Structure of resonance aggregate and method for selecting resonance aggregate and optimally designing proportion of resonance aggregate

Abstract

The invention discloses a method for optimally designing and selecting a resonance aggregate and a resonance aggregate ratio by utilizing a finite element result. The method comprises the following steps: (1) setting a band gap range threshold value M and a vibration acceleration threshold value P; (2) preliminarily generating a resonance aggregate structure according to a design target; (3) inputting the generated resonant aggregate structure into finite element software, and calculating a cellular energy band structure of the multi-resonant aggregate concrete photonic crystal; (4) if the band gap range of the energy band structure of the multi-resonance aggregate concrete photonic crystal cell is larger than M, repeating the steps (2)-(4); (5) calculating the ratio; (6) establishing a multi-resonance aggregate concrete phononic crystal concrete structure according to a design target; and (7) outputting according with the matching requirement. According to the method for optimally designing and selecting the resonance aggregate and the resonance aggregate ratio by utilizing the finite element result, by virtue of the advantages of the photonic crystal metamaterial, a reasonable vibration reduction structure form is explored and constructed, the vibration of an engineering structure is effectively reduced, and the construction cost is reduced.

Description

Technical Field

[0001] The invention relates to the structure of a resonance aggregate and a method for selecting the resonance aggregate and optimizing the proportion of the resonance aggregate, belonging to the field of materials. Background Art

[0002] The vibration of engineering structures is harmful to the human body and has a serious impact on human production and life. Vibration prevention and control is a major challenge facing the engineering field. The surface waves of engineering structure vibration are the primary cause of harm to human health. When the vibration acceleration level reaches 65dB (decibel), it begins to affect people's sleep. Long-term exposure to a vibrating environment has significant harm to human physiology. It is difficult to reduce and control such low-frequency vibrations using conventional methods (such as installing sound barriers, setting vibration isolation pads, etc.). Therefore, it is imperative to develop new technologies and methods to control and reduce low-frequency surface waves.

[0003] In recent years, phononic crystal metamaterials have provided new concepts and methods for isolating and controlling these low-frequency surface waves. Phononic crystal metamaterials have unique properties that natural materials do not have, such as negative effective mass density and negative effective modulus. The most important feature of acoustic crystal metamaterials is the band gap, in which vibrations can be rapidly reduced without propagating, but the low-frequency band gap of traditional acoustic crystal metamaterials is usually single and narrow, and cannot effectively isolate vibrations. There are also a few metamaterials with wider band gaps, but their band gap frequencies are relatively high, and the vibrations of engineering structures caused by engineering structures are mainly low-frequency vibrations. Even if a small number of phononic crystal metamaterials have band gaps that can meet the requirements, their lattice constants are too large, often exceeding one meter, which leads to high costs and great construction difficulties. Summary of the invention

[0004] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a method for optimizing the design and selecting the resonant aggregate and the resonant aggregate ratio using finite element results, and explores and constructs a reasonable vibration reduction structure by taking advantage of the advantages of phononic crystal metamaterials, so as to effectively reduce the vibration of the engineering structure and reduce the construction cost.

[0005] Technical solution: In order to solve the above technical problems, a resonant aggregate structure is provided, characterized in that it includes a scatterer and a flexible wrapping layer, the density of the scatterer is greater than the density of concrete, the flexible wrapping layer is a sound-absorbing material, the flexible wrapping layer is sleeved on the scatterer, and a plurality of cavities are provided on the flexible wrapping layer.

[0006] 2. The structure of the resonant aggregate according to claim 1, characterized in that the scatterer is in the shape of a sphere, a cuboid, a cylinder or a triangular prism.

[0007] 3. The structure of the resonant aggregate according to claim 1 is characterized in that: the scatterer is in the shape of a sphere, the flexible wrapping layer is in the shape of a sphere, six wedges are cut off from the surface of the sphere of the flexible wrapping layer to form six cavities, which are evenly distributed on the surface of the sphere at intervals of 1 / 4 of the circumference of the large circle; the scatterer is in the shape of a cylinder, and the cylindrical flexible wrapping layer has four wedges cut off at the center position of the height direction of the resonant aggregate to form four cavities, which are evenly distributed on the flexible wrapping layer at intervals of 1 / 4 of the circumference of the large circle, and one wedge is cut off at the center position of each of the two bottom surfaces to form a cavity. For flexible wrapping layers of other shapes, one wedge is cut off at the center position of each surface of the flexible wrapping layer to form a cavity, which is evenly distributed on the flexible wrapping layer.

[0008] A method for optimizing the design and selecting the resonant aggregate and the resonant aggregate ratio by using finite element results comprises the following steps:

[0009] (1) Setting the band gap range threshold M and the vibration acceleration threshold P;

[0010] (2) Based on the relationship between the structure of the phononic crystal unit cell of the resonant aggregate concrete and its energy band structure, the structural parameters of the resonant aggregate are preliminarily calculated. The resonant aggregate is composed of a scatterer and a flexible wrapping layer. The parameters include the elastic modulus, Poisson's ratio, size, and density of the scatterer and the elastic modulus, Poisson's ratio, size, and density of the wrapping layer;

[0011] (3) Inputting the generated resonant aggregate structure into the finite element software, establishing a multi-resonant aggregate concrete phononic crystal cell, and calculating the band structure of the multi-resonant aggregate concrete phononic crystal cell;

[0012] (4) If the band gap range of the band structure of the multi-resonant aggregate concrete phononic crystal unit cell is greater than the band gap range threshold M, the parameters of the scatterer and the flexible wrapping layer are optimized and adjusted according to the relationship between the structure of the resonant aggregate concrete phononic crystal unit cell and its band structure, i.e., steps (3)-(4) are repeated;

[0013] (5) calculating the proportion of the resonant aggregate and the multi-resonant aggregate concrete metamaterial according to the specific relationship between the starting frequency and the cutoff frequency of the band gap;

[0014] (6) Input the resonant aggregate structure and the ratio of concrete to resonant aggregate that have been preliminarily judged into the finite element software, and establish a multi-resonant aggregate concrete phononic crystal concrete structure according to the design goal;

[0015] (7) The vibration acceleration of the phononic crystal concrete structure is calculated according to the acoustic wave propagation characteristics and the energy band structure. When the calculated result is less than the vibration acceleration threshold value P, the structural size, physical properties and proportion between the resonant aggregate and the concrete are output for use in the production of a multi-resonant concrete phononic crystal vibration reduction structure. When the calculated vibration acceleration result is greater than the vibration acceleration threshold value P, the proportion is adjusted according to the specific relationship between the starting frequency and the cutoff frequency of the resonant aggregate and the band gap of the multi-resonant aggregate concrete metamaterial cell, i.e., steps (6)-(7) are repeated.

[0016] Preferably, in the step (2), the vibration mode of the phononic crystal cell is simplified to a mass-spring system, and the relationship between the structure of the multi-resonance aggregate concrete phononic crystal cell and its energy band structure is obtained. The relationship between the structure of the multi-resonance aggregate concrete phononic crystal cell and its energy band structure is shown in the following formula:

[0017]

[0018]

[0019] Where: K is the stiffness matrix of the typical unit, M is the mass matrix, a is the lattice constant of the multi-resonant aggregate concrete metamaterial cell, m i is the mass of the i-th scatterer, r i is the radius of the i-th scatterer, R i is the outer diameter of the package layer i, E is Young's modulus, v is Poisson's ratio, k i is the equivalent stiffness of the wrapping layer, k0 is the equivalent stiffness of the matrix, ω i is the natural frequency of the scatterer, i ranges from 1 to n, and n is the number of resonant aggregates.

[0020] Preferably, in step (2), the proportion of the resonant aggregate is calculated according to the specific relationship between the starting frequency and the cutoff frequency of the band gap of the resonant aggregate and the multi-resonant aggregate concrete metamaterial cell. The specific relationship between the starting frequency and the cutoff frequency of the resonant aggregate and the multi-resonant aggregate concrete metamaterial cell band gap is as shown in the following formula:

[0021]

[0022] Where: m1 is the equivalent mass of the scatterer, m2 is the equivalent mass of the matrix, C 11 and C 44 is the elastic modulus, r i is the radius of scatterer i, R i is the outer diameter of the package layer i, E is Young's modulus, v is Poisson's ratio, k iis the equivalent stiffness of the wrapping layer, f1 is the starting frequency of the band gap of the multi-resonant aggregate concrete metamaterial cell, and f2 is the cutoff frequency of the band gap of the multi-resonant aggregate concrete metamaterial cell.

[0023] In the present invention, by uniformly adding different types of resonant aggregates into the cement mortar matrix, the resonant unit is changed from a single-degree-of-freedom system to a multi-degree-of-freedom system, so that the phononic crystal metamaterial has the characteristics of multiple local resonances, and then the vibration reduction frequencies of different targets are adapted by controlling the ratio of concrete to the resonant aggregate. The resonant aggregate inside the concrete phononic crystal metamaterial is composed of a scatterer and a flexible wrapping layer. The mass resonator formed by the resonant aggregate in the concrete phononic crystal will have a resonance effect, forming a resonant band gap near its natural frequency, effectively attenuating the propagation of stress waves in the concrete, and showing wave-absorbing and vibration-reducing performance different from that of ordinary concrete.

[0024] In the present invention, due to the different geometric dimensions and physical properties of the resonant aggregate, the resonant aggregate also has a bandgap characteristic of blocking or suppressing wave vibration. This structure forms an effective acoustic impedance interface by optimizing the arrangement of the scatterer and the material of the wrapping layer. The scatterer shape can be selected from spheres, cuboids, cylinders, triangular prisms, etc., and is made of materials with a density higher than concrete, such as metal. The flexible wrapping layer is sleeved on the scatterer, and the material of the flexible wrapping layer is selected from materials with good sound absorption and good elastic properties, such as polystyrene foam particles. The spherical flexible wrapping layer cuts off six wedges on the surface of the sphere to form six cavities, which are evenly distributed on the surface of the sphere at intervals of 1 / 4 of the circumference of the large circle. The cylindrical flexible wrapping layer cuts off four wedges at the center position of the height direction of the resonant aggregate to form four cavities, which are evenly distributed on the flexible wrapping layer at intervals of 1 / 4 of the circumference of the large circle, and a wedge is cut off at the center position of each of the two bottom surfaces to form a cavity. For flexible wrapping layers of other shapes, a wedge is cut off at the center of each surface of the flexible wrapping layer to form cavities evenly distributed on the flexible wrapping layer.

[0025] Beneficial effects: The method of optimizing the design and selecting the resonant aggregate and the resonant aggregate ratio by using the finite element results of the present invention has the following advantages:

[0026] 1. Aiming at the vibration of engineering structures, the present invention creatively proposes a method for manufacturing a concrete resonant aggregate and a vibration reduction structure for solving the low-frequency vibration of engineering vibration, which can effectively reduce noise and vibration while ensuring the bearing capacity of the structure.

[0027] 2. The present invention can be directly and evenly mixed with concrete. Compared with other vibration reduction measures, it does not require additional construction processes and steps. Therefore, it can effectively reduce construction risks and difficulties, reduce machinery and equipment costs, shorten construction periods, and greatly improve the economy and safety of the construction process. It has good use value for actual projects.

[0028] 3. This method can quickly design concrete phononic crystal cells with excellent acoustic properties, and promote the research and application of phononic crystal vibration reduction and noise reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flowchart of an embodiment of the present invention;

[0030] Figure 2 is a schematic diagram of the structure of a multi-resonance concrete phononic crystal floor according to an embodiment of the present invention;

[0031] Figure 3 is a schematic diagram of the spherical resonant aggregate structure of an embodiment of the present invention;

[0032] Figure 4 is a schematic diagram of a rectangular parallelepiped resonant aggregate structure according to an embodiment of the present invention;

[0033] Figure 5 is a schematic diagram of a cylindrical resonant aggregate structure according to an embodiment of the present invention;

[0034] Figure 6 is a schematic diagram of a triangular prism resonant aggregate structure according to an embodiment of the present invention;

[0035] Figure 7 is a diagram of the energy band structure of a concrete phononic crystal according to an embodiment of the present invention;

[0036] Figure 8 This is a 1 / 3 octave frequency diagram of a multi-resonant concrete phononic crystal floor slab according to an embodiment of the present invention;

[0037] In the figure: 1. Encapsulation layer; 2. Encapsulation layer cavity; 3. Scatterer. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings.

[0039] The present invention takes the low-frequency vibration of the engineering structure caused by rail transit as an example to establish a multi-resonance concrete phononic crystal vibration reduction and noise reduction floor. Figures 1 to 8 As shown, a method for optimizing the design and selecting the resonant aggregate and the resonant aggregate ratio by using the finite element results comprises the following steps:

[0040] (1) According to the design goal, a resonant aggregate structure is initially generated. The vibration mode of the phononic crystal cell can be simplified to a mass-spring system, and the specific relationship between the structure of the multi-resonant aggregate concrete phononic crystal cell and its band structure is obtained, so as to estimate the size of the resonant aggregate and the size of the wrapping layer cavity. The specific relationship between the structure of the multi-resonant aggregate concrete phononic crystal cell and its band structure is shown in the following formula:

[0041]

[0042] Where: K is the stiffness matrix of the typical unit, M is the mass matrix, a is the lattice constant of the multi-resonant aggregate concrete metamaterial cell, m i is the mass of scatterer i, r i is the radius of scatterer i, R i is the outer diameter of the package layer i, E is Young's modulus, v is Poisson's ratio, k i is the equivalent stiffness of the wrapping layer, k0 is the equivalent stiffness of the matrix, ω i is the natural frequency of the scatterer, i ranges from 1 to n, and n is the number of resonant aggregates.

[0043] The multi-resonance aggregate concrete phononic crystal unit cell is a hexahedron, and the scatterer is made of steel, where the physical parameters of the steel are Poisson's ratio 0.3 and density 7780Kg / m 3 , elastic modulus 2.1e 11 Pa. The scatterer shape can be a sphere, a cuboid, a cylinder or a regular triangular prism, such as Figure 3-Figure 6 , the radius r1 of the sphere is 40mm, the length l1, width l2 and height h1 of the cuboid are 32×30×28mm, the bottom radius r2 of the cylinder is 30mm, the height h2 of the cylinder is 65mm, the bottom side length l3 of the regular triangular prism is 50mm, and the height h3 of the regular triangular prism is 55mm. The flexible wrapping layer is set on the scatterer. The flexible wrapping layer in the shape of a sphere cuts off six wedges on the surface of the sphere to form six cavities, which are evenly distributed on the surface of the sphere at intervals of 1 / 4 of the circumference of the large circle. The flexible wrapping layer in the shape of a cylinder cuts off four wedges at the center position of the height direction of the resonant aggregate to form four cavities, which are evenly distributed on the flexible wrapping layer at intervals of 1 / 4 of the circumference of the large circle, and a wedge is cut off at the center position of each bottom surface to form a cavity. For flexible wrapping layers of other shapes, a wedge is cut off at the center position of each surface of the resonant aggregate to form a cavity, which is evenly distributed on the flexible wrapping layer. The material of the flexible wrapping layer is polystyrene foam particles with good sound absorption and elasticity. The physical parameters of the polystyrene foam particles are Poisson's ratio 0.13 and density 12Kg / m 3 , elastic modulus is 1.34e 5Pa. The thickness of the wrapping layer is 8mm, 6mm, 6mm, and 5mm, respectively, to ensure effective absorption of sound waves of specific frequencies.

[0044] (2) Determine whether the structure of the resonant aggregate meets the requirements. Input the generated resonant aggregate structure into the finite element software, establish a multi-resonant aggregate concrete phononic crystal cell, calculate the band structure of the multi-resonant aggregate concrete phononic crystal cell, and determine whether the band gap range of the structure meets the band gap range of the design target.

[0045] The computational model of the unit cell is established in Comsol Multiphysics software, and the mesh is divided using free tetrahedral units. According to the general finite element method steps, the shape function is determined, the stiffness matrix and mass matrix in the unit cell are established, and the Brillouin periodic boundary conditions are applied on the boundary. In Comsol Multiphysics software, the Eigenvalue solver is selected, and a set of structural eigenfrequencies can be obtained by giving a k value. As mentioned above, when the wave vector k traverses the simplified Brillouin zone boundary along the Γ-XM-Γ direction, the complete dispersion relationship between the wave vector and the natural frequency, that is, the band diagram, can be obtained.

[0046] The vibration of the engineering structure caused by rail transit is mainly concentrated below 80 Hz. Therefore, when the calculation results show that the band gap range of the energy band gap is below 80 Hz, the structure is judged to be a valid structure. When the calculation results show that the band gap range of the energy band gap exceeds 80 Hz, the structure is judged to be an invalid structure and returns to step (1). According to the relationship between the structure of the resonant aggregate concrete phononic crystal unit cell and its energy band structure, the parameters of the scatterer and the flexible wrapping layer are optimized and adjusted, and the above steps are repeated until the preliminary judgment is passed.

[0047] (3) Calculate the ratio of concrete to resonant aggregate. The ratio is calculated based on the specific relationship between the starting frequency and the cutoff frequency of the resonant aggregate and the band gap of the multi-resonant aggregate concrete metamaterial cell. The specific relationship between the starting frequency and the cutoff frequency of the resonant aggregate and the band gap of the multi-resonant aggregate concrete metamaterial cell is shown in the following formula:

[0048]

[0049]

[0050] Where: m1 is the equivalent mass of the scatterer, m2 is the equivalent mass of the matrix, C 11 and C 44 is the elastic modulus, r i is the radius of scatterer i, R i is the outer diameter of the package layer i, E is Young's modulus, v is Poisson's ratio, k iis the equivalent stiffness of the wrapping layer, f1 is the starting frequency of the band gap of the multi-resonant aggregate concrete metamaterial cell, and f2 is the cutoff frequency of the band gap of the multi-resonant aggregate concrete metamaterial cell.

[0051] The resonant aggregate structure and the ratio of concrete to resonant aggregate that have passed the preliminary judgment are input into the finite element software, and a subway tunnel-building model is established to obtain the vibration acceleration of the floor slab. According to the sound wave propagation characteristics and the energy band structure, its vibration acceleration is calculated to make a basic physical judgment. According to the standards of the Ministry of Railways of China, the limit of human vibration comfort is determined to be 67dB. When the calculation results show that the design target vibration reduction frequency is met, the structural dimensions, physical properties and the ratio of the resonant aggregate are output for the production of the multi-resonant concrete phononic crystal vibration reduction structure. When the calculation results of the finite element analysis method show that the design target vibration reduction frequency is not met, the calculation steps of the ratio of concrete to resonant aggregate are returned, and the ratio size is adjusted according to the specific relationship between the starting frequency and the cutoff frequency of the resonant aggregate and the band gap of the multi-resonant aggregate concrete metamaterial cell, that is, step (3) is repeated until the calculation results of the finite element analysis method show that the energy band structure of the new structure meets the design target vibration reduction frequency.

[0052] (4) The concrete is evenly mixed with the resonant aggregate and poured on site to form a floor structure with good vibration reduction and sound insulation performance, such as Figure 8 shown.

[0053] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A structure of a resonant aggregate, characterized in that: It includes a scatterer and a flexible wrapping layer. The density of the scatterer is greater than that of concrete. The flexible wrapping layer is a sound absorbing material. The flexible wrapping layer is sleeved on the scatterer and a plurality of cavities are arranged on the flexible wrapping layer.

2. The structure of the resonant aggregate according to claim 1, characterized in that: The scatterer is in the shape of a sphere, a cuboid, a cylinder or a triangular prism.

3. The structure of the resonant aggregate according to claim 1, characterized in that: The scatterer is in the shape of a sphere, the flexible wrapping layer is in the shape of a sphere, six wedges are cut off from the spherical surface of the flexible wrapping layer to form six cavities, which are evenly distributed on the surface of the sphere at intervals of 1 / 4 of the circumference of the largest circle; the scatterer is in the shape of a cylinder, four wedges are cut off from the cylindrical flexible wrapping layer at the center position in the height direction of the resonant aggregate to form four cavities, which are evenly distributed on the flexible wrapping layer at intervals of 1 / 4 of the circumference of the largest circle, and one wedge is cut off from the center position of each of the two bottom surfaces to form a cavity.

4. A method for optimizing the design and selecting the resonant aggregate and the resonant aggregate proportion by using finite element results according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Setting the band gap range threshold M and the vibration acceleration threshold P; (2) Based on the relationship between the structure of the phononic crystal unit cell of the resonant aggregate concrete and its energy band structure, the structural parameters of the resonant aggregate are preliminarily calculated. The resonant aggregate is composed of a scatterer and a flexible wrapping layer. The parameters include the elastic modulus, Poisson's ratio, size, and density of the scatterer and the elastic modulus, Poisson's ratio, size, and density of the wrapping layer; (3) Inputting the generated resonant aggregate structure into the finite element software, establishing a multi-resonant aggregate concrete phononic crystal cell, and calculating the band structure of the multi-resonant aggregate concrete phononic crystal cell; (4) If the band gap range of the band structure of the multi-resonant aggregate concrete phononic crystal unit cell is greater than the band gap range threshold M, the parameters of the scatterer and the flexible wrapping layer are optimized and adjusted according to the relationship between the structure of the resonant aggregate concrete phononic crystal unit cell and its band structure, i.e., steps (3)-(4) are repeated; (5) calculating the proportion of the resonant aggregate and the multi-resonant aggregate concrete metamaterial according to the specific relationship between the starting frequency and the cutoff frequency of the band gap; (6) Input the resonant aggregate structure and the ratio of concrete to resonant aggregate that have been preliminarily judged into the finite element software, and establish a multi-resonant aggregate concrete phononic crystal concrete structure according to the design goal; (7) The vibration acceleration of the phononic crystal concrete structure is calculated according to the acoustic wave propagation characteristics and the energy band structure. When the calculated result is less than the vibration acceleration threshold value P, the structural size, physical properties and proportion between the resonant aggregate and the concrete are output for use in the production of a multi-resonant concrete phononic crystal vibration reduction structure. When the calculated vibration acceleration result is greater than the vibration acceleration threshold value P, the proportion is adjusted according to the specific relationship between the starting frequency and the cutoff frequency of the resonant aggregate and the band gap of the multi-resonant aggregate concrete metamaterial cell, i.e., steps (6)-(7) are repeated.

5. The method for selecting resonant aggregate and resonant aggregate proportion by optimizing design using finite element results according to claim 4 is characterized in that: In the step (2), the vibration mode of the phononic crystal cell is simplified to a mass-spring system, and the relationship between the structure of the multi-resonance aggregate concrete phononic crystal cell and its energy band structure is obtained. The relationship between the structure of the multi-resonance aggregate concrete phononic crystal cell and its energy band structure is shown in the following formula: Where: K is the stiffness matrix of the typical unit, M is the mass matrix, a is the lattice constant of the multi-resonant aggregate concrete metamaterial cell, m i is the mass of the i-th scatterer, r i is the radius of the i-th scatterer, R i is the outer diameter of the i-th package layer, E is Young's modulus, v is Poisson's ratio, k i is the equivalent stiffness of the wrapping layer, k0 is the equivalent stiffness of the matrix, ω i is the natural frequency of the scatterer, i ranges from 1 to n, and n is the number of resonant aggregates.

6. The method for selecting resonant aggregate and resonant aggregate proportion by optimizing design using finite element results according to claim 4 is characterized in that: In the step (2), the proportion of the resonant aggregate is calculated according to the specific relationship between the starting frequency and the cutoff frequency of the band gap of the resonant aggregate and the multi-resonant aggregate concrete metamaterial cell. The specific relationship between the starting frequency and the cutoff frequency of the band gap of the resonant aggregate and the multi-resonant aggregate concrete metamaterial cell is as shown in the following formula: Where: m1 is the equivalent mass of the scatterer, m2 is the equivalent mass of the matrix, C 11 and C 44 is the elastic modulus, r i is the radius of scatterer i, R i is the outer diameter of the package layer i, E is Young's modulus, v is Poisson's ratio, k i is the equivalent stiffness of the wrapping layer, f1 is the starting frequency of the band gap of the multi-resonant aggregate concrete metamaterial cell, and f2 is the cutoff frequency of the band gap of the multi-resonant aggregate concrete metamaterial cell.

7. The method for selecting resonant aggregate and resonant aggregate proportion by optimizing design using finite element results according to claim 5 or 6, characterized in that: The scatterer is in the shape of a sphere, a cuboid, a cylinder or a triangular prism.

8. The method for selecting resonant aggregate and resonant aggregate proportion by optimizing design using finite element results according to claim 7 is characterized in that: The density of the scatterer is greater than the density of the concrete material.

9. The method for selecting resonant aggregate and resonant aggregate proportion by optimizing design using finite element results according to claim 7, characterized in that: The scatterer outer shell is provided with a flexible wrapping layer.

Images