Elastic wave filter based on thin plate structure of ring cylindrical shell and implementation method thereof

Abstract

An elastic wave filter based on a thin plate structure of a ring cylindrical shell and an implementation method thereof, comprising: a homogeneous elastic thin plate and a resonance structure of a hollow ring cylindrical shell. The application realizes efficient filtering and frequency selective control of elastic waves by introducing a ring cylindrical shell resonance structure. The filter has the advantages of high frequency selectivity, wide bandwidth control, flexible construction and high reliability, and is suitable for signal processing and sensing fields.

Description

Technical Field

[0001] This invention relates to a technology in the field of elastic wave filters, specifically an elastic wave filter based on a toroidal cylindrical shell thin plate structure and its implementation method. Background Technology

[0002] Elastic wave filter thin plate devices have important application value in fields such as vibration signal identification and structural health monitoring. Existing periodic array thin plate structure filter devices can achieve theoretical bandgap selection, but they have problems such as complex structure, large size, and low filtering accuracy and efficiency, and cannot accurately detect vibration frequency and mode. Summary of the Invention

[0003] To address the aforementioned shortcomings of existing technologies, this invention proposes an elastic wave filter based on a hollow annular cylindrical shell thin plate structure and its implementation method. By precisely constructing the resonance of the hollow annular cylindrical shell, the elastic wave response of the homogeneous elastic thin plate is controlled within the hollow annular cylindrical shell, achieving highly sensitive and efficient elastic wave control while possessing the characteristics of a simple and compact structure, and being easy to manufacture.

[0004] This invention is achieved through the following technical solution:

[0005] This invention relates to an elastic wave filter based on a ring-shaped cylindrical shell thin plate structure, comprising: a resonant structure of a homogeneous elastic thin plate and a hollow ring-shaped cylindrical shell.

[0006] The wall thickness of the hollow annular cylindrical shell is obtained by reverse construction using the method of constructing a discrete oscillator, specifically including:

[0007] 1) The method for constructing a discrete oscillator is as follows: , , where: H p Here, f is the height of the equivalent oscillator, f is the filtering frequency, E is the elastic modulus of the material, and R is the elastic modulus of the material. t The radius of the equivalent discrete oscillator is 2R, which is the wall thickness of the hollow annular cylindrical shell. t , Let be the zero-order Bessel function, N be the number of oscillators after discretizing the hollow annular cylindrical shell into cylinders, and E be the Young's modulus of the metallic material. Let be the density of the hollow annular cylindrical shell elastic wave filter, D be the bending stiffness of the homogeneous elastic thin plate structure, and h be the thickness of the homogeneous elastic thin plate structure.

[0008] 2) Determine the constant mode control parameter φ, elastic wave filtering frequency f, and material and geometric parameters based on the constraints of the elastic wave filtering frequency, and obtain the corresponding equivalent oscillator height H. p Specifically: ,in: Let φ be the Bessel function of order φ, k0 be the wave number, and R be the radius of the hollow annular cylindrical shell.

[0009] 3) Based on the enhancement of equivalent stiffness due to the coupling effect between discrete elements after the discrete model evolves to a hollow annular cylindrical shell, the equivalent oscillator height H is corrected. p To maintain the equivalent resonant frequency constant, the height H of the equivalent oscillator around the cylinder p By scanning parameters, elastic wave bound states with real eigenfrequency and high energy density are obtained, so as to construct an optimized elastic wave filter.

[0010] The reverse construction is preferably verified by numerical simulation, that is, by establishing a corresponding elastic wave filter solid model in numerical simulation software, and verifying the arrangement radius R of the resonant cylindrical rings under specified control requirements and the modal control parameters f. sim The error between f and the filter frequency is within an acceptable range. A dual-frequency incident wave is applied to the elastic wave filter in the time domain module, and the filtering efficiency and filtering frequency of the bare plate and hollow annular cylindrical shell elastic wave filters are compared.

[0011] This invention relates to an application based on the above-mentioned elastic wave filter, which is used for thin plate vibration characteristic identification, elastic wave filtering and sensing.

[0012] Technical effect

[0013] This invention is based on a method for constructing bound states of elastic waves. It unifies the frequency, mode, thin plate geometry, and material parameters of the bound states of elastic waves into the construction method of discrete oscillators. It achieves high-quality, low-scattering local state modulation of elastic waves with specified frequencies and modes in a specified region of the thin plate through a compact and minimalist structure. Its low-scattering bound states can be used to construct elastic wave filters for thin plate structures. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention;

[0015] In the diagram: 1. Homogeneous elastic thin plate structure; 2. Hollow annular cylindrical shell;

[0016] Figure 2 for Figure 1 Top view;

[0017] In the diagram: R is the radius of the hollow annular cylindrical shell structure;

[0018] Figure 3 The numerical simulation in this embodiment shows the evolution of the quality factor of the homogeneous elastic thin plate structure and the height of the hollow annular cylindrical shell.

[0019] Figure 4 Example Figure 3 Out-of-plane displacement field of a hollow annular cylindrical shell-uniform thin plate structure with maximum quality factor;

[0020] Figure 5 The response spectra of the bare plate and the hollow annular cylindrical shell thin plate filter in the embodiments are shown. Detailed Implementation

[0021] like Figure 1 As shown in the figure, this embodiment relates to an elastic wave filter based on a ring-shaped cylindrical shell thin plate structure, including: a homogeneous elastic thin plate 1 and a hollow ring-shaped cylindrical shell 2, wherein: the hollow ring-shaped cylindrical shell 2 is centered on the center of the homogeneous elastic thin plate 1, and the radius of the hollow ring-shaped cylindrical shell is R. The vibration on the homogeneous elastic thin plate 1 is controlled by the resonance of the hollow ring-shaped cylindrical shell 2, thereby realizing elastic wave filtering in the corresponding frequency band.

[0022] The homogeneous elastic thin plate 1 is a thin plate of uniform material with a thickness of h=2 mm, a stiffness of D, and a material of 7075 aluminum alloy.

[0023] The homogeneous elastic thin plate 1 and the hollow annular cylindrical shell 2 have a Young's modulus E of 71.7 GPa. The density of the hollow annular cylindrical shell and the elastic wave filter is... kg / m 3 The Poisson's ratio is 0.3.

[0024] In this embodiment, the filter frequency f for constructing the elastic wave according to the target requirements is 5400 Hz, and the mode is quadrupole.

[0025] In this embodiment, the radius R is the radius R = 58 mm of the ring formed by the hollow annular cylindrical shell of the elastic wave filter control region, and the wall thickness 2R of the hollow annular cylindrical shell. t =6mm.

[0026] like Figure 3 As shown, H is obtained according to the constructed discrete oscillator construction method. p By scanning the height of the annular cylindrical shell in the finite element model, the quality factor of the elastic wave filter can be obtained as Ref / (2×Imf)=8405 at the discrete cylindrical shell height of H=378.5mm, which can achieve extremely high elastic energy density localization, where Ref and Imf are the real and imaginary parts of the frequency, respectively.

[0027] like Figure 4 As shown, using Figure 3 The height parameter H of the cylindrical shell at the maximum quality factor shown is 378.5 mm. Figure 3 As shown by the vertical dashed line, the out-of-plane displacement field of its eigenmodes is verified in the numerical model. As can be seen from the figure, the filtering frequency in this embodiment is f=5420Hz, with an error of less than 0.37% compared to the target frequency.

[0028] This embodiment is based on the elastic wave filtering application of the aforementioned elastic wave filter. Specifically, in aerospace or bridge monitoring, thin-plate structures (such as aircraft skin or bridge decks) are susceptible to environmental vibration interference, requiring precise extraction of damage signals in specific frequency bands. This filter can be integrated onto the surface of the thin plate, selectively filtering non-target frequency band noise to improve the signal-to-noise ratio of damage identification. The hollow annular cylindrical shell 2 is constructed according to the following parameters (R=58mm, H=378.5mm, wall thickness 2R). t =6mm) was fixed to the center of the monitoring area of ​​the homogeneous elastic thin plate 1. A double sine signal input of sin(2ptf) + sin(2pt(f+100)) was applied to the bare plate and the hollow annular cylindrical shell elastic wave filter structure, and the vibration response spectra before and after filtering were recorded. Figure 5 By comparing the spectra before and after filtering, the amplitude attenuation characteristics of the target frequency band (5400Hz±100Hz) were extracted. At the target frequency band of 5520Hz, a suppression rate of 90.6% was maintained (the bare board response amplitude was normalized to 1, and decreased to 0.084 after filtering). Figure 3 The optimized structure with H=378.5mm has a quality factor Q=8405, which is significantly higher than that of existing periodic structure filters.

[0029] This invention achieves ultra-high quality factor (Q>8000) and precise frequency band control (error <0.37%) by constructing an aperiodic hollow annular cylindrical shell. At the same time, it breaks through the size and efficiency limitations of existing filters, showing significant advantages in structural health monitoring, high-sensitivity sensing and communication systems.

[0030] Compared with existing technologies, this invention achieves broadband elastic wave filtering on a homogeneous elastic thin plate by constructing the resonant characteristics and dimensions of a hollow annular cylindrical shell and its interaction with the homogeneous elastic thin plate. This is achieved by specifying the filtering region, filtering mode, and frequency on the plate. The invention employs a discrete oscillator construction method to construct a hollow annular cylindrical shell elastic wave filter with a specified filtering region, filtering mode, and frequency, achieving a filtering efficiency of over 90%. This significantly improves the elastic wave filtering efficiency of homogeneous elastic thin plate filter devices, providing a new approach for high-precision elastic wave filtering in compact spatial thin plate devices, and possesses significant engineering application value.

[0031] The above-described specific implementations can be partially adjusted by those skilled in the art in different ways without departing from the principles and purpose of the present invention. The scope of protection of the present invention is defined by the claims and is not limited to the above-described specific implementations. All implementation schemes within the scope of the claims are bound by the present invention.

Claims

1. An application of an elastic wave filter based on a ring-shaped cylindrical shell thin-plate structure, characterized in that, The elastic wave filter is a resonant structure composed of a homogeneous elastic thin plate and a hollow annular cylindrical shell; the application refers to using the elastic wave filter for thin plate vibration characteristic identification, elastic wave filtering, and sensing. The wall thickness of the hollow annular cylindrical shell is obtained by reverse engineering using the method for constructing a discrete oscillator to obtain the radius R of the equivalent discrete oscillator. t Then, with 2R t The wall thickness of the hollow annular cylindrical shell, where the radius R of the equivalent discrete oscillator is... t Obtained through the following methods: 1) Constructing a discrete oscillator: , ,in: H p The height of the equivalent oscillator. f For filtering frequency, E The elastic modulus of the material, Let N be the zero-order Bessel function, and N be the number of oscillators after the hollow annular cylindrical shell is discretized into cylinders. The density of the hollow annular cylindrical shell elastic wave filter. D Let be the bending stiffness of the homogeneous elastic thin plate structure, and h be the thickness of the homogeneous elastic thin plate structure. Let be the order of the Bessel function, which serves as the modal control parameter. k 0 R is the wave number, and R is the radius of the hollow annular cylindrical shell, which is used as the arrangement radius. 2) Determine the modal control parameters based on the constraints of the elastic wave filter frequency. The filtering frequency f of the elastic wave and the material and geometric parameters are as follows: ,in: for Bessel function of order 1; 3) Based on the enhancement of equivalent stiffness due to the coupling effect between discrete elements after the discrete model evolves into a hollow annular cylindrical shell, the equivalent oscillator height is corrected. H p To maintain the equivalent resonant frequency constant, around the equivalent oscillator height H p By scanning parameters, we obtain elastic wave bound states with real eigenfrequency and high energy density, in order to construct an optimized elastic wave filter. The reverse construction described above is verified by substituting the model into a numerical simulation method. A corresponding elastic wave filter solid model is established in the numerical simulation software to verify the arrangement radius R of the resonant cylindrical rings for the specified control requirements, and the modal control parameters f. sim The error between f and the filter frequency is within an acceptable range. A dual-frequency incident wave is applied to the elastic wave filter in the time domain module, and the filtering efficiency and filtering frequency of the bare plate and hollow annular cylindrical shell elastic wave filters are compared.

2. The application according to claim 1, characterized in that, The homogeneous elastic thin-plate structure and the hollow annular cylindrical shell both use metallic materials with a Young's modulus E of 71.7 GPa; the density of the hollow annular cylindrical shell and the elastic wave filter are both... kg / m 3 The Poisson's ratio is 0.3 for all of them.

3. The application according to claim 2, characterized in that, The homogeneous elastic thin plate is a thin plate of uniform material with a thickness of h=2 mm and is made of 7075 aluminum alloy.

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