A method and device for regulating zero-order horizontal shear waves and application thereof

Abstract

The application provides a zero-order horizontal shear wave control method and device and application thereof, and relates to the technical field of metamaterials, and comprises the following steps: based on the anti-resonance principle, a single superstructure unit and a plate structure are divided into unit cells, an equivalent mass is constructed by dividing the unit cells, and a spring mass system is formed; based on Newton's law of motion, a simple harmonic excitation force is applied to the spring mass system, a mass motion control equation is established, the mass motion control equation is solved through an anti-resonance mechanism, and an anti-resonance geometric configuration is obtained; according to the shear deformation characteristics of the zero-order horizontal shear wave, the anti-resonance geometric configuration is derived by combining a cylindrical approximation method and a preset anti-resonance boundary condition, and a superstructure unit geometric parameter scheme is obtained; and based on the optimal size superstructure unit in the superstructure unit geometric parameter scheme, the propagation of the zero-order horizontal shear wave is controlled through superstructure units in different arrangement modes. The application solves the problem that the zero-order horizontal shear wave cannot be accurately and non-destructively controlled effectively.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metamaterials, in particular to a method and device for regulating zero-order horizontal shear wave and application thereof. BACKGROUND

[0002] In the existing metamaterial technology, for plate shell structures, zero-order horizontal shear wave (SH0 wave) is considered as one of the most potential ideal wave modes for realizing large-scale structure rapid detection and health monitoring due to its unique attribute of complete non-dispersion. In engineering applications, due to the complexity of the detection object, when the guided wave interacts with the defect, it will produce a reflected echo, and the non-defect scatterers in the structure member will also cause complex scattering and mode conversion effects, which will significantly reduce the signal-to-noise ratio of the detection signal. Therefore, it is necessary to regulate the propagation of guided waves to concentrate the energy of guided waves and suppress the complex scattering caused by scatterers. Regulating wave propagation can be understood as changing the transmission path or mode of wave energy, so as to realize an unusual wave phenomenon. Metamaterials, as a kind of artificial periodic structure, have the characteristics of flexible unit design, breaking through the response limit of traditional materials and rich wave regulation, and are therefore regarded as an effective means for regulating wave propagation. The metamaterials currently used to regulate zero-order horizontal shear wave will damage the member itself by punching and slotting, etc. Therefore, it is difficult to accurately and non-destructively control the zero-order horizontal shear wave.

[0003] Therefore, there is an urgent need for a method and device for regulating zero-order horizontal shear wave and application thereof to solve the problem of being unable to accurately and non-destructively control the zero-order horizontal shear wave. SUMMARY

[0004] The present application aims to provide a method and device for regulating zero-order horizontal shear wave and application thereof to improve the above problems. In order to achieve the above purpose, the technical solutions adopted by the present application are as follows:

[0005] In a first aspect, the present application provides a method for regulating zero-order horizontal shear wave, comprising:

[0006] Obtaining a single super-structure element and a plate structure.

[0007] Based on the anti-resonance principle, the single super-structure element and the plate structure are divided into unit cells, and a spring-mass system is formed by constructing the equivalent mass of the divided unit cells;

[0008] Based on Newton's law of motion, a simple harmonic excitation force is applied to the spring-mass system to establish a mass motion control equation, and the mass motion control equation is solved through an anti-resonance mechanism to obtain an anti-resonance geometric configuration;

[0009] According to the shear deformation characteristics of the zero-order horizontal shear wave, the anti-resonance geometric configuration is derived in combination with the cylindrical approximation method and a preset anti-resonance boundary condition, and a super-element geometric parameter scheme is obtained.

[0010] Based on the optimal size super-element in the super-element geometric parameter scheme, the propagation of the zero-order horizontal shear wave is regulated through super-elements in different arrangement modes.

[0011] In a second aspect, the application further provides a zero-order horizontal shear wave regulating device, comprising:

[0012] An acquisition module is configured to acquire a single super-element and a plate structure.

[0013] A division module is configured to divide the single super-element and the plate structure into unit cells based on the anti-resonance principle, to form a spring-mass system by constructing an equivalent mass for the divided unit cells, and to establish a mass motion control equation.

[0014] An establishment module is configured to apply a simple harmonic excitation force to the spring-mass system based on Newton's law of motion, to establish a mass motion control equation, and to solve the mass motion control equation through an anti-resonance mechanism to obtain an anti-resonance geometric configuration.

[0015] A derivation module is configured to derive the anti-resonance geometric configuration according to the shear deformation characteristics of the zero-order horizontal shear wave, in combination with the cylindrical approximation method and a preset anti-resonance boundary condition, to obtain a super-element geometric parameter scheme.

[0016] A regulation module is configured to regulate the propagation of the zero-order horizontal shear wave through super-elements in different arrangement modes based on the optimal size super-element in the super-element geometric parameter scheme.

[0017] In a third aspect, the application further provides a zero-order horizontal shear wave application method, comprising:

[0018] Based on a super-element geometric parameter scheme and the shape of a structure plate to be detected, super-elements in different arrangement modes are set and intervals are reserved to form a waveguide, and a waveguide structure is obtained.

[0019] According to the waveguide structure, the zero-order horizontal shear wave is arranged to propagate along a preset detection target, and a propagation direction is determined.

[0020] An excitation transducer is installed at the starting end of the waveguide, and a receiving transducer is installed at the end.

[0021] Based on the propagation direction, the zero-order horizontal shear wave is emitted by the excitation transducer for non-destructive testing, and when the zero-order horizontal shear wave encounters a detection defect, a reflected wave or a transmitted wave is attenuated, and the receiving transducer collects the reflected wave or the transmitted wave signal to obtain a defect detection result.

[0022] The beneficial effects of the present application are:

[0023] The present application divides the super-structure unit and the plate structure by the anti-resonance principle, and forms a spring mass system through the equivalent mass construction, and realizes the effective isolation of the zero-order horizontal shear wave based on the system using the anti-resonance principle, and on this basis, the anti-resonance geometric configuration is solved by combining Newton's law of motion and the anti-resonance mechanism, so as to accurately determine the geometric parameters of the super-structure unit and improve the design accuracy of the metamaterial. Further, according to the shear deformation characteristics of the zero-order horizontal shear wave, the anti-resonance geometric configuration is derived by combining the cylindrical approximation method and the preset anti-resonance boundary condition, and the geometric parameter scheme of the super-structure unit is obtained. The scheme makes the metamaterial exhibit excellent mechanical properties at a specific frequency, and in addition, the propagation of the zero-order horizontal shear wave is regulated based on different arrangement modes of the super-structure unit in the geometric parameter scheme of the super-structure unit, so as to realize flexible control of the wave propagation characteristics. In summary, the present application solves the problem of being unable to accurately and non-destructively control the zero-order horizontal shear wave.

[0024] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application as set forth in the claims and appended description. The purposes and other advantages of the present application can be realized and attained by the structure particularly pointed out in the written description and claims, and the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0026] Figure 1 The flow chart of the zero-order horizontal shear wave regulation method described in the embodiments of the present application;

[0027] Figure 2 The simulation results of the influence of the super-structure unit spacing and height on the wave transmittance described in the embodiments of the present application;

[0028] Figure 3 The bandwidth calculation of the super-structure unit designed at 50kHz described in the embodiments of the present application;

[0029] Figure 4 The 50kHz super-structure unit wave isolation and waveguide simulation described in the embodiments of the present application;

[0030] Figure 5A finite element calculation model for simulation of the detection of the oblique crack assisted by the super-structure unit described in the embodiment of the present application;

[0031] Figure 6 A change relationship of the reflection echo amplitude with the oblique crack angle described in the embodiment of the present application;

[0032] Figure 7 An experimental model for experimental verification of the detection of the oblique crack assisted by the super-structure unit described in the embodiment of the present application;

[0033] Figure 8 Signals measured at different frequencies without the super-structure unit in the experimental verification of the detection of the oblique crack assisted by the super-structure unit described in the embodiment of the present application;

[0034] Figure 9 Signals with the super-structure unit in the experimental verification of the detection of the oblique crack assisted by the super-structure unit described in the embodiment of the present application;

[0035] Figure 10 An experimental model for experimental verification of the detection of the zero-order horizontal shear wave assisted by the super-structure unit described in the embodiment of the present application;

[0036] Figure 11 Detection signals in the experimental verification of the detection of the zero-order horizontal shear wave assisted by the super-structure unit described in the embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions, and superiorities of the embodiments of the present application clearer, the following will be a clear and complete description of the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without creative work based on the embodiments in the present application are within the scope of protection of the present application.

[0038] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. Meanwhile, in the description of the present application, the terms “first”, “second”, and the like are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.

[0039] Embodiment 1:

[0040] The embodiment provides a method for regulating zero-order horizontal shear waves.

[0041] See Figure 1 The figure shows that the method includes steps S1 to S5, including:

[0042] S1: Obtain a single meta-element and plate structure;

[0043] In this step, the meta-elemental structure is a cuboid, which is arranged on the surface of the plate structure to block the propagation of zero-order horizontal shear waves.

[0044] S2: Based on the principle of anti-resonance, the individual superstructure and the plate structure are divided into unit cells. By constructing equivalent mass of the divided unit cells, a spring mass system is formed.

[0045] To clarify the specific method for obtaining the spring mass system, step S2 includes S21 to S23, specifically:

[0046] S21: Based on the anti-resonance principle, the individual superstructure and the plate structure are divided into unit cells to obtain a single unit cell;

[0047] In this step, the superstructure and the plate structure are theoretically analyzed based on the anti-resonance principle. Based on the theoretical analysis results, the superstructure and the plate structure are divided to obtain a single unit cell, which includes an upper superstructure and three identical lower plates.

[0048] The lower plate includes a first plate, a second plate, and a third plate. The first plate represents the incident wave, the third plate represents the wave transmission region, and the second plate represents the region directly below the corresponding meta-element.

[0049] S22: Perform equivalent mass modeling on the unit cells respectively to obtain the equivalent mass of the superstructure and the equivalent mass of the plate structure;

[0050] In this step, the unit cells are interconnected by spring units.

[0051] S23: Based on the connection stiffness characteristics of the plate structure and the superstructure, a harmonic force is applied to the equivalent mass of the superstructure and the equivalent mass of the plate structure to simulate an incident zero-order horizontal shear wave, forming a spring-mass system.

[0052] In this step, the equivalent mass of the superstructure is The equivalent mass of the plate structure is , and By assessing the equivalent mass of the plate structure A harmonic force is applied to simulate an incident zero-order horizontal shear wave, forming a spring-mass system.

[0053] S3: Apply a simple harmonic excitation force to the spring-mass system based on Newton's laws of motion, establish the mass motion control equation, and solve the mass motion control equation through the anti-resonance mechanism to obtain the anti-resonance geometric configuration;

[0054] This step is used to accurately determine the geometric parameters of metamaterial building blocks, thereby improving the design accuracy of metamaterials.

[0055] To clarify the specific method for obtaining the anti-resonance geometry, step S3 includes S31 to S34, specifically:

[0056] S31: Model the spring-mass system based on Newton's laws of motion, and perform mass element displacement on the equivalent mass of the plate structure in the spring-mass system through simple harmonic excitation force to obtain the mass motion control equation;

[0057] In this step, the gravitational influence of the spring-mass system is ignored, and the system is constrained to operate only in the horizontal direction. (Direction) movement.

[0058] In this step, the expression for the external excitation harmonic force is:

[0059] (1);

[0060] In the above formula (1), For external excitation simple harmonic force, The amplitude of the externally excited harmonic force, Angular frequency, It is a time variable;

[0061] The mass motion control equation is:

[0062] (2);

[0063] In the above formula (2), , and The equivalent mass of the plate structure. , , and respectively mass , , and acceleration, For connection and The equivalent spring stiffness coefficient, For connection and The equivalent spring stiffness coefficient, For connection and The equivalent spring stiffness coefficient, For quality displacement coordinates, For quality displacement coordinates, For quality displacement coordinates, For quality acceleration, For external excitation simple harmonic force, The equivalent lumped mass of the superstructure.

[0064] Among them, due to the equivalent mass of the plate structure , and Same, therefore = = = , = = .make = , = .

[0065] S32: Perform a Laplace transform on the mass motion control equation to obtain the frequency domain response equation;

[0066] In this step, based on Laplace's principle, that is... and .

[0067] The frequency domain response equation is:

[0068] (3);

[0069] In the above formula (3), This is the equivalent spring stiffness coefficient. The concentrated mass is the equivalent mass of the plate structure. For the complex frequency variable in the Laplace transform domain, For connection quality and The equivalent spring stiffness coefficient, The equivalent lumped mass of the superstructure unit. , , and To be respectively mass , , and Displacement response in the Laplace domain The amplitude of the externally excited harmonic force, , and The equivalent mass of the plate structure.

[0070] S33: Solve the frequency domain response equation according to the incident wave isolation principle to obtain the incident wave expression;

[0071] In this step, according to Laplace's principle, where .

[0072] The coefficients related to the system parameters are:

[0073] (4);

[0074] In the above formula (4), The coefficients are related to the system parameters. This is the equivalent spring stiffness coefficient. The concentrated mass is the equivalent mass of the plate structure. For connection quality and The equivalent spring stiffness coefficient, The equivalent lumped mass of the superstructure unit. Angular frequency;

[0075] The mass The auxiliary variables are:

[0076] (5);

[0077] In the above formula (5), For quality Auxiliary variables, For externally excited simple harmonic forces, This is the equivalent spring stiffness coefficient. The concentrated mass is the equivalent mass of the plate structure. Angular frequency, These are coefficients related to system parameters;

[0078] The mass The auxiliary variables are:

[0079] (6);

[0080] In the above formula (6), For quality Auxiliary variables, For quality displacement response, For externally excited simple harmonic forces, This is the equivalent spring stiffness coefficient. The concentrated mass is the equivalent mass of the plate structure. Angular frequency;

[0081] The mass The auxiliary variables are:

[0082] (7);

[0083] In the above formula (7), For quality Auxiliary variables, For quality displacement response, For connection quality and The equivalent spring stiffness coefficient, The equivalent lumped mass of the superstructure unit. ω is the angular frequency.

[0084] S34: The incident wave expression is analyzed based on the anti-resonance mechanism to obtain the anti-resonance geometric configuration.

[0085] In this step, the isolation of the incident wave indicates the mass unit. The response is zero when ,get It is important to note that It is a unit Its natural frequency. Additionally, when ,but It is zero. This indicates that... and Anti-resonance occurred between them, which was used to prevent waves from... spread to .

[0086] The mass The displacement response is:

[0087] (8);

[0088] In the above formula (8), For the solved mass displacement response, For externally excited simple harmonic forces, This is the equivalent spring stiffness coefficient. The concentrated mass is the equivalent mass of the plate structure. Angular frequency, For connection quality and The equivalent spring stiffness coefficient, The equivalent lumped mass of the superstructure.

[0089] S4: Based on the shear deformation characteristics of the zero-order horizontal shear wave, the anti-resonance geometric configuration is derived by combining the cylindrical approximation method and the preset anti-resonance boundary conditions, and the superstructure basic geometric parameter scheme is obtained.

[0090] In this step, the metamaterial's geometric parameter scheme is used to enable the metamaterial to exhibit excellent mechanical properties at a specific frequency.

[0091] To clarify the specific method for obtaining the geometric parameter scheme of the superstructure, step S4 includes S41 to S45, specifically:

[0092] S41: Based on the shear deformation characteristics of the zero-order horizontal shear wave, a square is selected as the cross section of the superstructure, and the shape of the superstructure is determined.

[0093] S42: Based on the wavelength of the zero-order horizontal shear wave in the structural plate, the cross-sectional side length of the superstructure shape is set, and the superstructure size is obtained by combining the cylindrical approximation method and the preset anti-resonance boundary conditions.

[0094] To clarify the specific method for obtaining the size of the meta-element, step S42 includes S421 to S424, specifically:

[0095] S421: Set the cross-sectional side length of the superstructure shape according to the wavelength of the zero-order horizontal shear wave in the plate to obtain the cross-sectional width of the superstructure.

[0096] In this step, the resonant response of the superstructure is enhanced based on the wavelength of the zero-order horizontal shear wave in the plate. The cross-sectional side length of the superstructure is set to half the wavelength of the zero-order horizontal shear wave in the plate, thus obtaining the cross-sectional width of the superstructure.

[0097] S422: Under the excitation of the zero-order horizontal shear wave, the superstructure undergoes torsional deformation, forming a shear warping effect;

[0098] S423: Based on the cylindrical approximation method and anti-resonance boundary conditions, the superstructure under the shear warping effect is simplified and analyzed. The height of the superstructure is obtained by combining the cylindrical torsion equation.

[0099] like Figure 2 As shown, a simplified analysis of the superstructure under the shear warping effect is performed, and the square column is approximated as a cylinder. The height of the superstructure is determined by analyzing the torsional anti-resonance of the cylinder.

[0100] When the unit cell exhibits anti-resonance, the unit Remaining stationary indicates that the angular displacement of the superstructure matrix region is zero. Furthermore, the cylinder is subjected to torque. The function of this. The standard equation for cylindrical torsion is:

[0101] (9);

[0102] In the above formula (9), For partial derivatives, The angle of twist of the cylinder. This represents the position of the cylinder along its length. For time variables, The speed at which a wave propagates in a medium. The mass per unit volume of the material. The ability of a material to resist shear deformation;

[0103] At the excitation end of the cylinder, specific boundary conditions must be met:

[0104] (10);

[0105] In the above formula (10), The ability of a material to resist shear deformation, For angle Regarding spatial coordinates The partial derivatives, Let be the angle of torsion of the cylinder. Let be the position coordinates of the cylinder along its length. This represents the position of the cylinder along its length. It is the polar moment of inertia. Angular frequency, The speed at which a wave propagates in a medium. It is a constant. For the amplitude of the excitation force, It is a time variable;

[0106] Substituting equation (9) into equation (10) yields:

[0107] (11);

[0108] In the above formula (11), It is a constant. For the amplitude of the excitation force, The speed at which a wave propagates in a medium. Angular frequency, For time variables, The ability of a material to resist shear deformation, It is the polar moment of inertia. The height of the cylinder;

[0109] On the other hand, the anti-resonance condition for a cylinder is that the angular displacement at the excitation end is zero, that is:

[0110] (12);

[0111] In the above formula (12), Let be the angle of torsion of the cylinder. It is a constant. Angular frequency, It is a time variable;

[0112] To meet the above conditions, It must be zero, therefore:

[0113] (13);

[0114] In the above formula (13), Angular frequency, Let be the height of the cylinder. The speed at which a wave propagates in a medium. It is infinite;

[0115] therefore:

[0116] (14);

[0117] In the above formula (14), Angular frequency, Let be the height of the cylinder. Pi It is an integer. The speed at which a wave propagates in a medium;

[0118] Right now:

[0119] (15);

[0120] In the above formula (15), Let be the height of the cylinder. It is an integer. Pi The speed at which a wave propagates in a medium. Angular frequency, λ is the wavelength.

[0121] when The minimum height of the anti-resonance cylinder can be obtained:

[0122] (16);

[0123] In the above formula (16), The height of the cylinder Wavelength;

[0124] Finally, the height of the superstructure was determined to be l / 4.

[0125] S424: The super-module dimensions are obtained by constructing based on the width and height of the super-module cross-section.

[0126] Preferably, the cross-sectional width of the meta-element is / 2, the height of the superstructure cross-section is / 4.

[0127] S43: Perform structural model analysis on a single meta-element based on finite element simulation, and determine the spacing parameters of the meta-element through the finite element simulation results;

[0128] To clarify the specific method for obtaining the meta-element spacing parameter, step S43 includes S431 to S433, specifically:

[0129] S431: Based on finite element simulation, a one-dimensional periodic arrangement of multiple superstructure elements is performed to obtain a superstructure. By setting excitation sources and receiving points for the superstructure, the finite element simulation results are obtained.

[0130] S432: Analyze the relationship between the spacing of the meta-element and the wave transmittance based on the finite element simulation results, and obtain the quantitative relationship curve between the spacing and the wave transmittance.

[0131] S433: Based on the quantitative relationship curve between the spacing and wave transmittance, determine the spacing between each meta-unit in the metastructure to obtain the meta-unit spacing parameter.

[0132] like Figure 3 As shown, when the height reaches 15.5 mm, the wave transmittance approaches zero, and this is applicable to intervals in the range of 0-30 mm. At this time, the wavelength of the zero-order horizontal shear wave in the plate structure is 62 mm, and the spacing parameter of the meta-element is less than or equal to half the wavelength, which is used to achieve wave isolation of the zero-order horizontal shear wave.

[0133] S44: Evaluate the wave isolation and waveguide performance of the superstructure at the specified dimensions based on the finite element simulation results, and determine the operating bandwidth of the superstructure.

[0134] like Figure 4 As shown, in this step, finite element simulation software was used to simulate the transmission of zero-order horizontal shear waves at different frequencies. The results show that within a 20kHz range around a center frequency of 50kHz, the wave transmittance is less than 0.1, indicating that the meta-element has good wave isolation performance in this frequency range. Simultaneously, the waveguide performance was evaluated, and its operating bandwidth was determined to be 20kHz. Within this bandwidth, the wave transmittance is less than 0.1, demonstrating effective wave isolation.

[0135] S45: Based on the shape of the super-module, the size of the super-module, the spacing parameter of the super-module, and the working bandwidth of the super-module, a scheme is constructed to obtain the geometric parameter scheme of the super-module.

[0136] S5: Based on the optimal size of the superstructure in the aforementioned superstructure geometric parameter scheme, the propagation of the zero-order horizontal shear wave is controlled by superstructures arranged in different ways.

[0137] In this step, meta-elemental units are arranged in a row along a one-dimensional direction as a wave-isolating device to effectively isolate the incident zero-order horizontal shear wave. Furthermore, arranging the meta-elemental units into two rows with arbitrary paths can serve as waveguides, guiding the zero-order horizontal shear wave to propagate along a predetermined path. Based on different arrangements of the meta-elemental units within the geometric parameter scheme, the propagation of the zero-order horizontal shear wave is controlled, enabling flexible control of the wave propagation characteristics. Simulation results show that the meta-elemental units can effectively isolate and guide the propagation of the zero-order horizontal shear wave, demonstrating their excellent wave manipulation capabilities.

[0138] Example 2:

[0139] This embodiment provides a control device for zero-order horizontal shear waves, the device comprising:

[0140] The acquisition module is used to acquire individual meta-elemental units and plate structures;

[0141] The partitioning module is used to partition the individual superstructure and the plate structure into unit cells based on the anti-resonance principle, and to form a spring mass system by constructing equivalent mass from the partitioned unit cells.

[0142] A module is established to apply a simple harmonic excitation force to the spring-mass system based on Newton's laws of motion, establish the mass motion control equation, and solve the mass motion control equation through an anti-resonance mechanism to obtain the anti-resonance geometric configuration.

[0143] The derivation module is used to derive the anti-resonance geometric configuration based on the shear deformation characteristics of the zero-order horizontal shear wave, combined with the cylindrical approximation method and preset anti-resonance boundary conditions, to obtain the superstructure basic geometric parameter scheme.

[0144] To clarify the specific methods for obtaining the derivation module, the following are included:

[0145] Shape elements are used to select squares as the cross section of the superstructure based on the shear deformation characteristics of the zero-order horizontal shear wave, and to determine the shape of the superstructure.

[0146] The size unit is used to set the cross-sectional side length of the meta-element shape based on the wavelength of the zero-order horizontal shear wave in the structural plate, and to construct it by combining the cylindrical approximation method and the preset anti-resonance boundary conditions to obtain the size of the meta-element.

[0147] To clarify the specific methods for obtaining size units, the following are included:

[0148] A sub-unit is set to set the cross-sectional side length of the superstructure shape according to the wavelength of the zero-order horizontal shear wave in the plate, so as to obtain the cross-sectional width of the superstructure.

[0149] The deformable subunit is used to generate torsional deformation of the superstructure under the excitation of the zero-order horizontal shear wave, thereby forming a shear warping effect.

[0150] The first analysis sub-unit is used to perform simplified analysis of the superstructure under the shear warping effect based on the cylindrical approximation method and anti-resonance boundary conditions, and to solve the cylindrical torsion equation to obtain the height of the superstructure.

[0151] Sub-units are constructed based on the cross-sectional width and cross-sectional height of the super-unit to obtain the super-unit dimensions.

[0152] Spacing elements are used to perform structural model analysis on a single meta-element based on finite element simulation, and to determine the spacing parameters of the meta-element through the finite element simulation results.

[0153] To clarify the specific methods for obtaining the spacing units, the following are included:

[0154] The combined sub-unit is used to perform one-dimensional periodic arrangement and combination of multiple superstructure basic elements based on finite element simulation to obtain a superstructure. By setting excitation source and receiving point on the superstructure, the finite element simulation results are obtained.

[0155] The second analysis subunit is used to analyze the relationship between the spacing of the meta-element and the wave transmittance based on the finite element simulation results, and to obtain a quantitative relationship curve between the spacing and the wave transmittance.

[0156] The spacing subunit is used to determine the spacing between each meta-element in the metastructure based on the quantitative relationship curve between the spacing and wave transmittance, thereby obtaining the meta-element spacing parameter.

[0157] A bandwidth element is used to evaluate the wave isolation and waveguide performance of the superstructure element size based on the finite element simulation results, and to determine the working bandwidth of the superstructure element.

[0158] The construction unit is used to construct a scheme based on the shape of the super-primitive, the size of the super-primitive, the spacing parameter of the super-primitive, and the working bandwidth of the super-primitive, so as to obtain the geometric parameter scheme of the super-primitive.

[0159] The control module is used to control the propagation of the zero-order horizontal shear wave by using superstructures with different arrangements, based on the optimal size of the superstructure in the geometric parameter scheme.

[0160] It should be noted that the specific manner in which each module performs its operation in the apparatus described in the above embodiments has been described in detail in the embodiments of the method, and will not be elaborated here.

[0161] Example 3:

[0162] This embodiment provides a method for applying zero-order horizontal shear waves, the method including:

[0163] Based on the geometric parameter scheme of the meta-element and the shape of the structure plate to be tested, meta-elements with different arrangements are set up and reserved intervals are reserved to form a waveguide, thus obtaining a waveguide structure;

[0164] The waveguide structure is arranged along a preset detection target to guide the zero-order horizontal shear wave to propagate along a preset path and determine the propagation direction.

[0165] An excitation transducer is installed at the beginning of the waveguide, and a receiving transducer is installed at the end.

[0166] Based on the propagation direction, the zero-order horizontal shear wave is emitted by the excitation transducer for non-destructive testing. When the zero-order horizontal shear wave encounters the defect being tested, it generates a reflected wave or a transmitted wave attenuation. The receiving transducer collects the reflected wave or transmitted wave signal to obtain the defect detection result.

[0167] In this step, the non-destructive testing includes oblique crack detection and bridge deck detection. When detecting oblique cracks, the meta-element is arranged into a linear waveguide along the direction perpendicular to the crack to guide a zero-order horizontal shear wave to be incident perpendicularly on the crack. When detecting bridge decks, the meta-element is arranged into a multi-path waveguide to cover the bridge deck detection area.

[0168] like Figures 5 to 9 As shown, the non-destructive testing includes oblique crack detection and bridge deck inspection, as detailed below:

[0169] Oblique crack detection: When performing oblique crack detection, the meta-element is arranged into a linear waveguide along the direction perpendicular to the crack to guide the zero-order horizontal shear wave to be incident perpendicularly on the crack.

[0170] The specific implementation steps are as follows:

[0171] Finite Element Simulation: First, finite element simulation was used to calculate the auxiliary capability of the meta-element. The meta-element was arranged in two rows with a gap between them to form a waveguide, which guides the propagation of the zero-order horizontal shear wave and enhances the amplitude of the reflected echo after the wave interacts with the crack. In the calculation, both the meta-element blocks and the substrate were made of aluminum, with a Young's modulus of 70 GPa, a density of 2700 kg / m³, and a Poisson's ratio of 0.33. Without the meta-element, only the 90° crack reflected echo had a relatively large amplitude; the amplitudes of the reflected echo from cracks at other angles were close to zero. Conversely, after introducing the meta-element, the amplitudes of the reflected echo from cracks at all angles increased significantly, reaching a level that was clearly identifiable.

[0172] Experimental Verification: Further experimental verification was conducted to validate the effectiveness of the meta-element-assisted detection. For example... Figure 6 As shown, in the experimental setup, both the meta-element and the substrate are made of aluminum. A piezoelectric element is used to excite and receive a zero-order horizontal shear wave. The experiment uses a 45° crack as an example. Figure 7 and Figure 8 As shown, the experimentally measured signal contains four wave packets: the first is the zero-order horizontal shear wave directly incident from the excitation end; the second is the boundary reflection echo; the third is the wave received after the boundary reflection echo is reflected again at the crack; and the wave in the gray shaded area represents the crack reflection echo. Among these, Figure 7 In the diagram, (b)-(d) represent crack reflection echoes measured at different frequencies without the meta-element. It can be seen that no crack reflection echoes are observed in these cases. Conversely, when the meta-element is introduced, significant crack reflection echoes can be observed, such as... Figure 8 As shown in (e)-(g) in the figure. This experiment verifies that meta-element can effectively assist in the detection of oblique cracks and has a bandwidth of 20 kHz.

[0173] Bridge deck inspection: When performing bridge deck inspection, the meta-element is arranged into a multi-path waveguide to cover the bridge deck inspection area.

[0174] The specific implementation steps are as follows:

[0175] like Figure 10 and Figure 11 As shown, the Figure 10 To set up the experiment, introduce cracks into the plate structure. For example... Figure 11As shown, the experimentally measured signal contains three distinct wave packets: the first wave packet is a zero-order horizontal shear wave directly incident from the excitation end; the second wave packet is a boundary reflection echo; and the third wave packet is a crack reflection echo. It can be seen that although the amplitude of the crack reflection echo wave packet is weakened compared to the incident wave, it is still clearly identifiable. However, without the assistance of the meta-element, the zero-order horizontal shear wave cannot detect cracks outside its propagation range. Therefore, the above results confirm the effective role of this meta-element in assisting in expanding the detection range of the zero-order horizontal shear wave.

[0176] Space constraints make it difficult to arrange transducers and sensors, thus hindering the detection of localized areas. This paper addresses this by introducing meta-elemental structures to construct curved path waveguides, allowing zero-order horizontal shear waves to propagate along arbitrary curved paths instead of straight lines. This expands the propagation range of zero-order horizontal shear waves and provides a new method for detecting confined areas.

[0177] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0178] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for controlling a zero-order horizontal shear wave, characterized in that, include: Obtain individual meta-elemental units and plate structures; Based on the principle of anti-resonance, the individual superstructure and the plate structure are divided into unit cells. By constructing equivalent mass from the divided unit cells, a spring mass system is formed. Based on Newton's laws of motion, a simple harmonic excitation force is applied to the spring-mass system, and a mass motion control equation is established. The mass motion control equation is then solved through an anti-resonance mechanism to obtain an anti-resonance geometric configuration. Based on the shear deformation characteristics of the zero-order horizontal shear wave, the anti-resonance geometric configuration is derived by combining the cylindrical approximation method and the preset anti-resonance boundary conditions, and the superstructure basic geometric parameter scheme is obtained. The specific method for obtaining the geometric parameter scheme of the superstructure primitive includes: Based on the shear deformation characteristics of the zero-order horizontal shear wave, a square shape is selected as the cross section of the superstructure, and the shape of the superstructure is determined. Based on the wavelength of the zero-order horizontal shear wave in the structural plate, the cross-sectional side length of the superstructure shape is set, and the superstructure size is obtained by combining the cylindrical approximation method and the preset anti-resonance boundary conditions. Structural model analysis of a single superstructure element is performed based on finite element simulation, and the spacing parameters of the superstructure element are determined through the finite element simulation results. The wave isolation and waveguide performance of the superstructure at the given dimensions are evaluated based on the finite element simulation results, and the operating bandwidth of the superstructure is determined. Based on the shape of the super-module, the size of the super-module, the spacing parameters of the super-module, and the working bandwidth of the super-module, a scheme is constructed to obtain the geometric parameter scheme of the super-module; Based on the optimal size of the superstructure in the aforementioned superstructure geometric parameter scheme, the propagation of the zero-order horizontal shear wave is controlled by superstructures arranged in different ways.

2. The method for controlling the zero-order horizontal shear wave according to claim 1, characterized in that, Based on the anti-resonance principle, the individual superstructure and the plate structure are divided into unit cells. By constructing equivalent masses from the divided unit cells, a spring-mass system is formed, including: Based on the principle of anti-resonance, the individual superstructure and the plate structure are divided into unit cells to obtain a single unit cell; Equivalent mass modeling is performed on the unit cells to obtain the equivalent mass of the superstructure and the equivalent mass of the plate structure; Based on the connection stiffness characteristics of the plate structure and the superstructure, a harmonic force is applied to the equivalent mass of the superstructure and the equivalent mass of the plate structure to simulate an incident zero-order horizontal shear wave, forming a spring-mass system.

3. The method for controlling the zero-order horizontal shear wave according to claim 1, characterized in that, Based on the wavelength of the zero-order horizontal shear wave in the structural plate, the cross-sectional side length of the meta-element shape is set, and constructed using the cylindrical approximation method and preset anti-resonance boundary conditions to obtain the meta-element dimensions, including: The cross-sectional side length of the superstructure is set according to the wavelength of the zero-order horizontal shear wave in the plate to obtain the cross-sectional width of the superstructure. The superstructure undergoes torsional deformation under the excitation of the zero-order horizontal shear wave, resulting in a shear warping effect. The superstructure under the shear warping effect is simplified and analyzed based on the cylindrical approximation method and anti-resonance boundary conditions. The height of the superstructure is obtained by combining the cylindrical torsion equation. The superstructure dimensions are obtained by constructing the superstructure based on its cross-sectional width and cross-sectional height.

4. The method for controlling the zero-order horizontal shear wave according to claim 1, characterized in that, Structural model analysis of a single meta-element is performed based on finite element simulation. The spacing parameters of the meta-element are determined through the finite element simulation results, including: Based on finite element simulation, a one-dimensional periodic arrangement of multiple superstructure elements is performed to obtain a superstructure. By setting excitation sources and receiving points for the superstructure, finite element simulation results are obtained. Based on the finite element simulation results, the relationship between the spacing of the meta-element and the wave transmittance is analyzed, and a quantitative relationship curve between the spacing and the wave transmittance is obtained. Based on the quantitative relationship curve between the spacing and wave transmittance, the spacing between each meta-unit in the metastructure is determined, and the meta-unit spacing parameter is obtained.

5. A control device for a zero-order horizontal shear wave, characterized in that, include: The acquisition module is used to acquire individual meta-elemental units and plate structures; The partitioning module is used to partition the individual superstructure and the plate structure into unit cells based on the anti-resonance principle, and to form a spring mass system by constructing equivalent mass from the partitioned unit cells. A module is established to apply a simple harmonic excitation force to the spring-mass system based on Newton's laws of motion, establish the mass motion control equation, and solve the mass motion control equation through an anti-resonance mechanism to obtain the anti-resonance geometric configuration. The derivation module is used to derive the anti-resonance geometric configuration based on the shear deformation characteristics of the zero-order horizontal shear wave, combined with the cylindrical approximation method and preset anti-resonance boundary conditions, to obtain the superstructure basic geometric parameter scheme. The derivation module includes: Shape elements are used to select squares as the cross section of the superstructure based on the shear deformation characteristics of the zero-order horizontal shear wave, and to determine the shape of the superstructure. The size unit is used to set the cross-sectional side length of the meta-element shape based on the wavelength of the zero-order horizontal shear wave in the structural plate, and to construct it by combining the cylindrical approximation method and the preset anti-resonance boundary conditions to obtain the size of the meta-element. Spacing elements are used to perform structural model analysis on a single meta-element based on finite element simulation, and to determine the spacing parameters of the meta-element through the finite element simulation results. A bandwidth element is used to evaluate the wave isolation and waveguide performance of the superstructure element size based on the finite element simulation results, and to determine the working bandwidth of the superstructure element. A construction unit is used to construct a scheme based on the shape of the super-primary element, the size of the super-primary element, the spacing parameter of the super-primary element, and the working bandwidth of the super-primary element, so as to obtain a scheme of super-primary element geometric parameters. The control module is used to control the propagation of the zero-order horizontal shear wave by using superstructures with different arrangements, based on the optimal size of the superstructure in the geometric parameter scheme.

6. The control device for zero-order horizontal shear wave according to claim 5, characterized in that, The size unit includes: A sub-unit is set to set the cross-sectional side length of the superstructure shape according to the wavelength of the zero-order horizontal shear wave in the plate, so as to obtain the cross-sectional width of the superstructure. The deformable subunit is used to generate torsional deformation of the superstructure under the excitation of the zero-order horizontal shear wave, thereby forming a shear warping effect. The first analysis sub-unit is used to perform simplified analysis of the superstructure under the shear warping effect based on the cylindrical approximation method and anti-resonance boundary conditions, and to solve the cylindrical torsion equation to obtain the height of the superstructure. Sub-units are constructed based on the cross-sectional width and cross-sectional height of the super-unit to obtain the super-unit dimensions.

7. The control device for zero-order horizontal shear wave according to claim 5, characterized in that, The spacing unit includes: The combined sub-unit is used to perform one-dimensional periodic arrangement and combination of multiple superstructure basic elements based on finite element simulation to obtain a superstructure. By setting excitation source and receiving point on the superstructure, the finite element simulation results are obtained. The second analysis subunit is used to analyze the relationship between the spacing of the meta-element and the wave transmittance based on the finite element simulation results, and to obtain a quantitative relationship curve between the spacing and the wave transmittance. The spacing subunit is used to determine the spacing between each meta-element in the metastructure based on the quantitative relationship curve between the spacing and wave transmittance, thereby obtaining the meta-element spacing parameter.

8. A method for applying a zero-order horizontal shear wave, comprising using a control method for a zero-order horizontal shear wave as described in any one of claims 1-4, characterized in that, include: Based on the geometric parameter scheme of the meta-element and the shape of the structure plate to be tested, meta-elements with different arrangements are set up and reserved intervals are reserved to form a waveguide, thus obtaining a waveguide structure; The waveguide structure is arranged along a preset detection target to guide the zero-order horizontal shear wave to propagate along a preset path and determine the propagation direction. An excitation transducer is installed at the beginning of the waveguide, and a receiving transducer is installed at the end. Based on the propagation direction, the zero-order horizontal shear wave is emitted by the excitation transducer for non-destructive testing. When the zero-order horizontal shear wave encounters the defect being tested, it generates a reflected wave or a transmitted wave attenuation. The receiving transducer collects the reflected wave or transmitted wave signal to obtain the defect detection result.

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