A method and system for testing material shear wave sound velocity based on longitudinal wave straight probe

Abstract

The application relates to the technical field of nondestructive testing and ultrasonic measurement, and discloses a material transverse wave sound velocity testing method and system based on a longitudinal wave straight probe, which comprises the following steps: transmitting a longitudinal wave ultrasonic signal to a measured material by the longitudinal wave straight probe, receiving an ultrasonic echo signal and measuring the propagation time of each ultrasonic echo signal; based on a first bottom surface longitudinal wave echo, a second bottom surface longitudinal wave echo and the corresponding propagation time difference, the one-way longitudinal wave propagation time in the measured material is obtained by analysis; based on the first bottom surface longitudinal wave echo, the first bottom surface transverse wave echo and the corresponding propagation time difference, and combined with the one-way longitudinal wave propagation time in the measured material, the one-way transverse wave propagation time in the measured material is calculated; and according to the thickness of the measured material and the one-way transverse wave propagation time in the measured material, the transverse wave sound velocity of the measured material is calculated. The longitudinal wave multiple bottom surface reflection signal and the longitudinal wave transverse wave conversion signal are analyzed, so that the accurate measurement of the transverse wave sound velocity of the material is realized.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing and ultrasonic measurement technology, and more specifically, to a method and system for testing the transverse wave velocity of materials based on a longitudinal wave straight probe. Background Technology

[0002] Shear wave velocity is an important physical parameter characterizing the elastic properties, microstructure, and internal consistency of a material, and it has significant application value in ultrasonic testing, structural integrity assessment, and numerical simulation modeling.

[0003] In existing technologies, transverse wave velocity is usually obtained by direct measurement using a transverse wave probe. However, this method requires an additional transverse wave probe and has high requirements for probe installation angle, coupling state, and material surface conditions. The test stability and repeatability are poor, and it is not easy to implement in some structural or space-constrained scenarios.

[0004] Therefore, there is an urgent need for a detection method and system that can measure the shear wave velocity of materials based on a longitudinal wave straight probe without requiring a dedicated shear wave probe, so as to improve the applicability of the test and the reliability of the measurement. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the shortcomings of existing transverse wave sound velocity measurement technology, which relies on dedicated transverse wave probes and has insufficient test stability and applicability. This invention addresses the problems of traditional measurement methods relying on dedicated transverse wave probes, having strict requirements on probe installation angle and coupling conditions, being difficult to implement in special structures and space-constrained scenarios, and having poor test repeatability and stability. The invention proposes a material transverse wave sound velocity testing method and system based on a longitudinal wave straight probe.

[0006] To address the aforementioned technical problems, this invention proposes a method and system for testing transverse wave sound velocity in materials based on a longitudinal wave straight probe.

[0007] According to one aspect of the present invention, a method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe is provided, the method comprising the following steps: S1. Couple the longitudinal wave straight probe to the surface of the material being tested, emit longitudinal wave ultrasonic signals into the interior of the material being tested, receive ultrasonic echo signals, and measure the propagation time of each ultrasonic echo signal; the ultrasonic echo signals include a primary bottom longitudinal wave echo, a secondary bottom longitudinal wave echo, and a primary bottom transverse wave echo. S2. Based on the first bottom longitudinal wave echo, the second bottom longitudinal wave echo and their corresponding propagation time difference, the one-way longitudinal wave propagation time in the tested material is obtained analytically. S3. Based on the first bottom longitudinal wave echo, the first bottom transverse wave echo and their corresponding propagation time difference, and combined with the one-way longitudinal wave propagation time in the tested material, the one-way transverse wave propagation time in the tested material is calculated. S4. Calculate the transverse wave velocity of the material under test based on the thickness of the material and the one-way transverse wave propagation time within the material.

[0008] Further, S1 includes: S11. The longitudinal wave straight probe is vertically placed on the surface of the material to be tested, and longitudinal wave ultrasonic signals are emitted to the material to be tested through the coupling medium. S12. Receive the ultrasonic echo signal returned after reflection and mode conversion of the bottom surface inside the material being tested, and identify the first bottom longitudinal wave echo, the second bottom longitudinal wave echo and the first bottom transverse wave echo from the ultrasonic echo signal. S13. The propagation time of the first bottom longitudinal wave echo, the second bottom longitudinal wave echo, and the first bottom transverse wave echo were measured respectively.

[0009] Furthermore, the propagation time of the longitudinal wave echo on the bottom surface includes: the one-way propagation time of the longitudinal wave ultrasonic signal from the longitudinal wave probe to the upper surface of the material under test, the propagation time of the longitudinal wave ultrasonic signal traveling back and forth once along the thickness direction inside the material under test, and the one-way propagation time of the longitudinal wave ultrasonic signal returning from the upper surface of the material under test to the longitudinal wave probe.

[0010] Furthermore, the secondary bottom longitudinal wave echo propagation time includes: the one-way propagation time of the longitudinal wave ultrasonic signal from the longitudinal wave straight probe to the upper surface of the material under test, the propagation time of the longitudinal wave ultrasonic signal traveling back and forth twice along the thickness direction inside the material under test, and the one-way propagation time of the longitudinal wave ultrasonic signal returning from the upper surface of the material under test to the longitudinal wave straight probe.

[0011] Furthermore, the propagation path of the first bottom surface transverse wave echo is as follows: the longitudinal wave ultrasonic signal is emitted from the longitudinal wave straight probe, enters the interior of the material under test through the upper surface of the material under test, propagates along the thickness direction to the bottom surface of the material under test, and generates a transverse wave by mode conversion at the bottom surface of the material under test. The transverse wave returns to the upper surface of the material under test along the thickness direction of the material under test, forming a first bottom surface transverse wave echo, which is received by the longitudinal wave straight probe.

[0012] Furthermore, the propagation time of the bottom surface transverse wave echo includes: the round-trip propagation time of the longitudinal wave ultrasonic signal between the longitudinal wave straight probe and the upper surface of the material under test, the propagation time of the longitudinal wave ultrasonic signal propagating one way along the thickness direction inside the material under test to the bottom surface, and the propagation time of the transverse wave generated by the bottom surface mode conversion returning one way along the thickness direction inside the material under test to the upper surface.

[0013] Furthermore, the formula for calculating the one-way longitudinal wave propagation time within the tested material is as follows: TL2=(T2−T1) / 2; In the formula, T1 is the propagation time of the first longitudinal wave echo from the bottom surface; T2 is the propagation time of the second longitudinal wave echo from the bottom surface; and TL2 is the one-way longitudinal wave propagation time within the material being tested.

[0014] Furthermore, the formula for calculating the one-way transverse wave propagation time within the tested material is as follows: TS2=(T s −T1)+TL2; In the formula, T s T1 is the propagation time of a single bottom surface transverse wave echo; T2 is the propagation time of a single bottom surface longitudinal wave echo; TL2 is the one-way longitudinal wave propagation time within the tested material; TS2 is the one-way transverse wave propagation time within the tested material.

[0015] Furthermore, the formula for calculating the transverse wave velocity of the tested material is as follows: Cs=H / TS2; In the formula, H is the thickness of the material being tested; TS2 is the one-way transverse wave propagation time within the material being tested; and Cs is the transverse wave velocity of the material being tested.

[0016] According to another aspect of the present invention, a material transverse wave sound velocity testing system based on a longitudinal wave straight probe is provided, the system comprising: An ultrasonic transceiver timing module is used to couple a longitudinal wave straight probe to the surface of the material under test, transmit longitudinal wave ultrasonic signals into the interior of the material under test, receive ultrasonic echo signals, and measure the propagation time of each ultrasonic echo signal; the ultrasonic echo signals include a primary bottom longitudinal wave echo, a secondary bottom longitudinal wave echo, and a primary bottom transverse wave echo. The longitudinal wave time difference analysis module is used to analyze the one-way longitudinal wave propagation time in the tested material based on the primary bottom surface longitudinal wave echo, the secondary bottom surface longitudinal wave echo and their corresponding propagation time difference. The transverse wave time difference calculation module is used to calculate the one-way transverse wave propagation time in the tested material based on the first bottom surface longitudinal wave echo, the first bottom surface transverse wave echo and their corresponding propagation time difference, and combined with the one-way longitudinal wave propagation time in the tested material. The transverse wave velocity conversion module is used to calculate the transverse wave velocity of the tested material based on the thickness of the tested material and the one-way transverse wave propagation time within the tested material.

[0017] The beneficial effects of this invention are as follows: 1. This invention can achieve transverse wave sound velocity testing using only a longitudinal wave straight probe, significantly reducing hardware configuration complexity and testing costs. It eliminates the need for a dedicated transverse wave probe and its associated probe rotation device, avoiding the stringent requirements of transverse wave probes regarding installation angle and coupling state. Operation is simple and suitable for rapid on-site testing.

[0018] 2. This invention analyzes the propagation time of longitudinal waves by using the time difference between multiple bottom surface longitudinal wave echoes, effectively eliminating systematic errors such as coupling layer and probe delay, and improving measurement accuracy. The one-way propagation time of the longitudinal wave is calculated using the time difference between the first and second bottom surface longitudinal wave echoes, resulting in more accurate and reliable measurement results.

[0019] 3. This invention utilizes the mode conversion signal naturally generated by the longitudinal wave on the bottom surface of the material to estimate the propagation time of the transverse wave, resulting in high test stability and good repeatability. By performing differential calculations on the longitudinal and transverse wave components in the same echo sequence, the influence of coupling state fluctuations between the probe and the tested material is eliminated, avoiding measurement deviations introduced by changes in coupling conditions in traditional methods.

[0020] 4. This invention is applicable to a variety of materials and structural forms, and has a wide range of applications. It is particularly suitable for detection scenarios where traditional shear wave probes are difficult to implement or have poor signal quality, such as thin-walled structures, curved workpieces, space-constrained structures, and composite laminates, and has good engineering promotion value. Attached Figure Description

[0021] The invention will now be further described with reference to the accompanying drawings.

[0022] Figure 1 A flowchart illustrating a material transverse wave sound velocity testing method based on a longitudinal wave straight probe, as an example of the present invention; Figure 2 This is a schematic diagram of a material transverse wave sound velocity testing system based on a longitudinal wave straight probe, as an example of the present invention. Figure 3 This is a schematic diagram illustrating the installation relationship between the longitudinal wave straight probe and the material under test, as well as the ultrasonic propagation path, in an example of the present invention. Figure 4 This is a schematic diagram illustrating the time relationship between multiple bottom longitudinal wave echoes and echoes containing transverse wave components, as exemplified by this invention.

[0023] In the picture: 1. Ultrasonic transceiver timing module; 2. Longitudinal wave time difference analysis module; 3. Transverse wave time difference calculation module; 4. Transverse wave sound velocity conversion module. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings, which will make the technical approach and operation steps of the present invention clearer.

[0025] According to an embodiment of the present invention, a method and system for testing the transverse wave velocity of materials based on a longitudinal wave straight probe are provided.

[0026] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments, such as... Figure 1As shown, according to an embodiment of the present invention, a method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe is provided, the method comprising the following steps: S1. Couple the longitudinal wave straight probe to the surface of the material being tested, emit longitudinal wave ultrasonic signals into the interior of the material being tested, receive ultrasonic echo signals, and measure the propagation time of each ultrasonic echo signal; the ultrasonic echo signals include a primary bottom longitudinal wave echo, a secondary bottom longitudinal wave echo, and a primary bottom transverse wave echo. Specifically, S1 includes: S11. The longitudinal wave straight probe is vertically placed on the surface of the material to be tested, and longitudinal wave ultrasonic signals are emitted to the material to be tested through the coupling medium. S12. Receive the ultrasonic echo signal returned after reflection and mode conversion of the bottom surface inside the material being tested, and identify the first bottom longitudinal wave echo, the second bottom longitudinal wave echo and the first bottom transverse wave echo from the ultrasonic echo signal. S13. The propagation time of the first bottom longitudinal wave echo, the second bottom longitudinal wave echo, and the first bottom transverse wave echo were measured respectively.

[0027] Specifically, the propagation time of the longitudinal wave echo on the bottom surface includes: the one-way propagation time of the longitudinal wave ultrasonic signal from the longitudinal wave probe to the upper surface of the material under test, the propagation time of the longitudinal wave ultrasonic signal traveling back and forth once along the thickness direction inside the material under test, and the one-way propagation time of the longitudinal wave ultrasonic signal returning from the upper surface of the material under test to the longitudinal wave probe.

[0028] Specifically, the propagation path of a single bottom-surface longitudinal wave echo is as follows: the longitudinal wave ultrasonic signal exits from the longitudinal wave direct probe, enters the upper surface of the material under test, propagates along the thickness direction to the bottom surface of the material under test, is reflected at the bottom surface, returns along the thickness direction to the upper surface of the material under test, penetrates the upper surface, and is received by the longitudinal wave direct probe. The propagation time model of a single bottom-surface longitudinal wave echo is: T1 = TL1 + 2·TL2 + TL1; In the formula, T1 is the propagation time of the longitudinal wave echo on the bottom surface; TL1 is the one-way propagation time of the longitudinal wave between the longitudinal wave probe and the upper surface of the material under test; and TL2 is the one-way propagation time of the longitudinal wave inside the material under test.

[0029] Specifically, the secondary bottom longitudinal wave echo propagation time includes: the one-way propagation time of the longitudinal wave ultrasonic signal from the longitudinal wave straight probe to the upper surface of the material under test, the propagation time of the longitudinal wave ultrasonic signal traveling back and forth twice along the thickness direction inside the material under test, and the one-way propagation time of the longitudinal wave ultrasonic signal returning from the upper surface of the material under test to the longitudinal wave straight probe.

[0030] Specifically, the propagation path of the secondary bottom-surface longitudinal wave echo is as follows: the longitudinal wave ultrasonic signal exits from the longitudinal wave direct probe, enters the upper surface of the tested material, propagates along the thickness direction to the bottom surface of the tested material, undergoes a first reflection at the bottom surface, returns to the upper surface of the tested material, undergoes a second reflection at the upper surface, propagates downwards again to the bottom surface of the tested material, undergoes a third reflection at the bottom surface, returns along the thickness direction to the upper surface of the tested material, penetrates the upper surface, and is received by the longitudinal wave direct probe. The propagation time model of the secondary bottom-surface longitudinal wave echo is: T2 = TL1 + 4·TL2 + TL1; In the formula, T2 is the propagation time of the secondary bottom longitudinal wave echo; TL1 is the one-way propagation time of the longitudinal wave between the longitudinal wave probe and the upper surface of the material under test; and TL2 is the one-way propagation time of the longitudinal wave inside the material under test.

[0031] Specifically, the propagation path of the first bottom surface transverse wave echo is as follows: the longitudinal wave ultrasonic signal is emitted from the longitudinal wave straight probe, enters the interior of the material under test through the upper surface of the material under test, propagates along the thickness direction to the bottom surface of the material under test, and generates a transverse wave by mode conversion at the bottom surface of the material under test. The transverse wave returns to the upper surface of the material under test along the thickness direction of the material under test, forming a first bottom surface transverse wave echo, which is received by the longitudinal wave straight probe.

[0032] Specifically, the propagation time of the bottom surface transverse wave echo includes: the round-trip propagation time of the longitudinal wave ultrasonic signal between the longitudinal wave straight probe and the upper surface of the material under test, the propagation time of the longitudinal wave ultrasonic signal propagating one way along the thickness direction inside the material under test to the bottom surface, and the propagation time of the transverse wave generated by the bottom surface mode conversion returning one way along the thickness direction inside the material under test to the upper surface.

[0033] Specifically, the propagation path of a single bottom-surface shear wave echo is as follows: the longitudinal wave ultrasonic signal exits from the longitudinal wave direct probe, enters the upper surface of the tested material, and propagates one-way along the thickness direction in longitudinal mode to the bottom surface of the tested material. At the bottom surface, a mode conversion occurs, generating a shear wave. This shear wave returns one-way along the thickness direction in shear mode to the upper surface of the tested material, penetrates the upper surface, and is received by the longitudinal wave direct probe. The propagation time model of a single bottom-surface shear wave echo is: T s =TL1+TL2+TS2+TL1; In the formula, T s TL1 is the propagation time of a single bottom transverse wave echo; TL2 is the one-way propagation time of the longitudinal wave between the longitudinal wave probe and the upper surface of the material under test; TL3 is the one-way propagation time of the longitudinal wave inside the material under test; TS2 is the one-way propagation time of the transverse wave inside the material under test.

[0034] Specifically, such as Figure 3 The diagram shown illustrates the installation relationship between the longitudinal wave straight probe and the material being tested, as well as the ultrasonic propagation path. Figure 3In the diagram, red represents longitudinal waves and blue represents transverse waves. The longitudinal wave straight probe is positioned perpendicularly to the surface of the material being tested and emits longitudinal wave ultrasonic signals into the material through a coupling medium.

[0035] Longitudinal wave ultrasonic signals propagate along the thickness direction in the tested material and are reflected at the bottom surface to form bottom longitudinal wave echoes. Part of the longitudinal wave undergoes mode conversion at the bottom surface, forming transverse wave components that propagate along the material's interior. By collecting echo signals corresponding to different propagation paths, fundamental data is provided for analyzing the propagation time of longitudinal and transverse waves.

[0036] like Figure 4 The diagram shown illustrates the time relationship between multiple bottom surface longitudinal wave echoes and echoes containing transverse wave components. Figure 4 The horizontal axis represents time, and the vertical axis represents the amplitude of the echo signal. Figure 4 The diagram shows the distribution of echo signals along the time axis for different propagation paths.

[0037] The earlier arriving echo signal corresponds to the bottom longitudinal wave echo formed by the longitudinal wave propagating back and forth once or multiple times in the material under test; the later arriving echo signal appearing at a specific propagation distance is the echo signal containing the propagation path of the transverse wave formed after the longitudinal wave undergoes mode conversion on the bottom surface of the material. By analyzing the time relationship between the above echo signals, the longitudinal wave propagation time parameters and the transverse wave propagation time parameters are obtained, thereby realizing the measurement of the transverse wave velocity of the material under test.

[0038] S2. Based on the first bottom longitudinal wave echo, the second bottom longitudinal wave echo and their corresponding propagation time difference, the one-way longitudinal wave propagation time in the tested material is obtained analytically. Specifically, the formula for calculating the one-way longitudinal wave propagation time within the tested material is as follows: TL2=(T2−T1) / 2; In the formula, T1 is the propagation time of the first longitudinal wave echo from the bottom surface; T2 is the propagation time of the second longitudinal wave echo from the bottom surface; and TL2 is the one-way longitudinal wave propagation time within the material being tested.

[0039] Specifically, by subtracting the propagation time T1 of the first bottom longitudinal wave echo from the second bottom longitudinal wave echo from the third bottom wave echo, the common term TL1 can be eliminated, and the propagation time T2−T1 of the longitudinal wave along a path twice the thickness inside the material under test can be obtained. Taking half of this time, the one-way propagation time TL2=(T2−T1) / 2 of the longitudinal wave inside the material under test can be obtained.

[0040] S3. Based on the first bottom longitudinal wave echo, the first bottom transverse wave echo and their corresponding propagation time difference, and combined with the one-way longitudinal wave propagation time in the tested material, the one-way transverse wave propagation time in the tested material is calculated. Specifically, the formula for calculating the one-way transverse wave propagation time within the tested material is as follows: TS2=(T s −T1)+TL2; In the formula, T s T1 is the propagation time of a single bottom surface transverse wave echo; T2 is the propagation time of a single bottom surface longitudinal wave echo; TL2 is the one-way longitudinal wave propagation time within the tested material; TS2 is the one-way transverse wave propagation time within the tested material.

[0041] Specifically, the total time T of a single bottom surface shear wave echo is... s By subtracting the total time T1 of the bottom longitudinal wave echo, the propagation time TL1 from the two probes to the upper surface of the material can be eliminated, resulting in the relationship T. s −T1=TS2−TL2; Rearranging the above equations, the final solution yields the one-way transverse wave propagation time TS2 inside the measured material, corresponding to the formula TS2=(T s −T1)+TL2.

[0042] S4. Calculate the transverse wave velocity of the material under test based on the thickness of the material and the one-way transverse wave propagation time within the material.

[0043] Specifically, the formula for calculating the transverse wave velocity of the tested material is as follows: Cs=H / TS2; In the formula, H is the thickness of the material being tested; TS2 is the one-way transverse wave propagation time within the material being tested; and Cs is the transverse wave velocity of the material being tested.

[0044] Specifically, the transverse wave velocity is calculated by dividing the thickness of the material being tested by the one-way propagation time of the transverse wave within the material. Substituting the previously calculated one-way propagation time of the transverse wave into the above formula yields the transverse wave velocity of the material being tested.

[0045] Compared with traditional measurement methods that use dedicated shear wave probes, the method of this invention has significant application advantages: For thin-walled structures (thickness < 5 mm), traditional shear wave probes are difficult to couple effectively, while the method of this invention can measure directly; for curved workpieces, traditional methods require customized probes, while the method of this invention can measure directly without special processing; for space-constrained structures, traditional shear wave probes are difficult to arrange, while the method of this invention only requires a longitudinal wave straight probe; for composite laminates, traditional methods have poor signal stability, while the method of this invention effectively enhances measurement stability through multi-echo analysis; for online inspection on production lines, traditional methods require frequent switching of multiple probes, while the method of this invention only requires a single longitudinal wave straight probe to complete all measurements, significantly improving inspection efficiency and applicability.

[0046] The method for testing transverse wave sound velocity of materials based on a longitudinal wave straight probe will now be described in detail with reference to specific embodiments.

[0047] A 6061 aluminum alloy block of known thickness was selected as the test material. A 5MHz longitudinal wave straight probe was used in conjunction with an ultrasonic acquisition card to perform contact ultrasonic testing. The test method of this invention was verified by experimental testing. The experimental configuration parameters are as follows: The material under test is a 6061 aluminum alloy test block with a nominal thickness of 20mm; the test probe is a 5MHz longitudinal wave straight probe; the probe and the test block are coupled by contact; the signal acquisition equipment is an ultrasonic acquisition card with a sampling rate of not less than 100MHz.

[0048] Step 1: Collect and record the propagation time of various bottom surface echoes.

[0049] Ultrasonic echo signals were acquired using an ultrasonic acquisition card, and the primary bottom longitudinal wave echo, secondary bottom longitudinal wave echo, and bottom mode-converted shear wave echo were identified and their corresponding propagation times were recorded. The propagation time of a single bottom longitudinal wave echo is 6.45 μs, which corresponds to the longitudinal wave's round-trip propagation path within the test block being twice the thickness. The propagation time of the secondary bottom longitudinal wave echo is 12.90 μs, which corresponds to the propagation path of the longitudinal wave within the test block, which is four times the thickness. The propagation time of the shear wave echo during bottom mode conversion is 9.85 μs. This echo propagation time does not satisfy the propagation law of integer multiples of the longitudinal wave thickness, and is a shear wave signal generated by bottom mode conversion.

[0050] Step 2: Determine the propagation time of the one-way longitudinal wave inside the aluminum alloy test block.

[0051] Extract the propagation time of the first and second bottom longitudinal wave echoes, and calculate the one-way longitudinal wave propagation time inside the test block according to the formula TL2=(T2−T1) / 2: TL2=(12.90−6.45) / 2=3.225μs.

[0052] Step 3: Determine the one-way transverse wave propagation time inside the aluminum alloy specimen.

[0053] Substituting the measured total propagation time of the mode-converted shear wave echo, the propagation time of the first bottom surface longitudinal wave echo, and the previously calculated one-way longitudinal wave propagation time into the formula TS2=(T s TS2 = (9.85 - 6.45) + 3.225 = 6.625 μs.

[0054] Step 4: Calculate the transverse wave velocity of the aluminum alloy specimen.

[0055] Using the nominal thickness of the test block of 20mm as the thickness parameter H, and combining the one-way transverse wave propagation time, the transverse wave velocity of the material is calculated according to the sound velocity formula Cs=H / TS2: CS=20mm / 6.625μs=3019m / s.

[0056] Step 5: Compare and verify the test results.

[0057] The transverse wave velocity obtained by this method is compared with the range of standard transverse wave velocities for 6061 aluminum alloy recorded in existing publicly available literature: The measured shear wave velocity of this method is 3019 m / s; the standard shear wave velocity range for 6061 aluminum alloy is 3000 m / s-3100 m / s; the measured values ​​fall within the standard range, and the overall measurement error is less than 2%, proving that the test method of this invention has high calculation accuracy and reliable results.

[0058] The test method of this invention is applied to the inspection of welded steel structure components. By measuring the transverse wave velocity at different locations in the heat-affected zone of the weld, the uniformity of the internal structure of the metal after welding is judged based on the change law of the sound velocity.

[0059] The object of this inspection was a welded joint of Q345 steel plate with an overall thickness of 12mm. The key inspection area was the heat-affected zone (HAZ) of the weld. The single longitudinal wave straight probe scheme of this invention was used to collect echo signals from three locations: the base material, the HAZ of the weld, and the center of the weld. The transverse wave velocity of each region was calculated by the algorithm.

[0060] The test results are as follows: the transverse wave velocity in the base metal region is 3230 m / s, which is used as the benchmark value for this test; the transverse wave velocity in the heat-affected zone of the weld decreases to 3120 m / s, which is lower than that in the base metal; the transverse wave velocity in the center region of the weld is 3050 m / s, which is significantly lower than the benchmark velocity in the base metal.

[0061] Experiments show that the decreasing trend of transverse wave velocity in different regions of the weld matches the material defect characteristics such as grain coarsening and residual stress concentration generated during the welding process. Therefore, the transverse wave velocity measured by this invention can be used as an effective indicator for quantitatively evaluating the material microstructure of the welded area of ​​steel structures.

[0062] Based on the aforementioned calibration experiments of aluminum alloy test blocks and on-site inspection examples of steel structure welds, it can be confirmed that this invention does not require a dedicated shear wave probe. It can accurately measure the shear wave velocity of materials using only a conventional longitudinal wave straight probe. The measured values ​​have a high degree of matching with the standard reference velocity, and the test results are stable and reliable. It has excellent engineering repeatability and a wide range of on-site applications.

[0063] like Figure 2 As shown, according to another embodiment of the present invention, a material transverse wave sound velocity testing system based on a longitudinal wave straight probe is also provided, the system comprising: The ultrasonic transceiver timing module 1 is used to couple the longitudinal wave straight probe to the surface of the material under test, transmit longitudinal wave ultrasonic signals into the interior of the material under test, receive ultrasonic echo signals, and measure the propagation time of each ultrasonic echo signal; the ultrasonic echo signals include a primary bottom longitudinal wave echo, a secondary bottom longitudinal wave echo, and a primary bottom transverse wave echo. Longitudinal wave time difference analysis module 2 is used to analyze the one-way longitudinal wave propagation time in the tested material based on the primary bottom surface longitudinal wave echo, the secondary bottom surface longitudinal wave echo and their corresponding propagation time difference. The transverse wave time difference calculation module 3 is used to calculate the one-way transverse wave propagation time in the tested material based on the first bottom longitudinal wave echo, the first bottom transverse wave echo and their corresponding propagation time difference, and combined with the one-way longitudinal wave propagation time in the tested material. The transverse wave velocity conversion module 4 is used to calculate the transverse wave velocity of the material under test based on the thickness of the material and the one-way transverse wave propagation time within the material.

[0064] In practical applications, a material transverse wave sound velocity testing system based on a longitudinal wave straight probe can also include an ultrasonic excitation and receiving unit, a longitudinal wave straight probe, a time measurement unit, a longitudinal wave propagation time analysis unit, a transverse wave propagation time calculation unit, a sound velocity calculation unit, and a result display and output unit. The ultrasonic excitation and receiving unit is used to drive the longitudinal wave straight probe to emit longitudinal wave ultrasonic signals towards the material under test and to receive ultrasonic echo signals returned from the material under test. The longitudinal wave straight probe is coupled to the surface of the material under test to generate longitudinal wave ultrasound and receive longitudinal wave echoes and transverse wave echoes generated by mode conversion. The time measurement unit is used to measure the propagation time of the received multiple bottom surface longitudinal wave echo signals and longitudinal wave-transverse wave mixed echo signals. The longitudinal wave propagation time analysis unit is used to analyze and obtain the one-way longitudinal wave propagation time inside the material based on the first bottom surface longitudinal wave echo time and the second bottom surface longitudinal wave echo time. The transverse wave propagation time calculation unit is used to calculate the transverse wave propagation time inside the material based on the time difference between the echo signal containing transverse wave components and the longitudinal wave propagation time. The sound velocity calculation unit is used to calculate and output the transverse wave sound velocity of the material based on the known thickness of the material under test and the transverse wave propagation time. The result display and output unit is used to display and output the transverse wave sound velocity test results.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe, characterized in that, The method includes the following steps: S1. Couple the longitudinal wave straight probe to the surface of the material being tested, emit longitudinal wave ultrasonic signals into the interior of the material being tested, receive ultrasonic echo signals, and measure the propagation time of each ultrasonic echo signal; the ultrasonic echo signals include a primary bottom longitudinal wave echo, a secondary bottom longitudinal wave echo, and a primary bottom transverse wave echo. S2. Based on the first bottom longitudinal wave echo, the second bottom longitudinal wave echo and their corresponding propagation time difference, the one-way longitudinal wave propagation time in the tested material is obtained analytically. S3. Based on the first bottom longitudinal wave echo, the first bottom transverse wave echo and their corresponding propagation time difference, and combined with the one-way longitudinal wave propagation time in the tested material, the one-way transverse wave propagation time in the tested material is calculated. S4. Calculate the transverse wave velocity of the material under test based on the thickness of the material and the one-way transverse wave propagation time within the material.

2. The method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe according to claim 1, characterized in that, S1 includes: S11. The longitudinal wave straight probe is vertically placed on the surface of the material to be tested, and longitudinal wave ultrasonic signals are emitted to the material to be tested through the coupling medium. S12. Receive the ultrasonic echo signal returned after reflection and mode conversion of the bottom surface inside the material being tested, and identify the first bottom longitudinal wave echo, the second bottom longitudinal wave echo and the first bottom transverse wave echo from the ultrasonic echo signal. S13. The propagation time of the first bottom longitudinal wave echo, the second bottom longitudinal wave echo, and the first bottom transverse wave echo were measured respectively.

3. The method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe according to claim 2, characterized in that, The propagation time of the longitudinal wave echo on the bottom surface includes: the one-way propagation time of the longitudinal wave ultrasonic signal from the longitudinal wave probe to the upper surface of the material under test, the propagation time of the longitudinal wave ultrasonic signal traveling back and forth once along the thickness direction inside the material under test, and the one-way propagation time of the longitudinal wave ultrasonic signal returning from the upper surface of the material under test to the longitudinal wave probe.

4. The method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe according to claim 2, characterized in that, The secondary bottom longitudinal wave echo propagation time includes: the one-way propagation time of the longitudinal wave ultrasonic signal from the longitudinal wave straight probe to the upper surface of the material under test, the propagation time of the longitudinal wave ultrasonic signal traveling back and forth twice along the thickness direction inside the material under test, and the one-way propagation time of the longitudinal wave ultrasonic signal returning from the upper surface of the material under test to the longitudinal wave straight probe.

5. The method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe according to claim 2, characterized in that, The propagation path of the first bottom shear wave echo is as follows: the longitudinal wave ultrasonic signal is emitted from the longitudinal wave straight probe, enters the interior of the material under test through the upper surface of the material under test, and propagates along the thickness direction to the bottom surface of the material under test. A mode conversion occurs on the bottom surface of the material under test to generate a shear wave. The shear wave returns to the upper surface of the material under test along the thickness direction of the material under test, forming a first bottom shear wave echo, which is received by the longitudinal wave straight probe.

6. The method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe according to claim 5, characterized in that, The propagation time of the bottom surface transverse wave echo includes: the round-trip propagation time of the longitudinal wave ultrasonic signal between the longitudinal wave straight probe and the upper surface of the material under test, the propagation time of the longitudinal wave ultrasonic signal propagating one way along the thickness direction inside the material under test to the bottom surface, and the propagation time of the transverse wave generated by the bottom surface mode conversion returning one way along the thickness direction inside the material under test to the upper surface.

7. The method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe according to claim 1, characterized in that, The formula for calculating the one-way longitudinal wave propagation time within the tested material is: TL2=(T2−T1) / 2; In the formula, T1 is the propagation time of the first longitudinal wave echo from the bottom surface; T2 is the propagation time of the second longitudinal wave echo from the bottom surface; and TL2 is the one-way longitudinal wave propagation time within the material being tested.

8. The method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe according to claim 1, characterized in that, The formula for calculating the one-way transverse wave propagation time within the tested material is: TS2=(T s −T1)+TL2; In the formula, T s T1 is the propagation time of a single bottom surface transverse wave echo; T2 is the propagation time of a single bottom surface longitudinal wave echo; TL2 is the one-way longitudinal wave propagation time within the tested material; TS2 is the one-way transverse wave propagation time within the tested material.

9. The method for testing the transverse wave velocity of materials based on a longitudinal wave straight probe according to claim 1, characterized in that, The formula for calculating the transverse wave velocity of the tested material is: Cs=H / TS2; In the formula, H is the thickness of the material being tested; TS2 is the one-way transverse wave propagation time within the material being tested; Cs is the transverse wave velocity of the material being tested.

10. A material transverse wave velocity testing system based on a longitudinal wave straight probe, used to implement the material transverse wave velocity testing method based on a longitudinal wave straight probe as described in any one of claims 1-9, characterized in that, The system includes: An ultrasonic transceiver timing module is used to couple a longitudinal wave straight probe to the surface of the material under test, transmit longitudinal wave ultrasonic signals into the interior of the material under test, receive ultrasonic echo signals, and measure the propagation time of each ultrasonic echo signal; the ultrasonic echo signals include a primary bottom longitudinal wave echo, a secondary bottom longitudinal wave echo, and a primary bottom transverse wave echo. The longitudinal wave time difference analysis module is used to analyze the one-way longitudinal wave propagation time in the tested material based on the primary bottom surface longitudinal wave echo, the secondary bottom surface longitudinal wave echo and their corresponding propagation time difference. The transverse wave time difference calculation module is used to calculate the one-way transverse wave propagation time in the tested material based on the first bottom surface longitudinal wave echo, the first bottom surface transverse wave echo and their corresponding propagation time difference, and combined with the one-way longitudinal wave propagation time in the tested material. The transverse wave velocity conversion module is used to calculate the transverse wave velocity of the tested material based on the thickness of the tested material and the one-way transverse wave propagation time within the tested material.

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