell of the second damping layer. S5. Fix the connecting piece on the lower surface of the track plate. The counterweight below the connecting piece corresponds one-to-one with the insertion hole on the fixing seat. Place the track plate on the foundation, insert the counterweight into the insertion hole, and the lower surface of the track plate contacts the upper surface of the first vibration damping layer.

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