Polyurethane damping mat and its forming method and compounding method

Abstract

This invention discloses a polyurethane vibration damping pad based on a composite damping structure, comprising a microporous elastic layer, a high-damping elastic layer, and a metamaterial structure. The microporous elastic layer and the high-damping elastic layer are integrally composited along the thickness direction. Furthermore, the metamaterial structure is embedded in the pores of the high-damping elastic layer and vulcanized therewith to form an integral structure; alternatively, the metamaterial structure is disposed on one side of the high-damping elastic layer and vulcanized therewith to form an integral structure, while simultaneously being embedded in the microporous elastic layer. This invention also discloses a corresponding molding method for the polyurethane vibration damping pad, as well as a method for combining the vibration damping pad with a precast track bed. This invention achieves structural energy dissipation through the interlocking of damping materials and micro-elastic materials. The metamaterial structure further enhances the energy dissipation capacity of the high-performance damping elastic layer, thereby providing excellent transmission attenuation in high-frequency excitation and high damping in low-frequency excitation.

Description

Technical Field

[0001] This invention belongs to the field of track vibration reduction technology, specifically relating to a polyurethane vibration damping pad based on a composite damping structure, the molding of the vibration damping pad, and a method for combining the vibration damping pad with a precast track bed. Background Technology

[0002] With the increasing demand for vibration damping pads in projects such as rail transit and building vibration isolation, vibration isolation technology also needs continuous innovation and improvement.

[0003] Traditional vibration damping pads fall into two main categories: solid elastomeric frustum (or groove) structures and microporous elastomeric foam structures. Solid elastomeric pads utilize compression and shear deformation to convert energy and achieve vibration isolation and reduction. Microporous elastomeric foams achieve vibration isolation and reduction through their compressible volume and nonlinearly designable load-bearing capacity. Both types of products are widely used in practical engineering, each with its own advantages and disadvantages. However, overall, existing products generally suffer from limited low-frequency vibration isolation and reduction effects, and conflicts between energy loss, damping, and material-related parameters. For example, to achieve high energy loss, high damping is required given a fixed static modulus; however, high damping leads to an increase in dynamic modulus, which reduces vibration isolation efficiency. Increased internal material friction leads to increased molecular heat generation, thus increasing the risk of aging.

[0004] Furthermore, traditional vibration damping pads are relatively complicated to manufacture. For example, a vibration damping pad for rail transit disclosed in publication number CN219297871U requires perforation. In terms of construction, three sets of screws need to be inserted and then aligned and tightened to fix the vibration damping pad.

[0005] Furthermore, with the increasingly widespread use of precast slab track bed vibration damping pads, the requirements for their ease of construction, efficiency, and cost control are becoming increasingly stringent. However, the traditional composite method of precast slab track bed and vibration damping pads mainly uses adhesives for bonding. This method has the following disadvantages: 1. Increased handling frequency; 2. High adhesive cost; 3. Low adhesive bonding efficiency. Therefore, it is necessary to optimize the composite scheme of precast slab track bed and vibration damping pads. Summary of the Invention

[0006] In response to one or more of the above-mentioned defects or improvement needs of the prior art, the present invention provides a polyurethane vibration damping pad and its molding and composite methods. By interlocking damping materials and micro-elastic materials, structural energy dissipation is achieved. The metamaterial structure further enhances the energy dissipation capacity of the high-performance damping elastic layer, thereby providing excellent transmission attenuation in high-frequency excitation and high damping in low-frequency excitation.

[0007] To achieve the above objectives, according to the first aspect of the present invention, a polyurethane vibration damping pad based on a composite damping structure is provided, comprising a microporous elastic layer, a high-damping elastic layer, and a metamaterial structure.

[0008] The microporous elastic layer and the high-damping elastic layer are integrally composited along the thickness direction; and...

[0009] The metamaterial structure is embedded in the pores of the high-damping elastic layer and vulcanized therewith to form an integral structure; or, the metamaterial structure is disposed on one side of the high-damping elastic layer and vulcanized therewith to form an integral structure, while the metamaterial structure is embedded in the microporous elastic layer.

[0010] As a further improvement of the present invention, a plurality of arrayed pores are formed in the high-damping elastic layer along its thickness direction, and the metamaterial structure is embedded in the pores of the high-damping elastic layer; the pores formed in the high-damping elastic layer are preferably frustum conical structures.

[0011] As a further improvement of the present invention, the metamaterial structure is disposed on one side of the high-damping elastic layer and arranged in an array on that side; the metamaterial structure is preferably a frustum conical, cylindrical or spherical structure.

[0012] As a further improvement of the present invention, the metamaterial structure is made of one or more of crystalline silicon and calcium minerals; and / or, the microporous elastic layer is made of polyurethane material; and / or, the high-damping elastic layer is made of butyl rubber material.

[0013] According to a second aspect of the present invention, a method for molding a polyurethane vibration damping pad based on a composite damping structure is provided, comprising the following steps:

[0014] (1) The high-damping elastic layer and metamaterial structure are vulcanized into one;

[0015] The raw material used for the high-damping elastic layer has several arrayed pores along its thickness direction, which are then placed in a mold. Metamaterial crystal particles are filled into the corresponding pores, and the mixture is vulcanized to form a high-damping elastic layer assembly; or...

[0016] First, the metamaterial crystal particles are positioned in the corresponding positions of the mold according to their set shape. Then, the raw materials used for the high-damping elastic layer are put into the mold and vulcanized to form a high-damping elastic layer assembly.

[0017] (2) The high-damping elastic layer assembly is combined with the microporous elastic layer through a microporous polyurethane foaming process to form a polyurethane vibration damping pad based on a composite damping structure.

[0018] As a further improvement of the present invention, step (2) specifically includes the following steps:

[0019] First, the high-damping elastic layer assembly is positioned in a foaming mold, and then the raw materials used for the microporous elastic layer are poured into the foaming mold. After foaming, the high-damping elastic layer assembly and the microporous polyurethane are combined to form a polyurethane vibration damping pad based on a composite damping structure.

[0020] As a further improvement of the present invention

[0021] In step (1), the temperature is controlled at 135~165℃, the pressure at 13~17MPa, and the vulcanization time at 8~10min during the vulcanization process; and / or,

[0022] In step (2), the foaming temperature is controlled at 50~70℃ and the foaming time is 20~30min.

[0023] As a further improvement of the present invention, the metamaterial structure is made of one or more of crystalline silicon and calcium minerals; and / or, the microporous elastic layer is made of polyurethane material; and / or, the high-damping elastic layer is made of butyl rubber material.

[0024] According to a third aspect of the present invention, a composite method for a vibration damping pad and a precast slab track bed is provided, wherein the vibration damping pad is a polyurethane vibration damping pad based on a composite damping structure, or the vibration damping pad is obtained by the molding method described above, comprising the following steps:

[0025] Prepare vibration damping pads, transverse pressure strips, longitudinal pressure strips, and screws; and install the vibration damping pads and each pressure strip using screws to form a vibration damping pad assembly;

[0026] The reinforcing steel bars of the precast slab track bed are tied inside the mold;

[0027] Concrete is poured for the precast track bed at the location where the reinforcing bars are tied.

[0028] After the precast slab track bed concrete is poured, the surface is finished and smoothed.

[0029] Before the concrete sets, the vibration damping pad assembly is pressed into the precast slab track bed with screws, thus forming a composite structure of the vibration damping pad and the precast slab track bed.

[0030] As a further improvement of the present invention, the transverse pressure strip and the longitudinal pressure strip are provided with openings along the width direction of the pressure strip, and the vibration damping pad is provided with openings perpendicular to the thickness direction. The diameter of the holes of the pressure strip and the vibration damping pad matches the corresponding screws.

[0031] In summary, the technical solutions conceived by this invention have the following beneficial effects compared with the prior art:

[0032] (1) The polyurethane vibration damping pad based on the composite damping structure of the present invention has a damping material and a micro-elastic material interlocked, thereby achieving structural energy dissipation. The metamaterial structure further enhances the energy dissipation capacity of the high-performance damping elastic layer. While the interlocking interface increases energy dissipation, the dynamic-to-static ratio of the system is mainly provided by the micro-elastic material, achieving a low dynamic-to-static ratio. The damping is provided by the energy dissipation of the damping material and the interface, which can provide excellent transmission attenuation in high-frequency excitation and high damping in low-frequency excitation. In addition to the energy provided by the material loss factor during the dynamic energy dissipation process, the interface of the composite structure also increases the energy dissipation effect, thereby achieving a more optimized vibration isolation and damping effect.

[0033] (2) The molding method of the polyurethane vibration damping pad based on the composite damping structure of the present invention involves vulcanizing the high-damping elastic layer and the metamaterial together, and then casting it together with the microporous polyurethane. The molding method is simple and easy to operate, using continuous molding of polyurethane micropores and one-time composite molding of the high-damping elastic layer. Furthermore, the interlocking interface is formed on the damping material base layer after the polyurethane is cast. The high fluidity and self-leveling characteristics of the polyurethane material during the casting process enable the structure to achieve self-adaptation. The microporous polyurethane and the high-damping elastic layer structure self-adaptively composite with reliable interface bonding.

[0034] (3) The method of combining vibration damping pads and precast slab track bed of the present invention involves directly pressing the vibration damping pads into the concrete using screws and pressure strips after the concrete surface is finished. This allows the pads to form an integral structure with the precast slab track bed concrete after the concrete has solidified. Furthermore, the pads can be directly hoisted and stacked after demolding, saving the number of times the precast slab track bed needs to be moved. Compared with the adhesive bonding method of the prior art, the screws and pressure strips of the present invention are more economical than adhesives, and the screw and pressure strip bonding method is faster and more convenient than adhesive fixing, thus improving construction efficiency. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a polyurethane vibration damping pad structure based on a composite damping structure in the first embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of a polyurethane vibration damping pad structure based on a composite damping structure in the second embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of a polyurethane vibration damping pad structure based on a composite damping structure in the third embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the installation structure of a polyurethane vibration damping pad assembly based on a composite damping structure according to an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the composite method of precast slab track bed and vibration damping pad in an embodiment of the present invention.

[0040] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-microporous elastic layer, 2-high damping elastic layer, 3-metamaterial structure, 4-vibration damping pad, 5-transverse pressure strip, 6-longitudinal pressure strip, 7-screw. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0042] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to 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 this invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0046] The polyurethane vibration damping pad based on a composite damping structure according to this invention includes a microporous elastic layer 1, a high-damping elastic layer 2, and a metamaterial structure 3. The microporous elastic layer 1 and the high-damping elastic layer 2 are integrally composited along their thickness direction. The metamaterial structure 3 is embedded in the pores of the high-damping elastic layer 2 and vulcanized therewith to form an integral structure; alternatively, the metamaterial structure 3 is disposed on one side of the high-damping elastic layer and vulcanized therewith to form an integral structure, while simultaneously being embedded in the microporous elastic layer 1. The high-damping elastic layer 1 and the metamaterial structure 3 are vulcanized into an integral structure and then cast together with the microporous elastic layer 1 to form an integral structure.

[0047] For example, in Figure 1 In the first embodiment shown, the polyurethane vibration damping pad based on the composite damping structure includes a microporous elastic layer 1 and a high-damping elastic layer 2 integrally cast along the thickness direction. The high-damping elastic layer 2 has a plurality of arrayed pores along its thickness direction. A metamaterial structure 3 is embedded in the pores of the high-damping elastic layer 2, and the interfaces of the high-damping elastic layer 2, the metamaterial structure 3, and the microporous elastic layer 1 are tightly connected. Preferably, the pores in the high-damping elastic layer 2 are through holes, and preferably have a frustum-cone structure, i.e., the vertical cross-section of the metamaterial structure 3 is trapezoidal. This arrangement not only increases the contact area between the metamaterial structure 3 and the high-damping elastic layer 2, but also increases the interface connection area between the metamaterial structure 3 and the microporous elastic layer 1, further enhancing the overall connection strength.

[0048] exist Figure 2 In the second embodiment shown, the polyurethane vibration damping pad based on the composite damping structure includes a microporous elastic layer 1 and a high-damping elastic layer 2 cast integrally along the thickness direction. A metamaterial structure 3, vulcanized integrally with the high-damping elastic layer 2, is disposed on one side of the high-damping elastic layer 2 and arranged in an array on that side. The metamaterial structure 3 is embedded within the microporous elastic layer 1, which not only enhances the connection strength between the high-damping elastic layer 2 and the metamaterial structure 3, but also fully utilizes the vibration damping effect of the metamaterial structure 3 between them. More preferably, the metamaterial structure 3 is a frustum conical structure, that is, the vertical cross-section of the metamaterial structure 3 is a trapezoidal structure, which can further increase the stability of the interface connection.

[0049] exist Figure 3 In the third embodiment shown, the method is similar to the second embodiment, except that the metamaterial structure 3 is a cylindrical or spherical structure, and the arc surface of the cylindrical or spherical structure is combined with the side surface of the high-damping elastic layer 2, that is, the vertical cross-section of the metamaterial structure 3 is a circular structure. It can be understood that, in order to increase the vulcanization stability of the metamaterial structure 3 and the high-damping elastic layer 2, the metamaterial structure 3 and the high-damping elastic layer 2 are preferably in surface contact rather than line contact. That is, the vertical cross-section of the finally formed metamaterial structure 3 (along...) Figure 3 The vertical cross-section shown is a semi-circular structure.

[0050] This invention Figures 1 to 3 The three implementation methods shown are different interlocking interface structures. The above interlocking interface design not only increases energy consumption and improves vibration reduction effect, but also arranges the interlocking structure and form according to the metamaterial structure model to form a structural band gap, so that the set frequency of the vibration isolation system can be reflected or blocked, thereby achieving a higher vibration reduction and isolation effect.

[0051] Preferably, the metamaterial structure 3 of the present invention comprises one or more substances such as crystalline silicon and calcium minerals, and its size is further preferably at the nanometer scale, which can improve the energy dissipation capacity of the high-performance damping elastic layer. More preferably, the metamaterial structure 3 is a composite material structure composed of two or more materials through structural design at the mesoscale.

[0052] It should be noted that the microporous elastic layer 1 can be made of existing polyurethane material, and the high-damping elastic layer can be made of existing butyl rubber.

[0053] The polyurethane vibration damping pad of this invention features a composite damping structure. The microporous elastic layer primarily addresses high-frequency vibration reduction and isolation, while the highly elastic damping layer assists the microporous elastic layer and metamaterial structure in addressing low-frequency vibration isolation. The interlocking interface increases energy dissipation without affecting dynamic stiffness. Through the combined design of the microporous polyurethane and the highly damping elastic layer, the adverse effects of standing waves in the vibration isolation system can be reduced, improving the vibration reduction and isolation effects. The composite structure can also be designed with metamaterials to achieve even better vibration isolation performance. Furthermore, this invention achieves high damping energy dissipation through internal material damping and the interlocking interface, resulting in better rebound at low stiffness, further enhancing the vibration reduction and isolation effects.

[0054] The polyurethane vibration damping pad based on the composite damping structure in this invention is composed of a high-damping elastic layer, a microporous polyurethane layer, and a metamaterial structure. The molding process involves first molding the high-damping elastic layer, then vulcanizing the high-damping elastic layer and the metamaterial structure together, and finally casting the microporous polyurethane along with the high-damping elastic layer and the metamaterial structure according to the corresponding metamaterial structure design, ultimately forming the polyurethane vibration damping pad based on the composite damping structure.

[0055] Specifically, the molding method of the polyurethane vibration damping pad of the composite damping structure according to an embodiment of the present invention includes the following steps:

[0056] (1) The high-damping elastic layer and the metamaterial structure are vulcanized together to form a high-damping elastic layer assembly;

[0057] After cutting the raw materials (such as butyl damping rubber) used for the high-damping elastic layer, several arrayed pores are made along its thickness direction. The material is placed in a mold, and metamaterial crystal particles (such as calcium minerals and crystalline silicon) are filled into the corresponding pores. The temperature is controlled at 135~165℃, the pressure at 13~17MPa, and the curing time is 8~10min to form a high-damping elastic layer assembly.

[0058] Alternatively, metamaterial crystal particles (such as calcium minerals or crystalline silicon) are first positioned in the corresponding positions of the mold according to their set shape. Then, the raw materials used for the high-damping elastic layer (such as butyl damping rubber) are cut into sheets slightly smaller than the product size and placed into the mold. The temperature is controlled at 135~165℃, the pressure at 13~17MPa, and the curing time is 8~10min to form a high-damping elastic layer assembly.

[0059] In addition, the vulcanization process in this step can be carried out using an existing vulcanization press, and the mold used can be selected by those skilled in the art based on the specific size and shape.

[0060] (2) The high-damping elastic layer assembly is combined with polyurethane material through microporous polyurethane foaming process to form a polyurethane vibration damping pad based on composite damping structure.

[0061] First, the high-damping elastic layer assembly is positioned in the foaming mold. Then, the raw materials used for the microporous elastic layer (such as polyurethane material) are poured into the foaming mold. The foaming temperature is controlled at 50~70℃ and the foaming time is 20~30min. By utilizing the adaptive characteristics of the microporous polyurethane and the high-damping elastic layer material structure, the high-damping elastic layer assembly and the microporous polyurethane are combined together to form a polyurethane vibration damping pad based on a composite damping structure.

[0062] Similarly, the foaming mold used in this step can be selected by those skilled in the art based on its specific size and shape.

[0063] In this invention, the high-damping elastic layer is vulcanized with a metamaterial and then cast together with microporous polyurethane. The process involves continuous microporous polyurethane molding and a one-time composite molding of the high-damping elastic layer, resulting in a simple and easy-to-operate molding method. Furthermore, the interlocking interface forms on the damping material base layer after polyurethane casting. The high fluidity and self-leveling properties of the polyurethane during casting allow the structure to self-adapt, resulting in an adaptive composite structure between the microporous polyurethane and the high-damping elastic layer, ensuring reliable interfacial bonding.

[0064] Furthermore, to address the problems arising from the traditional adhesive bonding method used to combine precast slab track beds and vibration damping pads, this invention also provides a method for combining vibration damping pads and precast slab track beds, comprising the following steps:

[0065] S1: Prepare vibration damping pads, transverse pressure strips, longitudinal pressure strips, and screws; and install the vibration damping pads and pressure strips with screws to form a vibration damping pad assembly;

[0066] The transverse and longitudinal pressure strips have openings along their width, while the vibration damping pads have vertical openings along their thickness, with the hole diameter matching the corresponding screw. Different types of screws can be selected as needed.

[0067] like Figure 4 As shown, the vibration damping pad 4 has several transverse pressure strips 5 and longitudinal pressure strips 6 on one side, and screws 7 are provided in the screw holes corresponding to the vibration damping pad 4 and the pressure strips, and are assembled to form a vibration damping pad assembly.

[0068] S2: Binding the reinforcing bars of the precast slab track bed inside the mold;

[0069] S3: Concrete pouring of precast slab track bed at the location where the reinforcing bars are tied;

[0070] S4: After the precast slab track bed concrete is poured, the surface is finished and smoothed.

[0071] S5: Before the concrete initially sets, the vibration damping pad assembly installed in step S1 is pressed into the precast slab track bed with screws, so that the vibration damping pad is in close contact with the precast slab track bed concrete, and the vibration damping pad and the precast slab track bed are compositely formed.

[0072] It should be noted that the operation sequence of the above-mentioned composite method of vibration damping pad and precast slab track bed can be adjusted by those skilled in the art based on experience. For example, in step S1, the step of installing the vibration damping pad and pressure strip with screws to form a vibration damping pad assembly can also be carried out after the precast slab track bed is poured.

[0073] The present invention's method for combining vibration damping pads and precast slab track bed involves pressing the vibration damping pad assembly into the precast slab track bed with screws before the concrete initially sets. This allows the pads to form an integral structure with the precast slab track bed concrete after the concrete has solidified, achieving a stable composite between the vibration damping pads and the precast slab. Furthermore, after the concrete finishing is completed, the vibration damping pads are directly pressed into the concrete using screws and pressure strips. After demolding, they can be directly hoisted and stacked, saving the number of times the precast slab track bed needs to be moved. Compared to existing adhesive bonding methods, the screw and pressure strip method of the present invention is more economical than adhesives, and the screw and pressure strip combination is faster and more convenient than adhesive fixing, thus improving construction efficiency.

[0074] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A polyurethane vibration damping pad based on a composite damping structure, characterized in that, Including microporous elastic layers, high-damping elastic layers, and metamaterial structures; The microporous elastic layer and the high-damping elastic layer are integrally combined along the thickness direction; The metamaterial structure is embedded in the pores of the high-damping elastic layer and vulcanized with it to form an integral structure; the raw material used for the high-damping elastic layer has several arrayed pores along its thickness direction, is placed in a mold, and metamaterial crystal particles are filled into the corresponding pores, and vulcanized to form a high-damping elastic layer assembly; then the high-damping elastic layer assembly is combined with the microporous elastic layer through a microporous polyurethane foaming process to form a polyurethane vibration damping pad based on a composite damping structure. Alternatively, the metamaterial structure array is arranged on one side of the high-damping elastic layer and vulcanized with it to form an integral structure, while the metamaterial structure is embedded in the microporous elastic layer; first, the metamaterial crystal particles are positioned in the corresponding positions of the mold according to their set shape, then the raw materials used for the high-damping elastic layer are put into the mold and vulcanized to form a high-damping elastic layer assembly; then the high-damping elastic layer assembly is combined with the microporous elastic layer through a microporous polyurethane foaming process to form a polyurethane vibration damping pad based on a composite damping structure. The metamaterial structure is made of one or more of crystalline silicon and calcium minerals; the microporous elastic layer is made of polyurethane; and the high-damping elastic layer is made of butyl rubber.

2. The polyurethane vibration damping pad based on a composite damping structure according to claim 1, characterized in that, The pores within the high-damping elastic layer are truncated cones.

3. The polyurethane vibration damping pad based on a composite damping structure according to claim 1, characterized in that, The metamaterial structure is a frustum-shaped, cylindrical, or spherical structure.

4. A molding method for a polyurethane vibration damping pad based on a composite damping structure, characterized in that, Includes the following steps: (1) The high-damping elastic layer and metamaterial structure are vulcanized into one; The raw material used for the high-damping elastic layer has several arrayed pores along its thickness direction, which are then placed in a mold. Metamaterial crystal particles are filled into the corresponding pores, and the mixture is vulcanized to form a high-damping elastic layer assembly; or... First, the metamaterial crystal particles are positioned in the corresponding positions of the mold according to their set shape. Then, the raw materials used for the high-damping elastic layer are put into the mold and vulcanized to form a high-damping elastic layer assembly. (2) The high-damping elastic layer assembly is combined with the microporous elastic layer through a microporous polyurethane foaming process to form a polyurethane vibration damping pad based on a composite damping structure. The metamaterial structure is made of one or more of crystalline silicon and calcium minerals; the microporous elastic layer is made of polyurethane; and the high-damping elastic layer is made of butyl rubber.

5. The molding method of the polyurethane vibration damping pad based on the composite damping structure according to claim 4, characterized in that, Step (2) specifically includes the following steps: First, the high-damping elastic layer assembly is positioned in a foaming mold, and then the raw materials used for the microporous elastic layer are poured into the foaming mold. After foaming, the high-damping elastic layer assembly and the microporous polyurethane are combined to form a polyurethane vibration damping pad based on a composite damping structure.

6. The molding method of the polyurethane vibration damping pad based on the composite damping structure according to claim 4 or 5, characterized in that, In step (1), the temperature is controlled at 135~165℃, the pressure at 13~17MPa, and the vulcanization time at 8~10min during the vulcanization process; and / or, In step (2), the foaming temperature is controlled at 50~70℃ and the foaming time is 20~30min.

7. A composite method for a vibration damping pad and a precast slab track bed, wherein the vibration damping pad is a polyurethane vibration damping pad based on a composite damping structure as described in any one of claims 1-3, or the vibration damping pad is obtained by the molding method as described in any one of claims 4-6, characterized in that, Includes the following steps: Prepare vibration damping pads, transverse pressure strips, longitudinal pressure strips, and screws; and install the vibration damping pads and each pressure strip using screws to form a vibration damping pad assembly; The reinforcing steel bars of the precast slab track bed are tied inside the mold; Concrete is poured for the precast track bed at the location where the reinforcing bars are tied. After the precast slab track bed concrete is poured, the surface is finished and smoothed. Before the concrete sets, the vibration damping pad assembly is pressed into the precast slab track bed with screws, thus forming a composite structure of the vibration damping pad and the precast slab track bed.

8. The composite method of vibration damping pad and precast slab track bed according to claim 7, characterized in that, The transverse and longitudinal pressure strips have openings along their width direction, and the vibration damping pads have openings perpendicular to their thickness direction. The diameters of the holes in the pressure strips and vibration damping pads match the corresponding screws.

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