A vibration and noise reduction superstructure design method and metamaterial basic unit

Abstract

The present invention discloses a vibration-damping and noise-reducing superstructure design method, comprising the following steps: S1. Obtaining basic parameters and design input information of a base structure; S2. Calculating the original wave dynamics characteristics of the base structure to obtain the basic wave form of the base structure; S3. Introducing an additional mass cost as a constraint condition, updating the calculated wave dynamics characteristics of the base structure to obtain multiple acoustically weak frequency points; S4. Conducting structural design of a metamaterial basic unit; S5. Layout design of the metamaterial basic unit to form a vibration-damping and noise-reducing superstructure; S6. Calculating the wave dynamics characteristics of the vibration-damping and noise-reducing superstructure and comparing and judging them with target design indicators A and B, and continuously running the program until both target A and target B are met. The present invention also specifically discloses a metamaterial basic unit. The present invention has the advantage of being able to effectively reduce vibration and noise at different frequencies while meeting lightweight requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration and noise control, and in particular to a vibration and noise reduction superstructure design method and a metamaterial basic unit. Background Art

[0002] Vibration and noise problems are widespread in major equipment and facilities such as high-speed trains, aircraft, ships, wind tunnels, and substations. Excessive mechanical vibration can cause surface damage and loosening of the structure at the very least, and can lead to structural fatigue, fracture, and even serious accidents such as system failure. In addition, excessive vibration can radiate noise, reduce the acoustic and vibration quality of the equipment and facilities, and cause environmental noise pollution.

[0003] For high-frequency vibration noise, due to its short wavelength and weak transmission capacity, the use of conventional damping materials can achieve good vibration and noise reduction effects. However, for low-frequency vibration noise, traditional structures can only suppress it by increasing the structural mass and spatial dimensions. However, excessive increases in mass and spatial dimensions are unacceptable in practical engineering applications. Recent developments in acoustic metamaterials and metastructures have provided new insights into equipment vibration and noise reduction design. Existing research has shown that acoustic metastructures designed using acoustic metamaterial principles (such as locally resonant plate-shaped metamaterials, thin-film metamaterials, and multi-stage internally inserted tubes) can partially overcome mass and spatial dimension limitations at low frequencies. However, their control frequency band is relatively narrow. While series / parallel structural connections or complex supercell designs can broaden the bandwidth to a certain extent, this also comes with the disadvantages of increased mass and size. Furthermore, while existing acoustic metastructure designs have achieved some promising results in vibration and noise reduction, they are mostly designed for specific applications and lack scalable, general design control methods. These limitations undoubtedly limit the widespread application of acoustic metastructures in engineering. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a vibration and noise reduction superstructure design method that can achieve effective vibration and noise reduction effects on vibrations of different frequencies while meeting lightweight requirements.

[0005] The present invention further provides a metamaterial basic unit with a simple structure and good vibration and noise reduction effects.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A vibration and noise reduction superstructure design method comprises the following steps:

[0008] S1. Obtain basic parameters and design input information of the infrastructure;

[0009] S2. Calculate the original wave dynamic characteristics of the foundation structure based on the basic parameters of the foundation structure and the design input information to obtain the basic wave shape of the foundation structure;

[0010] S3. Introducing the additional mass cost of the vibration and noise reduction superstructure as a constraint condition, updating the wave dynamic characteristics of the calculation base structure, and obtaining multiple weak frequency points of acoustic vibration;

[0011] S4. Conduct structural design of metamaterial basic units;

[0012] S5. Generating a vibration response morphology diagram, an acoustic radiation response cloud diagram, and a sound insulation particle cloud diagram based on multiple acoustic vibration weak frequency points of the foundation structure, and performing layout design on the metamaterial basic unit to form a vibration and noise reduction superstructure;

[0013] S6. Calculate the wave dynamic characteristics of the vibration and noise reduction superstructure and compare them with the target design indicators A and B. Target A refers to the target frequency range, and target B refers to the vibration reduction value, sound radiation suppression value, and sound insulation value within this range. If neither target A nor target B is met, return to step S4. If target A is met but target B is not met, return to step S5 until both target A and target B are met.

[0014] As a further improvement of the above technical solution:

[0015] The step S4 includes

[0016] M1, initially set the resonant mass of the metamaterial basic unit to Mr0, and set the resonant frequency of the metamaterial basic unit to the first acoustic vibration weak frequency fr0;

[0017] M2, so that Mr0 and fr0 satisfy the resonant stiffness kr0 of the basic unit of the metamaterial, (2×π×fr0) 2 ×Mr0= kr0;

[0018] M3, the resonant mass of the main mass unit is assigned as Mr01, and the resonant mass of the auxiliary mass unit is assigned as Mr02, Mr01+Mr02= Mr0;

[0019] M4. Material selection and determination of the geometric dimensions of the main mass element and auxiliary mass element;

[0020] M5. Based on the geometric dimensions of the main mass element and the auxiliary mass element, the geometric dimensions of the elastic element are reversely designed, and the tuning gap is determined so that the resonant frequency of the metamaterial basic unit is equal to fr0.

[0021] The step S5 includes

[0022] N1. Calculate the number of metamaterial basic units Nr that need to be set, Nr = Mmax / Mr0;

[0023] N2. Draw the vibration response morphology diagram, sound radiation response cloud diagram and sound insulation particle cloud diagram of the foundation structure at each weak frequency point of acoustic vibration, and discretely arrange Nr points at the position with the largest response in these diagrams;

[0024] N3. Arrange the basic units of the metamaterial at discrete points.

[0025] The basic parameters of the infrastructure in step S1 include: the material, configuration and size of the infrastructure; the design input information includes the target frequency range, target vibration reduction value, target sound radiation suppression value, target sound insulation value, additional mass limit Mmax, boundary conditions and maximum size.

[0026] The wave dynamics characteristics include vibration response characteristics, sound radiation response characteristics and sound insulation characteristics.

[0027] The infrastructure may be a plate or a beam or a rod or a shell or a cylinder or a vehicle floor or a cabin wall or a track or a sound barrier or a pipeline or a mailbox or a transformer box or an air conditioning box.

[0028] A metamaterial basic unit includes an elastic element, a main mass element, an auxiliary mass element and a tuning gap;

[0029] The elastic primitive is used to provide resonance stiffness and support the main mass primitive and the auxiliary mass primitive;

[0030] The main mass primitive is used to provide a resonant main mass;

[0031] The auxiliary mass primitive is used to provide a resonant auxiliary mass;

[0032] The tuning gap is used to provide vibration reduction space for the auxiliary mass element;

[0033] The main mass element is arranged on the elastic element, a mounting hole is provided on the main mass element, the auxiliary mass element is installed in the mounting hole, the tuning gap is located between the auxiliary mass element and the hole wall of the mounting hole, and the auxiliary mass element is provided with an anti-detachment portion for preventing the auxiliary mass element from detaching from the mounting hole.

[0034] As a further improvement of the above technical solution:

[0035] Along the forward / reverse direction of the resonant motion of the metamaterial basic unit, the maximum value of the tuning gap is recorded as Ld, the resonant amplitude of the metamaterial basic unit is recorded as H, and Ld≤3×H.

[0036] The elastic primitive is a spring, a solid or hollow cylinder, a prism, or a special-shaped structure with elasticity, and the main mass primitive is a cylinder, a rhombus, a cuboid, a cube, a hexagonal honeycomb, or a sphere.

[0037] The mounting hole is a through hole, the auxiliary mass element is passed through the hole, and both ends extend outward, and the anti-slip portion is detachably connected to the two ends of the auxiliary mass element; or the mounting hole is a stepped hole with a small entrance and a large inside, one end of the auxiliary mass element is arranged in the stepped hole, and the other end extends outside the stepped hole, and the anti-slip portion is arranged on the extended end; or the mounting hole is a threaded hole, and the anti-slip portion is an external thread that cooperates with the threaded hole.

[0038] Compared with the prior art, the advantages of the present invention are:

[0039] The vibration and noise reduction superstructure design method disclosed in the present invention first calculates the original wave dynamic characteristics of the base structure to obtain the basic wave shape of the base structure. The mass of the vibration and noise reduction superstructure is then used as an additional constraint condition to enable the vibration and noise reduction superstructure to be innovatively designed while meeting lightweight requirements. The wave dynamic characteristics of the base structure are updated under the constraint condition to obtain multiple acoustic vibration weak frequency points. A vibration response morphology diagram, an acoustic radiation response cloud diagram, and a sound insulation particle cloud diagram are then plotted based on the acoustic vibration weak frequency points of the base structure. Based on these three characteristic diagrams, metamaterial basic units are laid out to form a vibration and noise reduction superstructure. After the layout is completed, the vibration and noise reduction effect of the vibration and noise reduction superstructure is verified. A target frequency A, a target vibration reduction value, an acoustic radiation suppression value, and a sound insulation value B are set. The design and layout process of the metamaterial basic units is repeated until the vibration and noise reduction superstructure achieves the target vibration and noise reduction effect within the set frequency A range. This vibration and noise reduction superstructure design method not only meets the lightweight requirements, but also adjusts the design and layout of the metamaterial basic unit according to the target frequency, ensuring that the purpose of efficient vibration and noise reduction can be achieved within the low-frequency and high-frequency width range.

[0040] The vibration reduction and noise reduction superstructure design method disclosed in the present invention is not restricted by the controlled object and can meet the control requirements of various vibration reduction and noise reduction objects. It has fast design speed, good universality and strong applicability. It can provide methodological guidance for the vibration reduction and noise reduction design of various vibration reduction and noise reduction objects and greatly improve the development efficiency of vibration reduction and noise reduction solutions.

[0041] The metamaterial basic unit disclosed in the present invention has an elastic element that provides resonant stiffness and support, and the elastic element itself also plays a role in reducing vibration and noise. The main mass element and the auxiliary mass element provide resonant mass, and the tuning gap provides a vibration reduction activity space for the auxiliary mass element, so that the auxiliary mass element has a certain degree of freedom in the vibration direction. The metamaterial basic unit used for vibration reduction and noise reduction can achieve damping amplification and efficiency enhancement, and frequency band coupling broadening through the local resonance effect, nonlinear collision and wall friction coupling effect of the metamaterial basic unit, thereby effectively suppressing the generation of structural vibration and radiation noise, and achieving efficient vibration reduction and noise reduction effect; at the same time, the auxiliary mass element is provided with an anti-detachment part to ensure its installation stability, so that it has the advantages of high stiffness and high stability while maintaining light weight and small size, and effectively suppressing the transmission of vibration waves and reducing sound radiation efficiency in a low-frequency and wide-band range, thereby solving the key problems of the existing technology such as weak low-frequency and wide-band capability, large size and low stiffness. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a flow chart of the vibration and noise reduction superstructure design method of the present invention.

[0043] Figure 2 This is a diagram showing the vibration reduction and noise reduction effects of the vibration reduction and noise reduction superstructure of the present invention.

[0044] Figure 3 It is a structural diagram of the second embodiment of the metamaterial basic unit of the present invention.

[0045] Figure 4 It is a structural diagram of Example 3 of the metamaterial basic unit of the present invention.

[0046] Figure 5 It is a structural diagram of Example 4 of the metamaterial basic unit of the present invention.

[0047] Figure 6 This is a schematic structural diagram of a second embodiment of the metamaterial basic unit of the present invention applied to a base structure of a plate to form a vibration-reducing and noise-reducing superstructure.

[0048] Figure 7 This is a schematic structural diagram of a metamaterial basic unit according to a third embodiment of the present invention applied to a base structure of a plate to form a vibration-reducing and noise-reducing superstructure.

[0049] Figure 8 This is a schematic structural diagram of a fourth embodiment of the metamaterial basic unit of the present invention applied to a base structure of a plate to form a vibration-reducing and noise-reducing superstructure.

[0050] Figure 9 This is a schematic structural diagram of a third embodiment of the metamaterial basic unit of the present invention applied to a base structure having a larger plate area to form a vibration-reducing and noise-reducing superstructure.

[0051] Figure 10 This is a structural diagram of the second embodiment of the metamaterial basic unit of the present invention applied to a hollow cylinder as the base structure to form a vibration and noise reduction superstructure.

[0052] The numbers in the figure represent:

[0053] 1. Elastic element; 2. Main mass element; 3. Auxiliary mass element; 31. Anti-slip part; 4. Tuning gap; 5. Mounting hole. DETAILED DESCRIPTION

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0055] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0056] 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 the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0057] In the present invention, unless otherwise expressly specified or limited, terms such as "assemble," "connect," "connect," and "fix" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0058] Example 1

[0059] Figure 1 and Figure 2 An embodiment of the vibration reduction and noise reduction superstructure design method of the present invention is shown. The vibration reduction and noise reduction superstructure design method of this embodiment includes the following steps:

[0060] S1. Obtain basic parameters and design input information of the infrastructure;

[0061] S2. Calculate the original wave dynamic characteristics of the foundation structure based on the basic parameters of the foundation structure and the design input information to obtain the basic wave shape of the foundation structure;

[0062] S3. Introducing the additional mass cost of the vibration and noise reduction superstructure as a constraint condition, updating the wave dynamic characteristics of the calculation base structure, and obtaining multiple weak frequency points of acoustic vibration;

[0063] S4. Conduct structural design of metamaterial basic units;

[0064] S5. Generating a vibration response morphology diagram, an acoustic radiation response cloud diagram, and a sound insulation particle cloud diagram based on multiple acoustic vibration weak frequency points of the foundation structure, and performing layout design on the metamaterial basic unit to form a vibration and noise reduction superstructure;

[0065] S6. Calculate the wave dynamic characteristics of the vibration and noise reduction superstructure and compare them with the target design indicators A and B. Target A refers to the target frequency range, and target B refers to the vibration reduction value, sound radiation suppression value, and sound insulation value within this range. If neither target A nor target B is met, return to step S4. If target A is met but target B is not met, return to step S5 until both target A and target B are met.

[0066] This vibration and noise reduction superstructure design method first calculates the original wave dynamics characteristics of the base structure to obtain the basic wave shape of the base structure. The mass of the vibration and noise reduction superstructure is then used as an additional constraint to ensure that the vibration and noise reduction superstructure is designed while meeting lightweight requirements. The wave dynamics characteristics of the base structure are updated under the constraints to obtain multiple acoustic weak frequency points. Then, a vibration response morphology diagram, an acoustic radiation response cloud diagram, and a sound insulation particle cloud diagram are plotted based on the acoustic weak frequency points of the base structure. Based on these three characteristic diagrams, metamaterial basic units are laid out to form a vibration and noise reduction superstructure. After the layout is completed, the vibration and noise reduction effect of the vibration and noise reduction superstructure is verified. A target frequency A, a target vibration reduction value, an acoustic radiation suppression value, and a sound insulation value B are set. The design and layout process of the metamaterial basic units is repeated until the vibration and noise reduction superstructure achieves the target vibration and noise reduction effect within the set frequency A range. This vibration and noise reduction superstructure design method adjusts the design and layout of the metamaterial basic units according to the target frequency while meeting lightweight requirements, ensuring that vibration and noise reduction can be achieved under both high-frequency and low-frequency vibrations.

[0067] Furthermore, in this embodiment, step S4 includes

[0068] M1, initially set the resonant mass of the metamaterial basic unit to Mr0, and set the resonant frequency of the metamaterial basic unit to the first acoustic vibration weak frequency fr0;

[0069] M2, so that Mr0 and fr0 satisfy the resonant stiffness kr0 of the basic unit of the metamaterial, (2×π×fr0) 2 ×Mr0= kr0;

[0070] M3, the resonant mass of the main mass unit 2 is assigned as Mr01, and the resonant mass of the auxiliary mass unit 3 is assigned as Mr02, Mr01+Mr02= Mr0;

[0071] M4. Material selection and determination of the geometric dimensions of the main mass primitive 2 and the auxiliary mass primitive 3;

[0072] M5. Based on the geometric dimensions of the main mass element 2 and the auxiliary mass element 3, the geometric dimensions of the elastic element 1 are reversely designed, and the tuning gap 4 is determined so that the resonant frequency of the metamaterial basic unit is equal to fr0.

[0073] The target resonant mass Mr0 and target resonant frequency fr0 are set so that both meet the resonant stiffness kr0 requirement. The resonant mass Mr0 is then distributed to the primary mass element 2 and the secondary mass element 3. Finally, the material dimensions of the primary mass element 2 and the secondary mass element 3 are selected, and the dimensions of the elastic element 1 and the tuning gap 4 are inferred to ensure that the resonant frequency of the metamaterial unit meets fr0. It should be noted that, based on the wave dynamics of the base material, the first acoustically weak frequency point has large vibrations and strong vibration transmission. Selecting this as fr0 facilitates vibration reduction at other acoustically weak frequency points with smaller vibrations and weaker vibration transmission, reducing the number of operations and improving efficiency.

[0074] Furthermore, in this embodiment, step S5 includes

[0075] N1. Calculate the number of metamaterial basic units Nr that need to be set, Nr = Mmax / Mr0;

[0076] N2. Draw the vibration response morphology diagram, sound radiation response cloud diagram and sound insulation particle cloud diagram of the foundation structure at each weak frequency point of acoustic vibration, and discretely arrange Nr points at the position with the largest response in these diagrams;

[0077] N3. Arrange the basic units of the metamaterial at discrete points.

[0078] By drawing the vibration response morphology diagram, sound radiation response cloud diagram and sound insulation particle cloud diagram of the foundation structure at each weak frequency point of acoustic vibration, the position with the largest response is found, that is, the position with large vibration and strong noise is arranged to achieve the optimal vibration and noise reduction effect.

[0079] Furthermore, in this embodiment, the basic parameters of the infrastructure in step S1 include: the material, configuration, and dimensions of the infrastructure; and the design input information includes the target frequency range, target vibration reduction value, target sound radiation suppression value, target sound insulation value, additional mass limit Mmax, boundary conditions, and maximum dimensions.

[0080] Furthermore, in this embodiment, the wave dynamics characteristics include vibration response characteristics, sound radiation response characteristics, and sound insulation characteristics.

[0081] Furthermore, in this embodiment, the base structure is a plate. Of course, in other embodiments, the base structure may also be a beam, a rod, a shell, a cylinder, a vehicle floor, a cabin wall, a track, a sound barrier, a pipeline, a mailbox, a transformer box, an air conditioning box, or other structures.

[0082] Further, Figure 2 The vibration reduction test effect diagram of the vibration reduction and noise reduction superstructure designed by this design method is shown. As can be seen from the figure, in the range of 100Hz-2000Hz, the structure of the present invention achieves a high-efficiency low-frequency broadband vibration reduction effect.

[0083] Example 2

[0084] Figure 3 An embodiment of a metamaterial basic unit of the present invention is shown. The metamaterial basic unit of this embodiment includes an elastic element 1, a main mass element 2, an auxiliary mass element 3 and a tuning gap 4;

[0085] The elastic element 1 is used to provide resonant stiffness and support the main mass element 2 and the auxiliary mass element 3;

[0086] The main mass primitive 2 is used to provide a resonant main mass;

[0087] The auxiliary mass primitive 3 is used to provide a resonant auxiliary mass;

[0088] The tuning gap 4 is used to provide vibration reduction space for the auxiliary mass element 3;

[0089] The main mass element 2 is arranged on the elastic element 1, and a mounting hole 5 is provided on the main mass element 2. The auxiliary mass element 3 is installed in the mounting hole 5. The tuning gap 4 is located between the auxiliary mass element 3 and the hole wall of the mounting hole 5. The auxiliary mass element 3 is provided with an anti-detachment part 31 for preventing the auxiliary mass element 3 from detaching from the mounting hole 5.

[0090] In the basic unit of the metamaterial, the elastic element 1 provides resonant stiffness and support, and the elastic element 1 itself also plays a role in vibration reduction and noise reduction. The main mass element 2 and the auxiliary mass element 3 provide resonant mass, and the tuning gap 4 provides a vibration reduction activity space for the auxiliary mass element 3, so that the auxiliary mass element 3 has a certain degree of freedom in the vibration direction, achieving the effect of vibration reduction and noise reduction. At the same time, the auxiliary mass element 3 is provided with an anti-slip portion 31 to ensure its installation stability.

[0091] The metamaterial basic unit has an intrinsic resonance mode. When stimulated by external factors, the intrinsic resonance mode of the metamaterial basic unit is induced, resulting in a violent local resonance effect, driving the auxiliary mass element 3 and the main mass element 2 to move rapidly, and promoting intermittent nonlinear collisions between the auxiliary mass element 3 and the main mass element 2, and the back-and-forth movement produces wall friction coupling, achieving damping amplification and efficiency enhancement, and band coupling broadening, thereby effectively suppressing the generation of structural vibration and radiation noise, and achieving efficient vibration reduction and noise reduction effects.

[0092] Furthermore, in the metamaterial basic unit of this embodiment, along the forward / reverse direction of the resonant motion of the metamaterial basic unit, the maximum value of the tuning gap 4 is Ld, the resonant amplitude of the metamaterial basic unit is H, and Ld≤3×H. Preferably, 0.3×H≤Ld≤1.2×H.

[0093] Furthermore, in the metamaterial basic unit of this embodiment, the elastic element 1 and the main mass element 2 are both cylinders, the mounting hole 5 is a through hole, the auxiliary mass element 3 is passed through the hole, and both ends extend outward, and the anti-detachment part 31 is detachably connected to both ends of the auxiliary mass element 3.

[0094] Further, Figure 6 The schematic diagram shows the structure of the metamaterial basic unit of this embodiment applied to the base structure as a plate to form a vibration reduction and noise reduction superstructure. Figure 10 The schematic diagram shows the structure of the metamaterial basic unit of this embodiment applied to a hollow cylinder as the base structure to form a vibration-reducing and noise-reducing superstructure.

[0095] Example 3

[0096] Figure 4 The figure shows a second embodiment of the metamaterial basic unit of the present invention. In the metamaterial basic unit of this embodiment, the elastic element 1 and the main mass element 2 are both rectangular parallelepipeds, the mounting hole 5 is a stepped hole with a small entrance and a large inside, one end of the auxiliary mass element 3 is arranged in the stepped hole, and the other end extends outside the stepped hole, and the anti-detachment part 31 is arranged on the extended end.

[0097] Further, Figure 7 The schematic diagram shows the structure of the metamaterial basic unit of this embodiment applied to the base structure as a plate to form a vibration reduction and noise reduction superstructure. Figure 9 This diagram shows the structure of a metamaterial unit in this embodiment, applied to a larger plate as the base structure, to form a vibration-reducing and noise-reducing metastructure. It should be noted that the illustrated metamaterial unit should have a baffle in front to prevent it from falling out during vibration. The baffle is hidden in the figure to facilitate viewing of the internal structure.

[0098] Example 4

[0099] Figure 5 The third embodiment of the metamaterial basic unit of the present invention is shown. In the metamaterial basic unit of this embodiment, the elastic element 1 is a spring, the main mass element 2 is a cylinder, the mounting hole 5 is a threaded hole, and the anti-slip portion 31 is an external thread that cooperates with the threaded hole.

[0100] Further, Figure 8 The schematic diagram shows the structure of the metamaterial basic unit of this embodiment applied to the base structure as a plate to form a vibration-reducing and noise-reducing superstructure.

[0101] Of course, in other embodiments, the elastic element 1 may also be in other shapes, and the main mass element 2 may also be in a rhombus, a hexagonal honeycomb, a sphere, or other shapes, which are not exhaustive here.

[0102] Although the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, utilize the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for designing a superstructure for vibration and noise reduction, characterized by: The steps include: S1. Obtain basic parameters and design input information of the infrastructure; S2. Calculate the original wave dynamic characteristics of the foundation structure based on the basic parameters of the foundation structure and the design input information to obtain the basic wave shape of the foundation structure; S3. Introducing the additional mass cost of the vibration and noise reduction superstructure as a constraint condition, updating the wave dynamic characteristics of the calculation base structure, and obtaining multiple weak frequency points of acoustic vibration; S4. Conduct structural design of metamaterial basic units; S5. Generating a vibration response morphology diagram, an acoustic radiation response cloud diagram, and a sound insulation particle cloud diagram based on multiple acoustic vibration weak frequency points of the foundation structure, and performing layout design on the metamaterial basic unit to form a vibration and noise reduction superstructure; S6. Calculate the wave dynamic characteristics of the vibration and noise reduction superstructure and compare them with the target design indicators A and B. Target A refers to the target frequency range, and target B refers to the vibration reduction value, sound radiation suppression value, and sound insulation value within this range. If neither target A nor target B is met, return to step S4. If target A is met but target B is not met, return to step S5 until both target A and target B are met.

2. The vibration and noise reduction superstructure design method according to claim 1, characterized in that: The step S4 includes M1, initially set the resonant mass of the metamaterial basic unit to Mr0, and set the resonant frequency of the metamaterial basic unit to the first acoustic vibration weak frequency fr0; M2, so that Mr0 and fr0 satisfy the resonant stiffness kr0 of the basic unit of the metamaterial, (2×π×fr0) 2 ×Mr0= kr0; M3, the resonant mass of the main mass primitive (2) is assigned as Mr01, and the resonant mass of the auxiliary mass primitive (3) is assigned as Mr02, Mr01+Mr02= Mr0; M4. Material selection and determination of the geometric dimensions of the main mass primitive (2) and the auxiliary mass primitive (3); M5. Based on the geometric dimensions of the main mass element (2) and the auxiliary mass element (3), the geometric dimensions of the elastic element (1) are reversely designed, and the tuning gap (4) is determined so that the resonant frequency of the metamaterial basic unit is equal to fr0.

3. The vibration and noise reduction superstructure design method according to claim 1, characterized in that: The step S5 includes N1. Calculate the number of metamaterial basic units Nr that need to be set, Nr = Mmax / Mr0, where Mmax is the additional mass limit and Mr0 is the resonant mass of the metamaterial basic unit; N2. Draw the vibration response morphology diagram, sound radiation response cloud diagram and sound insulation particle cloud diagram of the foundation structure at each weak frequency point of acoustic vibration, and discretely arrange Nr points at the position with the largest response in these diagrams; N3. Arrange the basic units of the metamaterial at discrete points.

4. The vibration and noise reduction superstructure design method according to any one of claims 1 to 3, characterized in that: The basic parameters of the infrastructure in step S1 include: the material, configuration and size of the infrastructure; the design input information includes the target frequency range, target vibration reduction value, target sound radiation suppression value, target sound insulation value, added mass limit Mmax, boundary conditions and maximum size.

5. The vibration and noise reduction superstructure design method according to any one of claims 1 to 3, characterized in that: The wave dynamics characteristics include vibration response characteristics, sound radiation response characteristics and sound insulation characteristics.

6. The vibration and noise reduction superstructure design method according to any one of claims 1 to 3, characterized in that: The base structure may be a plate or a beam or a rod or a cylinder or a shell.

7. A metamaterial basic unit device, characterized by: A vibration and noise reduction superstructure design method for realizing any one of claims 1 to 6, comprising an elastic primitive (1), a main mass primitive (2), an auxiliary mass primitive (3) and a tuning gap (4); The elastic element (1) is used to provide resonant stiffness and support the main mass element (2) and the auxiliary mass element (3); The main mass primitive (2) is used to provide a resonant main mass; The auxiliary mass primitive (3) is used to provide a resonant auxiliary mass; The tuning gap (4) is used to provide a vibration reduction activity space for the auxiliary mass element (3); The main mass element (2) is arranged on the elastic element (1), a mounting hole (5) is provided on the main mass element (2), the auxiliary mass element (3) is installed in the mounting hole (5), the tuning gap (4) is located between the auxiliary mass element (3) and the hole wall of the mounting hole (5), and the auxiliary mass element (3) is provided with an anti-slip portion (31) for preventing the auxiliary mass element (3) from slipping out of the mounting hole (5).

8. The metamaterial basic unit device according to claim 7, characterized in that: Along the forward / reverse direction of the resonant motion of the metamaterial basic unit, the maximum value of the tuning gap (4) is recorded as Ld, and the resonant amplitude of the metamaterial basic unit is recorded as H, Ld≤3×H.

9. The metamaterial basic unit device according to claim 7, characterized in that: The elastic primitive (1) is a spring, a solid or hollow cylinder, a prism, or a special-shaped structure with elasticity, and the main mass primitive (2) is a cylinder, a rhombus, a hexagonal honeycomb, or a sphere.

10. The metamaterial basic unit device according to claim 7, characterized in that: The mounting hole (5) is a through hole, the auxiliary mass element (3) is inserted into the hole, and both ends extend outward, and the anti-slip portion (31) is detachably connected to both ends of the auxiliary mass element (3); or the mounting hole (5) is a stepped hole with a small entrance and a large interior, one end of the auxiliary mass element (3) is arranged in the stepped hole, and the other end extends out of the stepped hole, and the anti-slip portion (31) is arranged on the extended end; or the mounting hole (5) is a threaded hole, and the anti-slip portion (31) is an external thread that matches the threaded hole.

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