Impact-resistant and vibration-damping and noise-reducing integrated multifunctional metamaterial structure and preparation method thereof
By designing metamaterials with curved beam structures and fractal lattice structures, the problems of large thickness and single function have been solved, achieving a combination of lightweight, high-strength impact resistance and vibration reduction, thus expanding the application range of metamaterials.
Patent Information
- Application Number
- CN202410683532.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-30
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2044-05-30
AI Technical Summary
Existing impact-resistant metamaterial structures are thick and have limited functionality, making them difficult to apply to practical engineering problems. Furthermore, they fail to effectively address vibration reduction and noise reduction requirements, thus limiting the multifunctional design and application of metamaterials.
Using a curved beam structure as the basis, a superelastic material is combined with a polygonal metal frame to construct a unit cell structure with a superdamping effect. A lattice structure is formed through a fractal structure to design a multifunctional metamaterial that integrates impact resistance, vibration reduction, and noise reduction. By utilizing the rotational buckling deformation and superdamping effect of the superelastic material, combined with the band gap property of the fractal structure, energy dispersion and absorption can be achieved.
It achieves lightweight and high-strength metamaterial design, with good impact resistance and wide-bandwidth vibration reduction and noise reduction capabilities in the mid-to-low frequency range, expanding the application scenarios of metamaterials and making them suitable for complex working conditions.
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Figure CN118669485B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the technical field of multifunctional metamaterials, in particular to an impact-resistant and vibration-reducing and noise-reducing integrated multifunctional metamaterial structure and a preparation method thereof. BACKGROUND
[0002] In view of the demand for lightweight high-strength, impact-resistant and shock-absorbing components in the fields of aerospace and transportation, the development of lightweight metamaterials with high mechanical properties and strong energy absorption characteristics has become an important research direction. Among them, energy dissipation type impact-resistant materials have the advantages of low density, low specific strength, high specific stiffness, strong designability, and good energy absorption effect, and are one of the research hotspots in the field of mechanical impact resistance.
[0003] Compared with traditional impact-resistant metamaterials, energy dissipation type metamaterials are designed by modifying the structure of existing metamaterials, thereby exceeding the original material itself in impact resistance. When the energy dissipation type metamaterial is impacted, on the one hand, the kinetic energy of the load impact is quickly transferred from one point to the entire material plane, effectively reducing the load received per unit area of the metamaterial; on the other hand, the material converts mechanical energy into internal potential energy and internal energy through its own plastic deformation, thereby achieving the purpose of absorbing impact energy. However, due to the deformation of the material after being impacted, better energy absorption effect can be achieved, so the structure is often arranged in a multi-layer array structure, resulting in a large thickness of the structure, which is difficult to apply to actual engineering problems. Moreover, most researches focus on the mechanical properties and energy absorption effect, ignoring the demand for vibration reduction and noise reduction in actual working conditions, and the single design of the idealized impact resistance limits the application of the metamaterial and does not conform to the development trend of multifunctional design of metamaterials. SUMMARY
[0004] The impact-resistant and vibration-reducing and noise-reducing integrated multifunctional metamaterial structure and the preparation method thereof provided by the present disclosure can solve the defects of current impact-resistant metamaterial structures, such as large thickness, single function, and difficulty in application to actual engineering problems.
[0005] According to a first aspect of an embodiment of the present disclosure, an impact-resistant and vibration-reducing and noise-reducing integrated multifunctional metamaterial structure preparation method is provided, which comprises:
[0006] manufacturing a super-elastic material structure, the super-elastic material structure being based on a curved beam structure;
[0007] taking the super-elastic material structure as a core and a polygonal metal frame as a boundary, a single cell structure with super-damping effect is constructed;
[0008] the single cell structure is constructed into a lattice structure in the form of a fractal structure, and the lattice structure is arranged according to a preset requirement, and a metamaterial plate is synthesized;
[0009] According to the application scene, the polygonal metal frame boundary form and the number of the metamaterial plates are adjusted to form an integrated multifunctional metamaterial structure with shock resistance, vibration reduction and noise reduction.
[0010] In one embodiment, the manufacturing the super-elastic material structure comprises:
[0011] A stiffness equivalent model of the curved beam structure is established;
[0012] The relationship between the size and the stiffness of the curved beam structure is calculated and analyzed according to the stiffness equivalent model of the curved beam structure; wherein the size includes the curved beam length, the curved beam width, the curved beam height and the number of the curved beams, and the stiffness includes the curved beam bending stiffness and the curved beam compression stiffness;
[0013] The optimal size of the super-elastic material structure is determined according to the relationship between the size and the stiffness of the curved beam structure;
[0014] The super-elastic material structure is manufactured according to the optimal size of the super-elastic material structure.
[0015] In one embodiment, the establishing the stiffness equivalent model of the curved beam structure comprises:
[0016] The equivalent stiffness and the equivalent bending of the curved beam structure are determined according to the relationship between the compression potential energy and the bending energy;
[0017] The stiffness equivalent model of the curved beam structure is established according to the equivalent stiffness and the equivalent bending of the curved beam structure.
[0018] In one embodiment, the constructing the unit cell structure with super-damping effect with the super-elastic material structure as the core and the polygonal metal frame as the boundary comprises:
[0019] The initial strain of the unit cell structure is obtained;
[0020] The characteristic frequency of the unit cell structure is calculated according to the initial strain of the unit cell structure;
[0021] The super-damping effect of the unit cell structure is obtained by adjusting the characteristic frequency of the unit cell structure.
[0022] In one embodiment, the obtaining the initial strain of the unit cell structure comprises:
[0023] The initial strain of the unit cell structure is determined according to the relationship between the outer diameter of the super-elastic material structure and the inner diameter of the polygonal metal frame; wherein the outer diameter of the super-elastic material structure is larger than the inner diameter of the polygonal metal frame.
[0024] In one embodiment, the method further comprises:
[0025] embedding the unit cell structure into the center and each vertex of the polygonal metal frame to construct the lattice structure;
[0026] stacking the lattice structure to form a multi-level lattice structure;
[0027] arraying the multi-level lattice structure in the same plane to synthesize the metamaterial plate.
[0028] In one embodiment, before the step of arraying the lattice structure according to the preset requirement to synthesize the metamaterial plate, the method comprises:
[0029] combining theoretical analysis method with finite element simulation model to evaluate the elastic wave attenuation ability and impact resistance of the lattice structure; wherein the theoretical analysis method comprises:
[0030] calculating the dynamic response of the unit cell structure under impact by the fourth-order Runge-Kutta method, and taking the decay time of impact displacement as the evaluation basis of impact energy absorption effect;
[0031] analyzing the impact acceleration of the input end and the output end of the lattice structure by numerical simulation, and taking the impact acceleration decay rate as the evaluation basis of the impact energy absorption effect of the lattice structure.
[0032] In one embodiment, the method further comprises:
[0033] applying acceleration in a sweep frequency manner on one side boundary of the metamaterial plate, and measuring acceleration on the other side boundary of the metamaterial plate;
[0034] evaluating the shock absorption and noise reduction characteristics of the metamaterial plate according to the acceleration value.
[0035] According to a second aspect of the embodiments of the present disclosure, an integrated multifunctional metamaterial structure with impact resistance and vibration and noise reduction is provided, which is prepared according to the above-mentioned preparation method.
[0036] Compared with the prior art, the present disclosure provides an anti-impact and vibration and noise reduction integrated multifunctional metamaterial structure and a preparation method thereof. By designing the curved beam structure in the unit cell structure, an ultra-elastic material structure that is easy to rotate and bend is obtained, and the impact energy is effectively limited in the rotation deformation of the metamaterial. At the same time, by changing the characteristic frequency of the unit cell structure, an ultra-damping effect is obtained to greatly improve the impact energy absorption effect of the unit cell structure. Based on the concept of fractal structure, the unit cell structure is arranged in the form of a polygonal lattice, so that each unit cell rotates in the plane when impacted, effectively dispersing the impact direction energy in the plane, and further improving the anti-impact characteristics of the metamaterial structure. In addition, the lattice structure arranged in an array has good band gap properties, and can achieve large bandwidth vibration and noise reduction in the low frequency band. Therefore, the present disclosure has the following advantages:
[0037] 1. The present disclosure is based on the buckling characteristics of the curved beam structure, and a polygonal unit cell structure that is easy to rotate and bend and has an ultra-damping effect is designed. The unit cell structure has good impact energy attenuation effect.
[0038] 2. The present disclosure uses the concept of fractal structure to design a lattice structure in an array form, which has a large bandwidth of band gap properties and an adjustable band gap range, and can achieve vibration and noise reduction in each frequency band without complex and tedious preparation process.
[0039] 3. The present disclosure uses the concept of multi-level energy absorption to improve the impact energy attenuation characteristics of the metamaterial structure, and does not need to use a multi-layer array structure to achieve good anti-impact deformation and impact energy attenuation characteristics, so it is not limited by the processing size and can be directly applied to engineering structure problems.
[0040] 4. The present disclosure has good anti-impact characteristics and large bandwidth vibration and noise reduction capability in the low frequency band, and combines the anti-impact characteristics and vibration and noise reduction characteristics of the metamaterial, realizes the multifunctional metamaterial structure design, expands the use scene of the metamaterial, and makes it suitable for most complex working conditions.
[0041] 5. The present disclosure introduces the design of ultra-elastic material on the basis of mechanical structure, greatly reduces the structure weight while ensuring high strength mechanical properties, and realizes the lightweight high-strength metamaterial design.
[0042] Based on the above reasons, the present disclosure has wide application value in the field of metamaterial design in complex working conditions such as aerospace and transportation. BRIEF DESCRIPTION OF DRAWINGS
[0043] Figure 1 The anti-impact and vibration and noise reduction integrated multifunctional metamaterial structure preparation flowchart provided by the disclosed embodiment.
[0044] Figure 2 A schematic diagram of the rigidity of the curved beam structure provided for the embodiments of the present disclosure.
[0045] Figure 3a A 3D structure schematic diagram of the polygonal cell structure provided for the embodiments of the present disclosure.
[0046] Figure 3b A 2D structure schematic diagram of the polygonal cell structure provided for the embodiments of the present disclosure.
[0047] Figure 3c An outer frame structure schematic diagram of the polygonal cell structure provided for the embodiments of the present disclosure.
[0048] Figure 3d A hyperelastic structure schematic diagram of the polygonal cell structure provided for the embodiments of the present disclosure.
[0049] Figure 3e A theoretical force schematic diagram of the curved beam structure of the polygonal cell structure provided for the embodiments of the present disclosure.
[0050] Figure 4 A schematic diagram of the change of the characteristic frequency of the cell structure with pre-strain provided for the embodiments of the present disclosure.
[0051] Figure 5 A schematic diagram of the mode corresponding to the characteristic frequency of the cell structure provided for the embodiments of the present disclosure.
[0052] Figure 6a A schematic diagram of the quadrilateral lattice structure provided for the embodiments of the present disclosure.
[0053] Figure 6b A schematic diagram of the hexagonal lattice structure provided for the embodiments of the present disclosure.
[0054] Figure 6c A schematic diagram of the multi-level hexagonal lattice structure provided for the embodiments of the present disclosure.
[0055] Figure 7 A finite element model for simulating and calculating the transmittance provided for the embodiments of the present disclosure.
[0056] Figure 8a A cell structure impact displacement diagram of the cell structure with super-damping characteristics at different characteristic frequencies provided for the embodiments of the present disclosure.
[0057] Figure 8b A cell structure impact displacement diagram of the cell structure without super-damping characteristics at different characteristic frequencies provided for the embodiments of the present disclosure.
[0058] Figure 9a A transmittance schematic diagram of the quadrilateral lattice structure provided for the embodiments of the present disclosure.
[0059] Figure 9b A schematic diagram of transmittance for a conventional metamaterial structure.
[0060] Figure 10 A schematic diagram of impact acceleration applied in impact simulation analysis provided by an embodiment of the present disclosure.
[0061] Figure 11 A schematic diagram of a lattice metamaterial structure impact simulation structure provided by an embodiment of the present disclosure.
[0062] Figure 12a A schematic diagram of a quadrilateral lattice structure impact displacement provided by an embodiment of the present disclosure.
[0063] Figure 12b A schematic diagram of a hexagonal lattice structure impact displacement provided by an embodiment of the present disclosure.
[0064] Figure 12c A schematic diagram of a quadrilateral lattice structure acceleration provided by an embodiment of the present disclosure.
[0065] Figure 12d A schematic diagram of a hexagonal lattice structure acceleration provided by an embodiment of the present disclosure.
[0066] Figure 12e A schematic diagram of a quadrilateral lattice structure impact attenuation provided by an embodiment of the present disclosure.
[0067] Figure 12f A schematic diagram of a hexagonal lattice structure impact attenuation provided by an embodiment of the present disclosure. DETAILED DESCRIPTION
[0068] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The description of the exemplary embodiments is intended to apply to various alternative forms of the exemplary embodiments. The exemplary embodiments relate to, and are merely illustrative of, the many possible specific arrangements that fulfill the objectives and hereof. Certain exemplary embodiments are described herein with reference to the accompanying drawings. However, other arrangements can be devised that are not specifically shown or described herein, and that are within the scope of the exemplary embodiments. Accordingly, although specific arrangements can have been discussed, it should be understood that many additional arrangements can be devised and that the exemplary embodiments can be implemented in a wide variety of ways.
[0069] Figure 1 A flowchart of an impact-resistant and vibration-reducing and noise-reducing integrated multifunctional metamaterial structure provided by an embodiment of the present disclosure. As shown in the figure, the method comprises: Figure 1
[0070] Step 101, making a super-elastic material structure, the super-elastic material structure being based on a curved beam structure;
[0071] In this step, a super-elastic material structure with small bending stiffness and large compressive stiffness, which is prone to rotational buckling deformation, is designed based on a curved beam structure.
[0072] In one embodiment, the manufacturing the super-elastic material structure comprises:
[0073] establishing a stiffness equivalent model of the curved beam structure, calculating and analyzing the relationship between the size and stiffness of the curved beam structure according to the stiffness equivalent model of the curved beam structure, determining the optimal size of the super-elastic material structure according to the relationship between the size and stiffness of the curved beam structure, and manufacturing the super-elastic material structure according to the optimal size of the super-elastic material structure; wherein the size includes the curved beam length, curved beam width, curved beam height and curved beam number, and the stiffness includes the curved beam bending stiffness and the curved beam compression stiffness.
[0074] In the present embodiment, the equivalent bending stiffness and the equivalent compression stiffness of the curved beam structure can be respectively expressed as:
[0075]
[0076] wherein k 弯曲 is the equivalent bending stiffness, k 压缩 is the equivalent compression stiffness, V y is the buckling deflection, V x is the compression displacement caused by the axial force, L a represents the distance between the two ends of the buckling beam after the axial force is applied, A is the cross-sectional area of the beam, B is the elastic modulus of the material, b is the beam width, h is the beam thickness, L is the horizontal length of the beam when uncompressed, and I is the cross-sectional moment of inertia.
[0077] Specifically, by the equivalent stiffness of the curved beam structure, the relationship between the structure size and the stiffness can be obtained, as shown in Figure 2 which can be selected according to the actual requirements within the appropriate parameter range.
[0078] In one embodiment, the establishing the stiffness equivalent model of the curved beam structure comprises:
[0079] determining the equivalent stiffness and the equivalent curvature of the curved beam structure according to the relationship between the compression potential energy and the bending energy; and establishing the stiffness equivalent model of the curved beam structure according to the equivalent stiffness and the equivalent curvature of the curved beam structure.
[0080] Step 102, taking the super-elastic material structure as the core and the polygonal metal frame as the boundary, a single cell structure with super-damping effect is constructed, as shown in Figures 3a-3b , the polygonal metal frame structure is as shown in Figure 3c , and the super-elastic body structure of the polygonal single cell structure is as shown in Figure 3d .
[0081] In this step, the super-elastic material is taken as the core and the polygonal metal frame is taken as the boundary to construct a unit cell structure with super-damping effect, so that the characteristic frequency of the unit cell structure is zeroed and infinite damping is obtained to absorb impact energy.
[0082] In one embodiment, the step of taking the super-elastic material structure as the core and the polygonal metal frame as the boundary to construct a unit cell structure with super-damping effect comprises:
[0083] obtaining the initial strain of the unit cell structure; calculating the characteristic frequency of the unit cell structure according to the initial strain of the unit cell structure; and obtaining the super-damping effect of the unit cell structure by adjusting the characteristic frequency of the unit cell structure.
[0084] In this embodiment, as shown in Figure 4 , the characteristic frequency of the unit cell structure is calculated by the COMSOL Multiphysics simulation platform, and the mode corresponding to the characteristic frequency is as shown in Figure 5 , the material parameters used in the simulation are:
[0085] Super-elastic material: Young's modulus 752 KPa, density 1145 kg / m 3 , Poisson's ratio 0.49;
[0086] Metal rigid structure: Young's modulus 2×108 KPa, density 7850 kg / m 3 , Poisson's ratio 0.3.
[0087] Specifically, the geometric nonlinearity and material nonlinearity are considered in the calculation, the initial strain is applied by the interference fit of the super-elastic material and the frame, and the characteristic frequency of the unit cell structure gradually approaches 0 with the increase of the initial strain, so as to obtain the super-damping effect.
[0088] In one embodiment, the step of obtaining the initial strain of the unit cell structure comprises:
[0089] determining the initial strain of the unit cell structure according to the relationship between the outer diameter of the super-elastic material structure and the inner diameter of the polygonal metal frame; wherein the outer diameter of the super-elastic material structure is greater than the inner diameter of the polygonal metal frame.
[0090] Step 103, constructing the unit cell structure into a lattice structure in the form of a fractal structure, and arranging the lattice structure according to the preset requirements to synthesize a metamaterial plate;
[0091] In this step, the unit cell structure is embedded into the vertices of the polygonal structure, for example, a quadrilateral unit cell structure can be constructed into a quadrilateral lattice structure as shown in Figure 6a , and a hexagonal unit cell structure can be constructed into a hexagonal lattice structure as shown in Figure 6bThe multi-level lattice structure can be arranged with a unit cell structure at the center of the lattice, connected with a polygon in the form of a straight beam, as shown in Figure 6c
[0092] In one embodiment, the unit cell structure is constructed into a lattice structure in the form of a fractal structure, and the lattice structure is arranged according to the preset requirements, and the metamaterial plate is synthesized, comprising:
[0093] The unit cell structure is embedded into the center and each vertex of the polygonal metal frame to construct the lattice structure; the lattice structure is stacked to form a multi-level lattice structure; and the multi-level lattice structure is arrayed in the same plane to synthesize the metamaterial plate.
[0094] In this embodiment, the lattice structure is arrayed in the plane, and the lattices are connected in the form of a straight beam, as shown in Figure 7 The structure has a band gap property, and the attenuation of elastic waves is realized.
[0095] Step 104, adjusting the polygonal metal frame boundary form and the number of metamaterial plates according to the application scene to form an integrated multifunctional metamaterial structure of shock resistance, vibration reduction and noise reduction.
[0096] In this step, the structure size can be optimized and the performance of the metamaterial can be controlled according to the actual engineering problem. Specifically, according to the performance requirements of the structure, the structure size is adjusted, the arrangement form of the unit cell structure and the lattice structure is changed, and the performance optimization of the designed metamaterial structure is realized.
[0097] The present disclosure provides an anti-impact and vibration-reducing and noise-reducing integrated multifunctional metamaterial structure and a preparation method thereof. By designing a curved beam structure in a unit cell structure, a super-elastic material structure that is prone to rotational buckling deformation is obtained, and impact energy is effectively limited in the rotational deformation of the metamaterial. At the same time, by changing the characteristic frequency of the unit cell structure, a super-damping effect is obtained to greatly improve the impact energy absorption effect of the unit cell structure. Based on the concept of fractal structure, the unit cell structure is arranged in the form of a polygonal lattice, so that each unit cell rotates in the plane when impacted, effectively dispersing the impact direction energy into the plane, and further improving the anti-impact characteristics of the metamaterial structure. In addition, the lattice structure arranged in an array has good band gap properties, and can achieve large-bandwidth vibration reduction and noise reduction in the low-frequency band. Therefore, the present disclosure has the following advantages: based on the buckling characteristics of the curved beam structure, a polygonal unit cell structure that is prone to rotational buckling and has a super-damping effect is designed, and the unit cell structure has good impact energy attenuation effect; based on the concept of fractal structure, a lattice structure arranged in an array is designed, which has a large-bandwidth band gap property and an adjustable band gap range, and can achieve vibration reduction and noise reduction in each frequency band without a complex and tedious preparation process. Based on the concept of multi-level energy absorption, the impact energy attenuation characteristics of the metamaterial structure are improved, and good anti-impact deformation and impact energy attenuation characteristics can be achieved without using a multi-layer array structure, so the present disclosure can be directly applied to engineering structure problems without being limited by the processing size. The present disclosure has good anti-impact characteristics and large-bandwidth vibration reduction and noise reduction capabilities in the low-frequency band, and combines the anti-impact characteristics and vibration reduction and noise reduction characteristics of the metamaterial, realizes a multifunctional metamaterial structure design, expands the use scenarios of the metamaterial, and makes it suitable for most complex working conditions. The present disclosure introduces the design of super-elastic materials based on mechanical structures, greatly reduces the weight of the structure while ensuring high mechanical properties, and realizes a lightweight and high-strength metamaterial design.
[0098] Based on the above reasons, the present disclosure has wide application value in the field of metamaterial design in complex working conditions such as aerospace and transportation.
[0099] Optionally, before arranging the lattice structure according to the preset requirements and synthesizing the metamaterial plate, the method comprises:
[0100] The attenuation ability and anti-impact characteristics of the lattice structure are evaluated by combining theoretical analysis and finite element simulation models. The theoretical analysis comprises: calculating the dynamic response of the unit cell structure when impacted by a fourth-order Runge-Kutta method, and taking the decay time of the velocity as the evaluation basis for the impact energy absorption effect; and analyzing the impact acceleration of the input end and the output end of the lattice structure by numerical simulation, and taking the impact acceleration decay rate as the evaluation basis for the impact energy absorption effect of the lattice structure.
[0101] In the present embodiment, the impact resistance of the unit cell structure is evaluated using theoretical analysis and finite element simulation. Specifically, the dynamic equation of the unit cell structure when subjected to an impact is established,
[0102]
[0103] where m1 is the equivalent mass of the outer frame, m2 is the equivalent mass of the super-elastic material, x1 is the displacement of the outer frame, x2 is the displacement of the super-elastic material, b1 and b2 are the dampings of the outer frame and the super-elastic material, respectively, k1 and k2 are the linear stiffnesses of the outer frame and the super-elastic material, respectively, Γ2 is the nonlinear stiffness of the super-elastic material, and ε is the ratio of the linear natural frequency in the pre-compressed state to the natural frequency in the initial linear state.
[0104] According to the impact kinetic energy theorem, the initial condition of the system is that the system is initially at rest and subjected to a sudden impact from an external structure, and the velocity at this time can be obtained from the energy equation. Specifically, the dynamic equation is calculated using the fourth-order Runge-Kutta method, and the impact displacement of the unit cell structure over time is obtained as shown in Figures 8a-8b where the unit cell structure with super-damping effect has a rapid displacement to zero when subjected to an impact, and has a strong energy absorption effect.
[0105] Optionally, before the adjusting the boundary form of the polygonal metal frame and the number of the super-material plates according to the application scenario, the method further comprises:
[0106] determining the deformation degree of the super-material plate after being subjected to an external impact; and evaluating the impact resistance of the super-material plate according to the deformation degree.
[0107] In one embodiment, the method further comprises:
[0108] applying an acceleration to one side boundary of the super-material plate in a sweep frequency manner, measuring the acceleration at the other side boundary of the super-material plate; and evaluating the shock absorption and noise reduction characteristics of the super-material plate according to the acceleration value.
[0109] In the above embodiment, the shock absorption and noise reduction characteristics of the super-material plate are evaluated by finite element simulation. Specifically, the transmittance of the super-material plate is calculated by the COMSOL Multiphysics simulation platform, the lattice is arranged in an array in a 1x3 manner to form the super-material plate, an acceleration is applied to one side of the super-material plate, a perfect matched layer is set at the external area on the other side, and the acceleration value output from the other side is measured; wherein the transmittance calculation formula is:
[0110] T = 20 log (Aout(ω)Ain(ω));
[0111] The area with transmittance lower than -30 is considered as the blocking area of elastic wave, and the vibration and noise in this frequency range will be blocked. The transmittance of the multifunctional metamaterial structure in the embodiments of the present disclosure is shown in Figure 9a The transmittance of the conventional metamaterial structure (Baravelli E, Ruzzene M. Internally resonating lattices for bandgap generation and low-frequency vibration control [J]. Journal of Sound and Vibration, 2013, 332 (25): 6562-6579.) is shown in Figure 9b According to the comparison, it can be seen that the multifunctional metamaterial structure in the embodiments of the present disclosure has the characteristics of wide frequency filtering; at the same time, an external impact force is applied to one side of the metamaterial plate, and the impact force size is shown in Figure 10 The impact displacement and impact acceleration size of the input end and the output end of the metamaterial plate are measured, as shown in Figure 11 The impact simulation results are obtained, as shown in Figures 12a-12f .
[0112] The working principle of the anti-impact and vibration and noise reduction integrated metamaterial structure of the present disclosure is as follows:
[0113] When the anti-impact and vibration and noise reduction integrated metamaterial structure is subjected to external vertical impact, the beam structure provides high strength support force to resist the deformation of the metamaterial structure, and the impact energy is transmitted to each unit cell structure of the lattice structure by the support beam. Under the action of the super-damping effect of the unit cell structure, a large amount of impact energy is dissipated, and the remaining impact energy causes the rotation buckling of the super-elastic material in the unit cell structure. The buckling consumes energy while transmitting the impact energy along the horizontal direction to the surrounding lattice, and the surrounding lattice also dissipates the impact energy in the same way. Finally, in the case of a single-layer array structure (low thickness), a good anti-impact effect is achieved, as shown in Figures 12a-12f .
[0114] When the anti-impact and vibration and noise reduction integrated multifunctional metamaterial structure is subjected to external vibration and noise, the array arrangement of the lattice will produce a structural band gap, and the super-elastic material structure can act as a resonant unit to produce a local resonance band gap. The elastic wave in the band gap range cannot pass through the structure itself, and due to the good energy absorption effect of the structure, the energy of the elastic wave propagation will also be largely absorbed, and finally a good vibration and noise reduction effect is achieved, as shown in Figure 9a .
[0115] At the same time, the quality of the super-elastic material is much lower than other materials, especially metal materials, so the combination design of the metal material and the super-elastic material realizes high strength while minimizing the mass of the super-material structure.
[0116] The present disclosure also provides an anti-impact and vibration-reducing and noise-reducing integrated multifunctional super-material structure prepared according to the preparation method described above.
[0117] Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the present disclosure disclosed here. The present disclosure is intended to cover any variations, uses or adaptive changes of the present disclosure following the general principles of the present disclosure and including common knowledge or conventional technical means in the art not disclosed by the present disclosure. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present disclosure are indicated by the following claims.
[0118] It should be understood that the present disclosure is not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.
Claims
1. A method for preparing a multifunctional metamaterial structure with integrated impact resistance, vibration reduction and noise reduction, characterized in that: The method comprises: Producing a hyperelastic material structure, wherein the hyperelastic material structure is based on a curved beam structure; A unit cell structure with super damping effect is constructed with the super elastic material structure as the core and the polygonal metal frame as the boundary; Constructing the unit cell structure into a lattice structure in the form of a fractal structure, and arranging the lattice structure according to preset requirements to synthesize a metamaterial plate; Adjust the polygonal metal frame boundary form and the number of metamaterial plates according to the application scenario to form a multifunctional metamaterial structure that integrates impact resistance, vibration reduction and noise reduction; The manufacturing of the superelastic material structure comprises: Establishing a stiffness equivalent model of the curved beam structure; Calculating and analyzing the relationship between the dimensions and stiffness of the curved beam structure according to the stiffness equivalent model of the curved beam structure; wherein the dimensions include the length, width, height, and number of curved beams, and the stiffness includes the bending stiffness and compression stiffness of the curved beam; determining the optimal size of the hyperelastic material structure according to the relationship between the size and stiffness of the curved beam structure; manufacturing the superelastic material structure according to the optimal size of the superelastic material structure; The establishing of the stiffness equivalent model of the curved beam structure comprises: Determining the equivalent stiffness and equivalent curvature of the curved beam structure according to the relationship between compression potential energy and bending energy; A stiffness equivalent model of the curved beam structure is established according to the equivalent stiffness and equivalent curvature of the curved beam structure; wherein, The equivalent bending stiffness of the curved beam structure is expressed as: ； ； in, is the equivalent bending stiffness, is the equivalent compressive stiffness, is the buckling deflection, is the compression displacement caused by the axial force, represents the distance between the two ends of the buckled beam after the axial force is applied. is the cross-sectional area of the beam, is the elastic modulus of the material, is the horizontal length of the beam when not compressed, is the moment of inertia of the section.
2. The preparation method according to claim 1, characterized in that The unit cell structure with the super elastic material structure as the core and the polygonal metal frame as the boundary to construct the super damping effect includes: Obtaining the initial strain of the unit cell structure; Calculating the characteristic frequency of the unit cell structure according to the initial strain of the unit cell structure; The super damping effect of the unit cell structure is obtained by adjusting the characteristic frequency of the unit cell structure.
3. The preparation method according to claim 2, characterized in that The obtaining of the initial strain of the unit cell structure comprises: The initial strain of the unit cell structure is determined based on the relationship between the outer diameter of the superelastic material structure and the inner diameter of the polygonal metal frame; wherein the outer diameter of the superelastic material structure is greater than the inner diameter of the polygonal metal frame.
4. The preparation method according to claim 3, characterized in that Arranging the lattice structure according to preset requirements before synthesizing the metamaterial plate, the method includes: The elastic wave attenuation capability and impact resistance of the lattice structure are evaluated by combining a theoretical analysis method with a finite element simulation model; wherein the theoretical analysis method includes: The dynamic response of the unit cell structure when subjected to impact is calculated using the fourth-order Runge-Kutta method, and the decay time of the impact displacement is used as a basis for evaluating the impact energy absorption effect; The impact accelerations at the input and output ends of the lattice structure are analyzed by numerical simulation, and the impact acceleration attenuation rate is used as a basis for evaluating the impact energy absorption effect of the lattice structure.
5. The preparation method according to claim 1, characterized in that Before adjusting the polygonal metal frame boundary form and the number of metamaterial plates according to the application scenario, the method further includes: Determining the degree of deformation of the metamaterial plate after an external impact is applied; The impact resistance of the metamaterial plate is evaluated according to the degree of deformation.
6. The preparation method according to claim 5, characterized in that The method further comprises: Applying acceleration at one side of the metamaterial plate in a frequency sweeping manner, and measuring acceleration at the other side of the metamaterial plate; The vibration and noise reduction characteristics of the metamaterial plate are evaluated according to the acceleration value.
7. A multifunctional metamaterial structure integrating impact resistance, vibration reduction and noise reduction, characterized in that: The multifunctional metamaterial structure integrating impact resistance, vibration reduction and noise reduction is prepared according to the preparation method according to any one of claims 1 to 6.
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