A method and system for non-contact measurement of longitudinal wave velocity of solid materials

Abstract

The present invention provides a method and system for non-contact measurement of the longitudinal wave velocity of solid materials, comprising: an ultrasonic transmitting probe; an ultrasonic receiving probe; a guide rail with a scale, the ultrasonic transmitting probe being fixed on the guide rail, and the ultrasonic receiving probe being able to slide on the guide rail; a clamp disposed on the guide rail for fixing the solid material to be measured; and a signal acquisition and processing unit, the signal acquisition and processing unit being connected to the ultrasonic transmitting probe and the ultrasonic receiving probe, for receiving probe signals and determining the longitudinal wave velocity of the solid material based on the relative position between the ultrasonic transmitting probe and the ultrasonic receiving probe and the phase relationship of the received signals. The present invention realizes a non-contact measurement device and method for the longitudinal wave velocity of solids, capable of measuring the longitudinal wave velocity of materials that are not suitable for contact, and has great advantages over traditional contact-based solid velocity measurement methods.

Description

Technical Field

[0001] The present invention relates to the technical field of solid material longitudinal wave sound velocity measurement, and in particular to a method and system for non-contact measurement of solid material longitudinal wave sound velocity. Background Art

[0002] The transit time method is currently widely used in practical engineering to measure the velocity of sound in solids. Its basic principle is that velocity = distance / time. The velocity of sound in solid materials is determined by knowing the material thickness and the propagation time of the ultrasonic wave. This method requires close contact between the ultrasonic probe and the material surface. A coupling agent is typically required between the ultrasonic probe and the material being measured. This often creates a mess in the lab environment and requires prompt cleaning after the measurement. This makes automated solid velocity measurement difficult and results in low measurement efficiency. Furthermore, in actual measurements, many materials are not suitable for contact with ultrasonic probes. For example, materials at high temperatures cannot come into contact with the probe; highly corrosive materials can easily damage the probe when in contact; and deformable materials can be compressed by the probe, resulting in reduced measurement accuracy. Furthermore, the contact method for measuring longitudinal wave velocity is particularly difficult when the material is very thin, making accurate measurement of the velocity of sound in thin films very challenging.

[0003] Therefore, it is necessary to develop a method and system for non-contact measurement of longitudinal wave velocity of solid materials to address the shortcomings of the existing technology and to solve or alleviate one or more of the above problems. Summary of the Invention

[0004] In view of this, the present invention provides a method and system for non-contact measurement of longitudinal wave sound velocity in solid materials, realizing a non-contact measurement device and method for longitudinal wave sound velocity in solids, capable of measuring longitudinal wave sound velocity in materials that are not suitable for contact, and at the same time, can measure longitudinal wave sound velocity in solids without contact and without using coupling agent, making it easy to automate longitudinal wave sound velocity measurement and improving measurement efficiency; compared with traditional contact solid sound velocity measurement methods, it has great advantages.

[0005] In one aspect, the present invention provides a system for non-contact measurement of longitudinal wave velocity of solid materials, the system comprising:

[0006] Ultrasonic transmitting probe;

[0007] Ultrasonic receiving probe;

[0008] A guide rail with a scale, the ultrasonic transmitting probe is fixed on the guide rail, and the ultrasonic receiving probe can slide on the guide rail;

[0009] A fixture, disposed on the guide rail and used for fixing the solid material to be tested;

[0010] and a signal acquisition and processing unit, wherein the signal acquisition and processing unit is connected to the ultrasonic transmitting probe and the ultrasonic receiving probe, and is used to receive probe signals and determine the longitudinal wave speed of the solid material according to the relative position between the ultrasonic transmitting probe and the ultrasonic receiving probe and the phase relationship of the received signals.

[0011] According to the aspects and any possible implementation described above, an implementation is further provided, wherein the system for non-contact measurement of longitudinal wave velocity of solid materials also includes a low-frequency signal generator, which is configured to output a low-frequency signal of a known frequency, and the low-frequency signal is used to drive the ultrasonic transmitting probe, and the ultrasonic transmitting probe is configured to transmit ultrasonic waves according to the low-frequency signal.

[0012] According to the aspects described above and any possible implementation method, an implementation method is further provided, wherein the signal acquisition and processing unit is configured to amplify the signal received by the ultrasonic receiving probe, and process the signal of the sound wave emitted by the ultrasonic transmitting probe and the signal of the sound wave received by the ultrasonic receiving probe, and the signal acquisition and processing unit is configured to display a Lissajous figure synthesized by the signal at the ultrasonic transmitting probe and the signal at the ultrasonic receiving probe, wherein the horizontal and vertical coordinates in the Lissajous figure respectively represent the instantaneous displacement values of two mutually perpendicular simple harmonic oscillation signals.

[0013] According to the aspects described above and any possible implementation method, an implementation method is further provided, in which the signal acquisition and processing unit is configured to, without installing solid material on the fixture, change the position of the ultrasonic receiving probe on the guide rail, observe the Lissajous figure shape displayed by the signal acquisition and processing unit, record multiple positions of the ultrasonic receiving probe on the guide rail when the Lissajous figure shape presents a specific phase relationship, and determine the speed of sound propagation in the air based on the multiple positions and the frequency output by the low-frequency signal generator.

[0014] According to the aspects and any possible implementation methods described above, an implementation method is further provided, wherein the fixture is configured to fix the solid material to be measured between the ultrasonic transmitting probe and the ultrasonic receiving probe, the solid material to be measured has a thickness, and the system for non-contact measurement of the longitudinal wave velocity of the solid material is configured to obtain the thickness of the solid material. After the solid material is fixed by the fixture, the ultrasonic wave emitted by the ultrasonic transmitting probe penetrates the solid material and reaches the ultrasonic receiving probe. At this time, the Lissajous figure displayed by the signal acquisition and processing unit is no longer a straight line.

[0015] According to the aspects described above and any possible implementation method, an implementation method is further provided, wherein the signal acquisition and processing unit is configured to adjust the position of the ultrasonic receiving probe on the guide rail when the solid material is fixed by the clamp so that the Lissajous figure displayed by the signal acquisition and processing unit presents the same specific phase relationship as when the solid material is not installed, and record the multiple positions of the ultrasonic receiving probe on the guide rail at this time.

[0016] According to the aspects described above and any possible implementation method, an implementation method is further provided, wherein the signal acquisition and processing unit is configured to calculate the longitudinal wave sound velocity in the solid material based on the sound propagation speed in the air determined when no solid material is installed on the fixture, the thickness of the solid material, and the multiple positions of the ultrasonic receiving probe on the guide rail recorded when the fixture fixes the solid material.

[0017] According to the aspects described above and any possible implementation methods, an implementation method is further provided, wherein the specific phase relationship includes: the phase difference between the signal at the ultrasonic transmitting probe and the signal at the ultrasonic receiving probe is zero or an integer multiple of π, and when the phase difference is zero or an integer multiple of π, the Lissajous figure displayed by the signal acquisition and processing unit appears as a straight line, and the recording of multiple positions of the ultrasonic receiving probe on the guide rail at this time includes recording the position of the ultrasonic receiving probe when the Lissajous figure changes from an ellipse to a straight line, and the position of the ultrasonic receiving probe when the Lissajous figure changes to a straight line again.

[0018] According to the above aspects and any possible implementation, a method for non-contact measurement of the longitudinal wave velocity of a solid material is further provided, wherein the measurement is performed by the system described above, and the method specifically comprises the following steps:

[0019] Step S1, obtaining a low-frequency sine and cosine signal of known frequency output by the low-frequency signal generator, wherein the low-frequency signal is used to drive the ultrasonic transmitting probe to transmit ultrasonic waves;

[0020] Step S2, using the ultrasonic transmitting probe to convert the low-frequency signal into ultrasonic waves and transmit the ultrasonic waves, wherein the ultrasonic waves propagate through the air or the solid material;

[0021] Step S3, when the fixture is not equipped with the solid material, the ultrasonic wave is transmitted through the air to the ultrasonic receiving probe, and the receiving probe receives the ultrasonic wave and outputs a receiving signal;

[0022] Step S4, using the signal acquisition and processing unit to acquire the transmitting probe signal and the receiving probe signal, and displaying a Lissajous figure of the initial position x0 based on the transmitting probe signal and the receiving probe signal;

[0023] Step S5, moving the ultrasonic receiving probe to a position x on the guide rail with scale k By observing the shape of the Lissajous figure displayed on the signal acquisition and processing unit, the position x of the receiving probe when the Lissajous figure is a specific shape is determined and recorded. k A collection of

[0024] Step S6, obtaining the thickness of the solid material, and mounting the solid material on the fixture, wherein the ultrasonic wave emitted by the ultrasonic transmitting probe penetrates the solid material and propagates to the ultrasonic receiving probe;

[0025] Step S7, using the signal acquisition processing unit to acquire the transmitting probe signal and the receiving probe signal, and displaying a Lissajous figure of the initial position y0 based on the transmitting probe signal and the receiving probe signal;

[0026] Step S8, moving the ultrasonic receiving probe to a position y on the guide rail with scale k By observing the shape of the Lissajous figure displayed on the signal acquisition and processing unit, the new position y of the receiving probe when the Lissajous figure reproduces the specific shape is determined and recorded. k A collection of

[0027] Step S9, using the signal acquisition processing unit, according to the low-frequency signal frequency, the initial position x0, the position x0 of the receiving probe k The set of initial position y0, the new position y of the receiving probe k and the thickness of the solid material, calculating the longitudinal wave sound velocity in the solid material;

[0028] Step S10: outputting the calculated longitudinal wave sound velocity value in the solid material.

[0029] According to the above aspects and any possible implementation manner, an implementation manner is further provided, wherein the method is used to measure high-temperature, highly corrosive and / or thin film materials.

[0030] Compared with the prior art, the present invention can achieve the following technical effects:

[0031] 1) The present invention uses Lissajous figures to measure the longitudinal wave velocity of solid materials. The ultrasonic transmitting probe is driven by a low-frequency signal, and ultrasonic waves are received in the air and solid materials respectively, and the Lissajous figures are displayed. The position of the receiving probe is moved, and the position set where a specific Lissajous figure appears is recorded. The longitudinal wave velocity in the solid material is calculated based on the difference in the receiving probe position in the two media, the signal frequency, and the material thickness.

[0032] 2) The present invention cleverly utilizes the changing characteristics of Lissajous figures to accurately obtain sound velocity data through simple position measurement, avoiding complex time measurement and improving measurement accuracy and efficiency. The method is simple to operate and is suitable for measuring the acoustic properties of various solid materials. It has important application value in fields such as material testing and acoustic research.

[0033] Of course, any product implementing the present invention does not necessarily need to achieve all of the above-mentioned technical effects at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 1 is a schematic diagram of a non-contact solid material longitudinal wave velocity measurement system provided by one embodiment of the present invention;

[0036] Figure 2 Schematic diagram of the changes in the Lissajous figure when the receiving probe position is moved according to an embodiment of the present invention;

[0037] Figure 3 is a schematic diagram of a Lissajous figure after insertion of a test material provided by one embodiment of the present invention;

[0038] Among them, in the figure: 1-guide rail with scale, 2-signal acquisition and processing unit, 3-low-frequency signal generator, 4-ultrasonic receiving probe, 5-ultrasonic transmitting probe, 6-clamp. DETAILED DESCRIPTION

[0039] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0040] It should be understood that the embodiments described are only a portion of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0041] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The singular forms "a", "an", "the" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0042] The present invention provides a system for non-contact measurement of the longitudinal wave velocity of solid materials, the system comprising:

[0043] Ultrasonic transmitting probe;

[0044] Ultrasonic receiving probe;

[0045] A guide rail with a scale, the ultrasonic transmitting probe is fixed on the guide rail, and the ultrasonic receiving probe can slide on the guide rail;

[0046] A fixture, disposed on the guide rail and used for fixing the solid material to be tested;

[0047] and a signal acquisition and processing unit, wherein the signal acquisition and processing unit is connected to the ultrasonic transmitting probe and the ultrasonic receiving probe, and is used to receive probe signals and determine the longitudinal wave speed of the solid material according to the relative position between the ultrasonic transmitting probe and the ultrasonic receiving probe and the phase relationship of the received signals.

[0048] The system for non-contact measurement of longitudinal wave velocity of solid materials also includes a low-frequency signal generator, which is configured to output a low-frequency signal of a known frequency. The low-frequency signal is used to drive the ultrasonic transmitting probe, and the ultrasonic transmitting probe is configured to transmit ultrasonic waves according to the low-frequency signal.

[0049] The signal acquisition and processing unit is configured to amplify the signal received by the ultrasonic receiving probe and process the signal of the sound wave emitted by the ultrasonic transmitting probe and the signal of the sound wave received by the ultrasonic receiving probe. The signal acquisition and processing unit is configured to display a Lissajous figure, which is a composite of the signal at the ultrasonic transmitting probe and the signal at the ultrasonic receiving probe. The Lissajous figure can measure the frequency ratio and phase difference between two signals. Therefore, an oscilloscope is used to observe the Lissajous figure and measure the frequency or phase difference. The measured sinusoidal signal and a standard signal of known frequency are respectively applied to the Y-axis input and X-axis input of the oscilloscope. The Lissajous figure displayed on the oscilloscope display can obtain frequency and phase information related to the measured sinusoidal signal. In the Lissajous figure described in the present invention, the horizontal and vertical coordinates respectively represent the instantaneous displacement values of two mutually perpendicular simple harmonic vibration signals. This is equivalent to a resonator performing simple harmonic vibration in the vertical direction (Y signal) and a resonator performing simple harmonic vibration in the horizontal direction (X signal). The composite of the two vibrations forms the Lissajous figure. The different frequencies and phases of the two oscillators result in different motion trajectories, and this combined motion trajectory forms the Lissajous figure.

[0050] The signal acquisition and processing unit is configured to, without installing any solid material on the fixture, change the position of the ultrasonic receiving probe on the guide rail and observe the Lissajous figure shape displayed by the signal acquisition and processing unit, record multiple positions of the ultrasonic receiving probe on the guide rail when the Lissajous figure shape presents a specific phase relationship, and determine the speed of sound propagation in the air based on the multiple positions and the frequency output by the low-frequency signal generator.

[0051] The fixture is configured to fix the solid material to be measured between the ultrasonic transmitting probe and the ultrasonic receiving probe. The solid material to be measured has a thickness. The system for non-contact measurement of the longitudinal wave velocity of solid materials is configured to obtain the thickness of the solid material. After the solid material is fixed by the fixture, the ultrasonic wave emitted by the ultrasonic transmitting probe penetrates the solid material and reaches the ultrasonic receiving probe. At this time, the Lissajous figure displayed by the signal acquisition and processing unit is no longer a straight line.

[0052] The signal acquisition and processing unit is configured to adjust the position of the ultrasonic receiving probe on the guide rail when the solid material is fixed by the clamp so that the Lissajous figure displayed by the signal acquisition and processing unit presents the same specific phase relationship as when the solid material is not installed, and record multiple positions of the ultrasonic receiving probe on the guide rail at this time.

[0053] The signal acquisition and processing unit is configured to calculate the longitudinal wave sound velocity in the solid material based on the sound propagation speed in the air determined when no solid material is installed on the fixture, the thickness of the solid material, and the multiple positions of the ultrasonic receiving probe on the guide rail recorded when the fixture fixes the solid material.

[0054] The specific phase relationship includes: the phase difference between the signal at the ultrasonic transmitting probe and the signal at the ultrasonic receiving probe is zero or an integer multiple of π; when the phase difference is zero or an integer multiple of π, the Lissajous figure displayed by the signal acquisition and processing unit appears as a straight line; and the recording of multiple positions of the ultrasonic receiving probe on the guide rail at this time includes recording the position of the ultrasonic receiving probe when the Lissajous figure changes from an ellipse to a straight line, and the position of the ultrasonic receiving probe when the Lissajous figure changes to a straight line again.

[0055] The present invention also provides a method for non-contact measurement of the longitudinal wave velocity of solid materials, which is performed by the system. The method specifically comprises the following steps:

[0056] Step S1, obtaining a low-frequency sine and cosine signal of known frequency output by the low-frequency signal generator, wherein the low-frequency signal is used to drive the ultrasonic transmitting probe to transmit ultrasonic waves;

[0057] Step S2, using the ultrasonic transmitting probe to convert the low-frequency signal into ultrasonic waves and transmit the ultrasonic waves, wherein the ultrasonic waves propagate through the air or the solid material;

[0058] Step S3, when the fixture is not equipped with the solid material, the ultrasonic wave is transmitted through the air to the ultrasonic receiving probe, and the receiving probe receives the ultrasonic wave and outputs a receiving signal;

[0059] Step S4, using the signal acquisition and processing unit to acquire the transmitting probe signal and the receiving probe signal, and displaying a Lissajous figure of the initial position x0 based on the transmitting probe signal and the receiving probe signal;

[0060] Step S5, moving the ultrasonic receiving probe to a position x on the guide rail with scale k By observing the shape of the Lissajous figure displayed on the signal acquisition and processing unit, the position x of the receiving probe when the Lissajous figure is a specific shape is determined and recorded. k A collection of

[0061] Step S6, obtaining the thickness of the solid material, and mounting the solid material on the fixture, wherein the ultrasonic wave emitted by the ultrasonic transmitting probe penetrates the solid material and propagates to the ultrasonic receiving probe;

[0062] Step S7, using the signal acquisition processing unit to acquire the transmitting probe signal and the receiving probe signal, and displaying a Lissajous figure of the initial position y0 based on the transmitting probe signal and the receiving probe signal;

[0063] Step S8, moving the ultrasonic receiving probe to a position y on the guide rail with scale k By observing the shape of the Lissajous figure displayed on the signal acquisition and processing unit, the new position y of the receiving probe when the Lissajous figure reproduces the specific shape is determined and recorded. k A collection of

[0064] Step S9, using the signal acquisition processing unit, according to the low-frequency signal frequency, the initial position x0, the position x0 of the receiving probe k The set of initial position y0, the new position y of the receiving probe k and the thickness of the solid material, calculating the longitudinal wave sound velocity in the solid material;

[0065] Step S10: outputting the calculated longitudinal wave sound velocity value in the solid material.

[0066] The method is useful for measuring high temperature, highly corrosive and / or thin film materials.

[0067] Example 1:

[0068] The present invention provides a non-contact device for measuring the longitudinal wave velocity of a material, the structure and connection of which are as follows: Figure 1 Shown: including,

[0069] Low-frequency signal generator: can output low-frequency sine and cosine signals of known frequency.

[0070] Ultrasonic transmitting probe: In order to improve the ability to penetrate solid materials, the required probe must have sufficiently high power.

[0071] Ultrasonic receiving probe: It is configured on the side opposite to the transmitting probe and receives the sound waves that pass through the object being measured.

[0072] Guide rail with scale: The transmitting probe is fixed at the zero scale of the guide rail, and the receiving probe can slide on the guide rail. The position of the receiving probe can be read through the scale. A fixture for fixing the material to be tested is set on the guide rail between the two probes.

[0073] Signal acquisition and processing unit: amplifies the signal received by the receiving probe and processes the sound waves emitted by the transmitting probe and the sound waves received by the receiving probe, displays the Lissajous figure of the synthesis of the signal at the transmitting probe and the signal at the receiving probe, and can process the measurement data.

[0074] In the non-contact solid material longitudinal wave sound velocity measurement device of the present invention, the longitudinal wave sound velocity measurement method is implemented by the following technical solution:

[0075] Step 1: Without installing any solid material on the fixture, the ultrasonic wave generated by the transmitting probe is transmitted directly through the air to the receiving probe. The traveling wave method is first used to measure the current sound speed in the air. The specific operation is as follows:

[0076] Experimental setup such as Figure 1 As shown in the figure, in the experiment, the position of the receiving probe on the guide rail is changed, and the shape of the Lissajous figure on the signal acquisition processor is observed. When the Lissajous figure changes from an ellipse to a straight line, the position x1 of the probe is recorded. The receiving probe is continued to be moved, and the figure changes to an ellipse again, and then to a straight line again, as shown in the figure. Figure 2 As shown, record the probe position x2, continue to move the receiving probe until the graph becomes a straight line again, and record the probe position x at this time. 3， By analogy, N positions of the probe are measured in the same way. The difference between two adjacent readings should theoretically be half the wavelength. Then, the propagation speed of the ultrasonic wave in the air can be calculated by multiplying the wavelength by the output frequency of the low-frequency signal generator. .

[0077] Step 2: Adjust the position of the receiving probe so that the Lissajous figure displayed on the signal collector is a straight line. At this point, record the position of the receiving probe as y0. The phase difference between the sound source and the receiving probe is expressed as follows:

[0078]

[0079] Where f is the frequency of the ultrasonic wave, is the phase difference between the sound source and the receiving probe.

[0080] After measuring the thickness d of the material with a micrometer, fix the solid material to the fixture (the thickness of the material should be as small as possible to facilitate the ultrasonic wave to penetrate the material). The ultrasonic wave can penetrate the material to be measured and reach the receiving probe. At this time, you can see that the Lissajous figure is no longer a straight line (such as Figure 3 ), adjust the position of the receiving probe so that it moves away from the transmitting probe. When the Lissajous figure changes from an ellipse to a straight line in the same quadrant, record the position y1 of the receiving probe at this time. Continue to move the probe. When a straight line in the same quadrant appears again, record the position y2 of the receiving probe at this time. Similarly, record the position of the receiving probe. If y k is the position of the receiving probe when the straight line appears before the k-th reappearance of the Lissajous figure, then the phase difference between the sound source and the receiving probe satisfies the following relationship:

[0081] ;

[0082] but and The relationship is as follows:

[0083] ;

[0084] in, is the phase difference between the sound source and the receiving probe when the Lissajous figure reappears for the kth time.

[0085] Using the above formulas, the longitudinal wave speed in solid materials is It can be calculated using the following formula:

[0086] ;

[0087] The data recorded in the measurement is input into the signal acquisition and processing unit for processing and calculation, and the measured value of the longitudinal wave sound velocity is output.

[0088] The present invention provides a non-contact device and method for measuring the longitudinal wave velocity in solids. This device and method are capable of measuring the longitudinal wave velocity in materials that are not suitable for contact. This method, without the use of contact or coupling agents, facilitates automated measurement of the longitudinal wave velocity, improving measurement efficiency. Because the traditional contact-based transit time method is extremely difficult to obtain when the material being measured is too thin, the present invention is particularly suitable for measuring the longitudinal wave velocity in thin materials, offering significant advantages over traditional solid velocity measurement methods.

[0089] The above describes in detail a method and system for non-contact measurement of longitudinal wave velocity in solid materials, as provided in the embodiments of the present application. The description of the above embodiments is intended only to facilitate understanding of the method and core concept of the present application. Furthermore, those skilled in the art will appreciate that variations in the specific implementation and scope of application may occur based on the concepts of the present application. In summary, the contents of this specification should not be construed as limiting the present application.

[0090] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" and "comprising" mentioned throughout the specification and claims are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problems within a certain error range and basically achieve the technical effects. The subsequent description in the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be as defined in the attached claims.

[0091] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or system. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or system comprising the element.

[0092] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0093] The above description shows and describes several preferred embodiments of the present application. However, as previously mentioned, it should be understood that the present application is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present application can be used in various other combinations, modifications, and environments and can be modified within the scope of the application concept described herein through the above teachings or technology or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present application should be protected by the claims appended hereto.

Claims

1. A system for non-contact measurement of longitudinal wave velocity of solid materials, characterized in that: The non-contact system for measuring the longitudinal wave velocity of solid materials comprises: Ultrasonic transmitting probe; Ultrasonic receiving probe; A guide rail with a scale, the ultrasonic transmitting probe is fixed on the guide rail, and the ultrasonic receiving probe can slide on the guide rail; A fixture, disposed on the guide rail and used for fixing the solid material to be tested; and a signal acquisition and processing unit, wherein the signal acquisition and processing unit is connected to the ultrasonic transmitting probe and the ultrasonic receiving probe, and is used to receive probe signals and determine the longitudinal wave speed of the solid material according to the relative position between the ultrasonic transmitting probe and the ultrasonic receiving probe and the phase relationship of the received signals.

2. The system for non-contact measurement of longitudinal wave velocity of solid materials according to claim 1, characterized in that: The system for non-contact measurement of longitudinal wave velocity of solid materials also includes a low-frequency signal generator, which is configured to output a low-frequency signal of a known frequency. The low-frequency signal is used to drive the ultrasonic transmitting probe, and the ultrasonic transmitting probe is configured to transmit ultrasonic waves according to the low-frequency signal.

3. The system for non-contact measurement of longitudinal wave velocity of solid materials according to claim 1, characterized in that: The signal acquisition and processing unit is configured to amplify the signal received by the ultrasonic receiving probe, and process the signal of the sound wave emitted by the ultrasonic transmitting probe and the signal of the sound wave received by the ultrasonic receiving probe. The signal acquisition and processing unit is configured to display a Lissajous figure synthesized by the signal at the ultrasonic transmitting probe and the signal at the ultrasonic receiving probe, wherein the horizontal and vertical coordinates in the Lissajous figure respectively represent the instantaneous displacement values of two mutually perpendicular simple harmonic vibration signals.

4. The system for non-contact measurement of longitudinal wave velocity of solid materials according to claim 2, characterized in that: The signal acquisition and processing unit is configured to, without installing any solid material on the fixture, change the position of the ultrasonic receiving probe on the guide rail and observe the Lissajous figure shape displayed by the signal acquisition and processing unit, record multiple positions of the ultrasonic receiving probe on the guide rail when the Lissajous figure shape presents a specific phase relationship, and determine the speed of sound propagation in the air based on the multiple positions and the frequency output by the low-frequency signal generator.

5. The system for non-contact measurement of longitudinal wave velocity of solid materials according to claim 1, characterized in that: The fixture is configured to fix the solid material to be measured between the ultrasonic transmitting probe and the ultrasonic receiving probe. The solid material to be measured has a thickness. The system for non-contact measurement of the longitudinal wave velocity of solid materials is configured to obtain the thickness of the solid material. After the solid material is fixed by the fixture, the ultrasonic wave emitted by the ultrasonic transmitting probe penetrates the solid material and reaches the ultrasonic receiving probe. At this time, the Lissajous figure displayed by the signal acquisition and processing unit is no longer a straight line.

6. The system for non-contact measurement of longitudinal wave velocity of solid materials according to claim 5, characterized in that: The signal acquisition and processing unit is configured to adjust the position of the ultrasonic receiving probe on the guide rail when the solid material is fixed by the clamp so that the Lissajous figure displayed by the signal acquisition and processing unit presents the same specific phase relationship as when the solid material is not installed, and record multiple positions of the ultrasonic receiving probe on the guide rail at this time.

7. The system for non-contact measurement of longitudinal wave velocity of solid materials according to claim 6, characterized in that: The signal acquisition and processing unit is configured to calculate the longitudinal wave sound velocity in the solid material based on the sound propagation speed in the air determined when no solid material is installed on the fixture, the thickness of the solid material, and the multiple positions of the ultrasonic receiving probe on the guide rail recorded when the fixture fixes the solid material.

8. The system for non-contact measurement of longitudinal wave velocity of solid materials according to claim 6, characterized in that: The specific phase relationship includes: the phase difference between the signal at the ultrasonic transmitting probe and the signal at the ultrasonic receiving probe is zero or an integer multiple of π; when the phase difference is zero or an integer multiple of π, the Lissajous figure displayed by the signal acquisition and processing unit appears as a straight line; and the recording of multiple positions of the ultrasonic receiving probe on the guide rail at this time includes recording the position of the ultrasonic receiving probe when the Lissajous figure changes from an ellipse to a straight line, and the position of the ultrasonic receiving probe when the Lissajous figure changes to a straight line again.

9. A method for non-contact measurement of longitudinal wave velocity of solid materials, comprising: The method specifically comprises the following steps: Step S1, obtaining a low-frequency sine and cosine signal of known frequency output by a low-frequency signal generator, wherein the low-frequency sine and cosine signal is used to drive the ultrasonic transmitting probe to transmit ultrasonic waves; Step S2, using the ultrasonic transmitting probe to convert the low-frequency sine and cosine signals into ultrasonic waves and transmit the ultrasonic waves, wherein the ultrasonic waves propagate through the air or the solid material; Step S3, when the fixture is not equipped with the solid material, the ultrasonic wave is transmitted through the air to the ultrasonic receiving probe, and the receiving probe receives the ultrasonic wave and outputs a receiving signal; Step S4, using the signal acquisition and processing unit to acquire the signal of the ultrasonic transmitting probe and the signal of the ultrasonic receiving probe, and displaying a Lissajous figure of the initial position x0 based on the signal of the ultrasonic transmitting probe and the signal of the ultrasonic receiving probe; Step S5, moving the ultrasonic receiving probe to a position x on the guide rail with scale k By observing the shape of the Lissajous figure displayed on the signal acquisition and processing unit, the position x of the receiving probe when the Lissajous figure is a specific shape is determined and recorded. k A collection of Step S6, obtaining the thickness of the solid material, and mounting the solid material on the fixture, wherein the ultrasonic wave emitted by the ultrasonic transmitting probe penetrates the solid material and propagates to the ultrasonic receiving probe; Step S7, using the signal acquisition processing unit to acquire the transmitting probe signal and the receiving probe signal, and displaying a Lissajous figure of the initial position y0 based on the transmitting probe signal and the receiving probe signal; Step S8, moving the ultrasonic receiving probe to a position y on the guide rail with scale k By observing the shape of the Lissajous figure displayed on the signal acquisition and processing unit, the new position y of the receiving probe when the Lissajous figure reproduces the specific shape is determined and recorded. k A collection of Step S9, using the signal acquisition processing unit, according to the frequency of the low-frequency signal generator, the initial position x0, the position x0 of the receiving probe k The set of initial position y0, the new position y of the receiving probe k and the thickness of the solid material, calculating the longitudinal wave sound velocity in the solid material; Step S10: outputting the calculated longitudinal wave sound velocity value in the solid material.

10. The method for non-contact measurement of longitudinal wave velocity of solid material according to claim 9, characterized in that: The method is useful for measuring high temperature, highly corrosive and / or thin film materials.

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