Test panel for reflected wave attenuation based on acoustic black hole effect

Abstract

The application discloses a reflection wave weakening test board based on acoustic black hole effect, which comprises a test board body and a spiral acoustic black hole arranged at the edge of the test board body and used for weakening the reflection signal of the boundary. The application can weaken the reflection wave of the edge of the test board, and is safe and reliable in use, small in space occupation and simple in structure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of acoustic emission lead break test plate, and particularly relates to a reflected wave weakening test plate based on acoustic black hole effect. BACKGROUND

[0002] With the continuous development of acoustic emission basic theory, sensor technology and signal processing and analysis technology, the acoustic emission nondestructive testing technology is increasingly widely applied in the fields of petrochemical industry, material testing, aerospace, electronic industry and medicine. As a reliable and highly repeatable verification method, the lead break test can not only effectively evaluate the coupling state of the acoustic emission detection front sensor and the test piece, but also verify the precision and accuracy of the acoustic emission positioning method, so the lead break test has important significance for the development of acoustic emission technology. However, in the actual lead break test, due to the large characteristic impedance between air and the test plate, the stress wave generated by the lead break will be reflected when propagating to the edge of the plate, so that the signal data collected by the acoustic emission sensor contains strong reflected signals, and the acoustic emission wave is prone to waveform transformation in multiple reflections, which eventually leads to serious interference in the collection of the wave source signal, greatly increasing the difficulty of acoustic emission signal processing and analysis.

[0003] In view of the influence of noise signals, the current methods mostly adopt signal processing methods such as empirical mode decomposition and Hilbert-Huang transformation to reduce noise of acoustic emission signals. Empirical mode decomposition defines the time delay between adjacent peak points of the original signal sequence as the time scale, decomposes the signal sequence into a series of intrinsic mode functions (IMF) of different scales, so that each IMF component signal is a stationary narrowband signal, thereby realizing signal noise reduction. Hilbert-Huang transformation is a time-frequency analysis method for processing nonlinear non-stationary signals, which can obtain time-frequency spectrum representation of the signal through empirical mode decomposition and instantaneous frequency solving.

[0004] The current signal processing methods are mostly suitable for reducing noise signals in the acquired signals, but for strong interference signals such as reflected signals caused by boundary reflection, the commonly used signal processing methods are difficult to calculate the key features of weak signals, and cannot effectively exclude the influence of noise on the target signal. SUMMARY

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application introduces the acoustic black hole theory into the design of the acoustic emission lead break test plate, and one purpose of the present application is to propose a reflected wave weakening test plate based on acoustic black hole effect, which can weaken the reflected wave at the edge of the test plate, and is safe and reliable to use, occupies small space and has simple structure.

[0006] The reflection wave weakening test board based on acoustic black hole effect according to the embodiment of the present application comprises:

[0007] A test board body;

[0008] A spiral acoustic black hole arranged at the edge of the test board body for weakening the reflection signal of the boundary.

[0009] The reflection wave weakening test board based on acoustic black hole effect according to the embodiment of the present application can effectively weaken the reflection signal of the test board boundary, because the spiral acoustic black hole is arranged at the edge of the test board body and the energy convergence effect of the spiral acoustic black hole can effectively reduce the reflection of acoustic emission wave, thereby facilitating the acoustic emission experimental data collection and analysis. Since the spiral acoustic black hole is in spiral curl shape, the end of the minimum thickness of the spiral acoustic black hole is not exposed, thereby ensuring the safety of the use of the reflection wave weakening test board based on acoustic black hole effect, and the occupied space is small. In summary, the reflection wave weakening test board based on acoustic black hole effect according to the embodiment of the present application can weaken the reflection wave of the test board edge, and is safe and reliable to use, small in occupied space, and simple in structure.

[0010] In some embodiments, the spiral acoustic black hole comprises a spiral curled wedge-shaped plate having opposite connecting end and end, the thickness of the wedge-shaped plate gradually decreases from the connecting end to the end, and the connecting end is connected with the edge of the test board body.

[0011] In some embodiments, when the wedge-shaped plate is in an unfolded state, one side of the wedge-shaped plate is a plane and the other side is a slope.

[0012] In some embodiments, the spiral acoustic black hole further comprises a flat plate with uniform thickness, one end of the flat plate is connected with the edge of the test board, the other end of the flat plate is connected with the connecting end of the wedge-shaped plate in end-to-end alignment, and the flat plate and the wedge-shaped plate are integrally formed.

[0013] In some embodiments, the thickness of the wedge-shaped plate gradually decreases from the connecting end to the end in the form of power index.

[0014] In some embodiments, the thickness of the wedge-shaped plate is:

[0015] d(x) = εx m +d0,(0≤x≤l)

[0016] wherein d(x) is the thickness of the wedge-shaped plate, d0 is the minimum thickness of the wedge-shaped plate, ε is a constant, m is a power index, and l is the length of the wedge-shaped plate between the connecting end and the end.

[0017] In some embodiments, the power index is: m≥2; the constant is:

[0018] In some embodiments, the wedge-shaped plate is curled according to an Archimedes spiral curve.

[0019] In some embodiments, the spiral curling of the wedge-shaped plate satisfies:

[0020]

[0021] Wherein a is the polar radius when θ=0°, b is the Archimedes spiral coefficient, and θ is the polar angle.

[0022] Additional aspects and advantages of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:

[0024] Figure 1 is a perspective view of a reflection wave weakening test plate based on acoustic black hole effect according to an embodiment of the present application;

[0025] Figure 2 is a perspective view of a spiral acoustic black hole in Figure 1 ;

[0026] Figure 3 is a perspective view of a spiral acoustic black hole in Figure 2 ;

[0027] Figure 4 is a perspective view of a spiral acoustic black hole in Figure 3 ;

[0028] Figure 5 is a perspective view of a spiral acoustic black hole in Figure 2 ;

[0029] Figure 6 is a simulation comparison experimental result diagram of a reflection wave weakening test plate based on acoustic black hole effect and a common test plate according to an embodiment of the present application.

[0030] LIST OF REFERENCE NUMERALS:

[0031] Reflection wave weakening test plate based on acoustic black hole effect 1000; test plate body 1; spiral acoustic black hole 2; wedge-shaped plate 201; connecting end 2011; end 2012; flat plate 202. DETAILED DESCRIPTION

[0032] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein the same or similar components or components having the same or similar functions are denoted by the same or similar reference numerals throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are only used to explain the present application and cannot be understood as a limitation of the present application.

[0033] The embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein the same or similar components or components having the same or similar functions are denoted by the same or similar reference numerals throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are only used to explain the present application and cannot be understood as a limitation of the present application. Figures 1 to 6 The acoustic black hole effect-based reflected wave weakening test plate 1000 of the embodiments of the present application is described below.

[0034] As shown in Figure 1 and Figure 2 The acoustic black hole effect-based reflected wave weakening test plate 1000 of the embodiments of the present application includes a test plate body 1 and a spiral acoustic black hole 2, the spiral acoustic black hole 2 is arranged at the edge of the test plate body 1, and is used to weaken the reflected signal of the test plate boundary.

[0035] The acoustic black hole effect-based reflected wave weakening test plate 1000 of the embodiments of the present application, since the edge of the test plate body 1 is provided with the spiral acoustic black hole 2, the energy convergence effect of the spiral acoustic black hole 2 can effectively reduce the reflection of acoustic emission waves, so that the reflected signal of the test plate boundary can be effectively weakened, thereby facilitating the acoustic emission experimental data collection and analysis. Since the spiral acoustic black hole 2 is in spiral curl shape, the minimum thickness end 2012 of the spiral acoustic black hole 2 is not exposed, which ensures the safety of the use of the acoustic black hole effect-based reflected wave weakening test plate 1000 of the present application, and also reduces the occupied space. In summary, the acoustic black hole effect-based reflected wave weakening test plate 1000 of the embodiments of the present application can weaken the reflected wave of the test plate edge, and is safe and reliable to use, small in occupied space, and simple in structure.

[0036] In some embodiments, as shown in Figure 2 The spiral acoustic black hole 2 includes a spiral curled wedge-shaped plate 201, the wedge-shaped plate 201 has opposite connecting ends 2011 and ends 2012, the thickness of the wedge-shaped plate 201 gradually decreases from the connecting end 2011 to the end 2012, and the connecting end 2011 is connected with the edge of the test plate body 1. Thus, the acoustic black hole effect-based reflected wave weakening test plate 1000 of this embodiment can effectively reduce the reflection of acoustic emission waves by using the energy convergence effect of the spiral acoustic black hole 2, effectively weaken the reflected signal of the test plate boundary, thereby facilitating the acoustic emission experimental data collection and analysis. At the same time, since the spiral acoustic black hole 2 is in spiral curl shape, the acoustic black hole effect-based reflected wave weakening test plate 1000 of this embodiment is safe and reliable to use, small in occupied space, and simple in structure.

[0037] In some embodiments, as shown in Figure 3 When the wedge-shaped plate 201 is in the unfolded state, one side of the wedge-shaped plate 201 is a flat surface and the other side is a slope. Thus, the wedge-shaped plate 201 can effectively reduce the reflection of sound emission waves by using the energy convergence effect, while the structure is simple and easy to process.

[0038] In some embodiments, as shown in Figures 1 to 3 The spiral acoustic black hole 2 further comprises a flat plate 202 with uniform thickness, one end of the flat plate 202 is connected to the edge of the test plate, and the other end of the flat plate 202 is connected to the end opposite to the connecting end 2011 of the wedge-shaped plate 201, and the flat plate 202 and the wedge-shaped plate 201 are integrally formed. By providing the flat plate 202, the wedge-shaped plate 201 is connected to the test plate body 1.

[0039] It should be noted that the spiral acoustic black hole 2 can be an independent processed piece connected to the test plate body 1, or an integral piece integrally processed with the test plate body 1.

[0040] In some embodiments, the thickness of the wedge-shaped plate 201 gradually decreases from the connecting end 2011 to the end 2012 in the form of a power index. Thus, the wedge-shaped plate 201 can effectively reduce the reflection of sound emission waves by using the energy convergence effect, while the structure is simple.

[0041] In some embodiments, as shown in Figure 3 and Figure 4 The thickness of the wedge-shaped plate 201 is:

[0042] d(x)=εx m +d0,(0≤x≤l)

[0043] wherein d(x) is the thickness of the wedge-shaped plate 201, d0 is the minimum thickness of the wedge-shaped plate 201, ε is a constant, m is a power index, and l is the length of the wedge-shaped plate 201 between the connecting end 2011 and the end 2012. Thus, the wedge-shaped plate 201 can effectively reduce the reflection of sound emission waves by using the energy convergence effect, while the structure is simple.

[0044] In some embodiments, the power index is: m≥2; and the constant is: Thus, the wedge-shaped plate 201 can effectively reduce the reflection of sound emission waves by using the energy convergence effect.

[0045] In some embodiments, as shown in Figure 5 The wedge-shaped plate 201 is curled according to an Archimedes spiral curve. Thus, the wedge-shaped plate 201 can effectively reduce the reflection of sound emission waves by using the energy convergence effect, while the structure is simple, occupies small space, and is safe and reliable.

[0046] In some embodiments, as shown in Figure 5As shown in the figure, the spiral curl of the wedge-shaped plate 201 satisfies:

[0047]

[0048] Wherein, a is the polar radius when θ = 0°, b is the Archimedes spiral line coefficient, and θ is the polar angle. Thus, the wedge-shaped plate 201 can effectively reduce the reflection of the acoustic emission wave by using the energy convergence effect, and has simple structure, small space occupation, and is safe and reliable.

[0049] In order to investigate the reflection wave weakening test plate 1000 based on the acoustic black hole effect of the embodiment of the present application, the weakening effect of the spiral acoustic black hole 2 on the reflection wave, the following gives a simulation comparison test with the ordinary test plate.

[0050] In the simulation comparison test, the specific size of the reflection wave weakening test plate 1000 based on the acoustic black hole effect of the embodiment of the present application can be as follows: as shown in the figure, Figures 1 to 3 The test plate body 1 is square, the thickness h of the test plate body 1 and the flat plate 202 of the acoustic black hole is 5mm, and the side length D is 400mm; the thickness d0 of the end 2012 of the spiral acoustic black hole 2 is 0.5mm, the length l of the spiral acoustic black hole 2 when unfolded is 100mm, and the power index m is 2.2.

[0051] Under the same working conditions, the finite element simulation software is used to give the same five-wave peak sinusoidal signal excitation to the reflection wave weakening test plate 1000 based on the acoustic black hole effect of the embodiment of the present application and the ordinary test plate, and output the signal at the same position.

[0052] As shown in the figure, Figure 6 By comparing the acoustic emission signals received by the sensors of the reflection wave weakening test plate 1000 based on the acoustic black hole effect of the embodiment of the present application and the ordinary test plate, it can be seen that the reflection wave signal amplitude received by the acoustic emission sensor corresponding to the reflection wave weakening test plate 1000 based on the acoustic black hole effect of the embodiment of the present application is significantly reduced, which shows that the reflection wave weakening test plate 1000 based on the acoustic black hole effect of the embodiment of the present application can significantly reduce the amplitude of the reflection wave, thereby being beneficial to the acoustic emission experimental data acquisition and analysis.

[0053] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0054] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and application of the present application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present application, which is defined by the following claims and their equivalents.

Claims

1. A test plate for attenuating reflected waves based on the acoustic black hole effect, characterized in that, include: Test plate body; A spiral acoustic black hole is disposed at the edge of the test plate body to attenuate the reflected signal at the boundary; The spiral acoustic black hole includes a spirally curled wedge plate, the wedge plate having opposing connecting ends and ends, the thickness of the wedge plate gradually decreasing from the connecting end to the end, and the connecting end being connected to the edge of the test plate body; The spiral acoustic black hole also includes a plate of uniform thickness. One end of the plate is connected to the edge of the test plate body, and the other end of the plate is aligned and connected to the connecting end of the wedge plate. The plate and the wedge plate are integrally formed. One end of the plate is aligned and connected to the edge of the test plate body end to end. The spiral acoustic black hole and the test plate body are integrally formed. The thickness of the wedge plate from the connecting end to the end gradually decreases in a power-law manner. The wedge-shaped plate is formed by rolling up an Archimedean spiral curve; The spiral curl of the wedge-shaped plate satisfies: ， in, a When θ Polar radius at 0° b It is the Archimedean spiral coefficient. θ It is the polar angle.

2. The acoustic black hole effect-based reflected wave attenuation test plate according to claim 1, characterized in that, When the wedge plate is in the unfolded state, one side of the wedge plate is a flat surface and the other side is a slope.

3. The acoustic black hole effect-based reflected wave attenuation test plate according to claim 1, characterized in that, The thickness of the wedge plate is: in, d ( x ) is the thickness of the wedge plate. d 0 represents the minimum thickness of the wedge plate. ε It is a constant. m The power exponent. l The length of the wedge plate between the connecting end and the end point.

4. The acoustic black hole effect-based reflected wave attenuation test plate according to claim 3, characterized in that, The power exponent is: m ≥2; the constant is: .

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