An ultrasonic shear wave detection system for the stress state of a thin-walled concrete structure

Abstract

The present invention provides an ultrasonic shear wave detection system for the stress state of a thin-walled concrete structure, comprising: a transmitting end, for converting a first electrical signal into a corresponding first ultrasonic signal, and emitting the first ultrasonic signal from one side of each selected test position of the thin-walled concrete to be tested into the thin-walled concrete to be tested; a receiving end, for receiving a second ultrasonic signal emitted from the other side of each selected test position of the thin-walled concrete to be tested, and converting the second ultrasonic signal into a corresponding second electrical signal, and calculating the structural stress of the thin-walled concrete to be tested based on the first ultrasonic signal and the second ultrasonic signal; the system is used to solve the problems of poor material uniformity, high ultrasonic signal loss, and large stress measurement error when applying traditional ultrasonic methods to concrete stress testing, thereby improving the accuracy of stress testing and accurately measuring the actual stress state of thin-walled components such as reinforced concrete beam flanges and webs.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete structure safety detection and evaluation, and in particular to an ultrasonic shear wave detection system for stress state of thin-walled concrete structures. Background Art

[0002] At present, the stress state of concrete structures is an important indicator for the detection and evaluation of structural safety. Stress measurement methods are divided into two categories: destructive methods and non-destructive methods. Non-destructive methods are divided into ray diffraction methods, magnetic methods, acoustic elastic methods, etc. according to the detection means. The acoustic elastic method is very similar to the photoelastic method. It uses the slight changes in the ultrasonic wave velocity in the elastic medium caused by the influence of stress to measure the average stress of the ultrasonic wave propagation path. The acoustic elastic effect was first proposed by S. Oka. Based on the finite deformation theory, DS Hughes and JL Kelly established the relationship between the velocity and stress when ultrasonic waves propagate in materials, laying the theoretical foundation for ultrasonic stress measurement. It has attracted attention because it does not cause any damage to the object being tested. In recent years, it has been widely used in residual stress detection of metal materials and flaw detection of composite materials.

[0003] Because concrete is a complex mixture of materials, ultrasonic stress testing is subject to numerous influencing factors, including high signal loss and large parameter errors. This poses challenges in terms of accuracy and applicability. For example, ultrasonic testing in nondestructive testing and residual stress testing is impractical in concrete due to poor material uniformity and low absolute stress values, resulting in large stress measurement errors.

[0004] The application of ultrasonic methods in concrete stress testing is hampered by challenges such as poor material uniformity, high ultrasonic signal loss, and large stress measurement errors. This invention provides an ultrasonic shear wave stress state detection system for thin-walled concrete structures to address these issues. This improves stress testing accuracy and standardizes the testing method. Summary of the Invention

[0005] The present invention provides an ultrasonic shear wave detection system for the stress state of thin-walled concrete structures, which is used to solve the problems of poor material uniformity, high ultrasonic signal loss, and large stress measurement errors when applying traditional ultrasonic methods to concrete stress testing, thereby improving the accuracy of stress testing and procedurally standardizing the testing method. The testing process is simple, the testing method is clear, and the actual working stress state of thin-walled components such as reinforced concrete beam flanges and webs can be accurately measured.

[0006] The present invention provides an ultrasonic shear wave detection system for stress state of thin-walled concrete structures, comprising:

[0007] a transmitting end, configured to convert the first electrical signal into a corresponding first ultrasonic signal, and transmit the first ultrasonic signal from one side of each selected test position of the thin-walled concrete to be tested to the thin-walled concrete to be tested;

[0008] The receiving end is used to receive a second ultrasonic signal emitted from the other side of each selected test position of the thin-walled concrete to be tested, and convert the second ultrasonic signal into a corresponding second electrical signal, and calculate the structural stress of the thin-walled concrete to be tested based on the first electrical signal and the second electrical signal.

[0009] Preferably, the transmitting end includes:

[0010] A pulse signal source, used to generate a preset pulse electrical signal;

[0011] a signal amplifier, configured to amplify the preset pulse electrical signal according to a preset amplification factor to obtain a corresponding first electrical signal;

[0012] The first shear wave ultrasonic transducer is used to convert the first electrical signal into a corresponding first ultrasonic signal, and emit the first ultrasonic signal into the thin-walled concrete to be tested from one side of each selected test position of the thin-walled concrete to be tested.

[0013] Preferably, the first shear wave ultrasonic transducer comprises:

[0014] a first transducer unit, configured to convert the first electrical signal into a corresponding first ultrasonic signal;

[0015] The first shear wave ultrasonic transducer probe is used to emit the first ultrasonic signal into the thin-walled concrete to be tested from one side of each selected test position of the thin-walled concrete to be tested.

[0016] Preferably, the receiving end includes:

[0017] a second shear wave ultrasonic transducer, configured to receive a second ultrasonic signal emitted from the other side of each selected test position of the thin-walled concrete to be tested, and convert the second ultrasonic signal into a corresponding second electrical signal;

[0018] a signal oscilloscope, configured to receive and display the first electrical signal and the second electrical signal;

[0019] A data storage processor is used to receive and store the first electrical signal and the second electrical signal, and obtain the ultrasonic propagation travel time based on comparing the first wave acoustic time of the first electrical signal and the second electrical signal, and calculate the structural stress of the thin-wall concrete to be measured based on the ultrasonic travel time.

[0020] Preferably, the second shear wave ultrasonic transducer comprises:

[0021] a second shear wave ultrasonic transducer probe, configured to receive a second ultrasonic signal emitted from the other side of each selected test position of the thin-walled concrete to be tested;

[0022] The second transducer unit is configured to convert the second ultrasonic signal into a corresponding second electrical signal.

[0023] Preferably, the first shear wave transducer probe and the second shear wave ultrasonic transducer probe are arranged on the slide rail tooling in a probe-to-probe transmission manner, the first shear wave ultrasonic transducer probe is fixed to the slide rail tooling, and the second shear wave ultrasonic transducer probe slides along the tooling track;

[0024] The distances between the first shear wave ultrasonic transducer probe and the second shear wave ultrasonic transducer probe are measured by the length scale.

[0025] Preferably, the data storage processor includes:

[0026] Step 1: Determine the wing plate position that meets the zero boundary stress condition at the beam end, and place the combined ultrasonic transducers on both sides of the wing plate position for measurement;

[0027] Step 2: Synchronously rotate the first shear wave transducer probe and the second shear wave ultrasonic transducer probe based on the angle rotation gear, and determine the first shear wave velocity with mutually perpendicular sensor polarization directions based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. and the second shear wave velocity

[0028] Step 3: Based on the first shear wave velocity and the second shear wave velocity Calculate the first average wave velocity

[0029]

[0030] Where, is the first average wave velocity;

[0031] Step 4: Determine the target structure stress test position, and place the combined ultrasonic transducers on both sides of the target structure stress test position;

[0032] Step 5: Synchronously rotate the first shear wave transducer probe and the second shear wave ultrasonic transducer probe based on the angle rotation gear according to the preset interval degree until the sensor polarization direction on the second shear wave ultrasonic transducer is parallel to the stress direction, and then determine the maximum shear wave velocity v based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. z1, at the same time, record the first rotation angle on the angle scale;

[0033] Step 6: Determine a first rotation angle range based on the first rotation angle, and start from the lower limit of the first rotation angle range according to a preset interval, and synchronously rotate the first shear wave transducer probe and the second shear wave ultrasonic transducer probe based on the angle rotation gear until the sensor polarization direction on the second shear wave ultrasonic transducer is perpendicular to the stress direction. Then, determine the minimum shear wave velocity v based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. z2 ;

[0034] Step 7: Based on the maximum shear wave velocity v z1 and the minimum shear wave velocity v z2 , calculate the second average wave velocity v T :

[0035]

[0036] Where, v T is the second mean wave velocity;

[0037] Step 8: Based on the first average wave velocity, the second average wave velocity and the maximum shear wave velocity v z1 and the minimum shear wave velocity v z2 , calculate the structural stress at the target structural stress test location:

[0038]

[0039]

[0040] Where, σ1 and σ1 are the v z1 and v z2 Polarization stress, σ1 and σ1 are in MPa, v T is the second mean wave velocity, is the first average wave velocity, C T is the shear wave acoustic elastic coefficient of the thin-walled concrete to be tested at the stress test position of the target structure, and C T The unit is (MPa) -1 , v z1 is the maximum shear wave velocity, v z2 is the minimum vertical shear wave velocity, C A is the shear wave acoustic elastic birefringence coefficient of the thin-walled concrete to be tested at the stress test position of the target structure, and C A The unit is (MPa) -1 .

[0041] Preferably, the maximum shear wave velocity v is determined based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. z1 ,include:

[0042] a spectrum naming subunit, configured to output a first signal spectrum of the first electrical signal and a second signal spectrum of the second electrical signal when the angular rotary gear is at the first rotation angle, use the first signal spectrum as a reference spectrum, and use the second signal spectrum as a spectrum to be corrected corresponding to the first reference spectrum;

[0043] a signal denoising subunit, configured to denoise the signal spectrum graph corresponding to the reference spectrum graph to obtain a corresponding denoised spectrum graph;

[0044] a fourth calculation subunit, configured to calculate a first peak average value and a first trough average value corresponding to the denoised spectrum graph, and simultaneously calculate a second peak average value and a second trough average value corresponding to the spectrum graph to be corrected;

[0045] a fifth calculation subunit, configured to calculate a first difference between the first peak average value and the second peak average value, a second difference between the first trough average value and the second trough average value, and a third difference between the first peak average value and the first trough average value, and calculate a vertical scaling factor corresponding to the to-be-corrected spectrum graph based on a first ratio of the first difference to the third difference and a second ratio of the second difference to the third difference;

[0046] a frequency determination subunit, configured to determine all zero-crossing points in the denoised spectrum to obtain a corresponding first zero-crossing point sequence, and determine a corresponding first vibration frequency based on the first zero-crossing point sequence; and simultaneously determine all zero-crossing points in the to-be-corrected spectrum to obtain a corresponding second zero-crossing point sequence, and determine a corresponding second vibration frequency based on the second zero-crossing point sequence;

[0047] a sixth calculation subunit, configured to calculate a corresponding horizontal scaling factor based on the first vibration frequency and the second vibration frequency;

[0048] a spectrum fitting subunit, configured to fit a corresponding fitting signal spectrum graph based on the vertical scaling factor, the horizontal scaling factor, and the denoised spectrum graph;

[0049] A local correction subunit, configured to perform local correction on the to-be-corrected spectrum graph based on the fitted signal spectrum graph to obtain a corresponding corrected spectrum graph;

[0050] a spectrum output subunit, configured to use the denoised spectrum corresponding to the reference spectrum as the corresponding first corrected spectrum, and use the corrected spectrum corresponding to the first spectrum to be corrected as the corresponding second corrected spectrum;

[0051] The velocity determination subunit is configured to obtain the current ultrasonic propagation travel time based on the first wave acoustic time of the first correction spectrum and the second correction spectrum, and determine the maximum shear wave velocity v based on the current ultrasonic propagation travel time. z1 .

[0052] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0053] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0055] Figure 1 This is a schematic structural diagram of an ultrasonic shear wave detection system for stress state of a thin-walled concrete structure according to an embodiment of the present invention;

[0056] Figure 2 This is a schematic diagram of a transmitting end in an embodiment of the present invention;

[0057] Figure 3 Schematic diagram of a first shear wave ultrasonic transducer according to an embodiment of the present invention;

[0058] Figure 4 Schematic diagram of a receiving end in an embodiment of the present invention;

[0059] Figure 5 Schematic diagram of a second shear wave ultrasonic transducer according to an embodiment of the present invention;

[0060] Figure 6 Schematic diagram of a signal correction subunit in an embodiment of the present invention;

[0061] Figure 7 Schematic diagram of a fastening solution for a combined shear wave ultrasonic transducer according to an embodiment of the present invention;

[0062] Figure 8 This is a front view of a combined shear wave ultrasonic transducer test fixture solution in an embodiment of the present invention;

[0063] Figure 9 A side view of a combined shear wave ultrasonic transducer test fixture solution according to an embodiment of the present invention;

[0064] Figure 10 A top view of a combined shear wave ultrasonic transducer test fixture solution according to an embodiment of the present invention;

[0065] Figure 11 A perspective view of a stress test on reinforced concrete beams using a contact transmission method according to an embodiment of the present invention;

[0066] Figure 12 Schematic diagram of a wing plate test for a reinforced concrete beam stress test using a contact transmission method according to an embodiment of the present invention;

[0067] Figure 13 This is a schematic diagram of an enlarged structure of a wing plate position in a thin-walled concrete according to an embodiment of the present invention;

[0068] Figure 14 A schematic diagram of a sensor in an embodiment of the present invention showing that the shear wave velocity is the largest when the polarization direction is parallel to the stress direction;

[0069] Figure 15 Schematic diagram of a sensor with a minimum shear wave velocity when the polarization direction is perpendicular to the stress direction in an embodiment of the present invention. DETAILED DESCRIPTION

[0070] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0071] The present invention provides an ultrasonic shear wave detection system for stress state of thin-walled concrete structure, referring to Figure 1 、 11 , 12, including:

[0072] a transmitting end, configured to convert the first electrical signal into a corresponding first ultrasonic signal, and transmit the first ultrasonic signal from one side of each selected test position of the thin-walled concrete to be tested to the thin-walled concrete to be tested;

[0073] The receiving end is used to receive a second ultrasonic signal emitted from the other side of each selected test position of the thin-walled concrete to be tested, and convert the second ultrasonic signal into a corresponding second electrical signal, and calculate the structural stress of the thin-walled concrete to be tested based on the first electrical signal and the second electrical signal.

[0074] In this embodiment, the first electrical signal is an electrical signal obtained by amplifying a pulse electrical signal generated by a pulse signal source through a signal amplifier.

[0075] In this embodiment, the first ultrasonic signal is a corresponding ultrasonic signal converted from the first electrical signal by the first shear wave ultrasonic transducer.

[0076] In this embodiment, the selected test positions are the wing plate and the web plate. Figure 11 and 12 , Figure 14 13, 14, and 15 are the selected test positions. 13 is the selected mid-span flange position, 14 is the flange position that satisfies zero boundary stress, 15 is the selected web position, 11 is the mid-span section of the thin-walled concrete to be tested, and 12 is the beam end section. Figure 12 The 16 in the figure is the reinforced concrete beam.

[0077] In this embodiment, the thin-walled concrete to be tested is the thin-walled concrete in the structural stress state to be tested in the present invention.

[0078] In this embodiment, the second ultrasonic signal is the ultrasonic signal emitted after the first ultrasonic signal penetrates each preset selected test position of the thin-walled concrete to be tested.

[0079] In this embodiment, the second electrical signal is the electrical signal converted from the second ultrasonic signal.

[0080] In this embodiment, the ultrasonic shear wave detection system for stress state of thin-walled concrete structures includes: a pulse signal source, a signal amplifier, a channel selection switch, a combined shear wave ultrasonic transducer, a signal oscilloscope, and a data storage processor. The system workflow is as follows:

[0081] Step 1: The pulse signal source generates a pulse electrical signal, which is amplified by the signal amplifier to obtain a first electrical signal, and the first electrical signal is transmitted to the combined shear wave ultrasonic transducer on one side, and simultaneously transmitted to the signal oscilloscope and the data storage processor for displaying and storing the first electrical signal, respectively;

[0082] Step 2: The combined ultrasonic transducer on one side converts the first electrical signal into an ultrasonic wave, which is transmitted through the concrete to the combined ultrasonic transducer on the other side and converted into a second electrical signal. The second electrical signal is simultaneously transmitted to the signal oscilloscope and the data storage processor for displaying and storing the second electrical signal, respectively.

[0083] Step 3: The data storage processor compares the first wave acoustic time of the first electrical signal and the second electrical signal to obtain the ultrasonic propagation travel time;

[0084] Step 4: Complete the current state test and proceed to the next level stress state test of concrete.

[0085] The beneficial effects of the above technology are: it solves the problems of poor material uniformity, high ultrasonic signal loss, and large stress measurement errors when applying traditional ultrasonic methods to concrete stress testing, thereby improving the accuracy of stress testing and standardizing the testing methods. The testing process is simple and the testing method is clear, which can accurately measure the actual structural stress state of thin-walled components such as reinforced concrete beam flanges and webs.

[0086] Example 2:

[0087] On the basis of embodiment 1, the transmitting end, referring to Figure 2 and 7 ,include:

[0088] A pulse signal source, used to generate a preset pulse electrical signal;

[0089] a signal amplifier, configured to amplify the preset pulse electrical signal according to a preset amplification factor to obtain a corresponding first electrical signal;

[0090] The first shear wave ultrasonic transducer is used to convert the first electrical signal into a corresponding first ultrasonic signal, and emit the first ultrasonic signal into the thin-walled concrete to be tested from one side of each selected test position of the thin-walled concrete to be tested.

[0091] In this embodiment, the preset pulse electrical signal is set according to actual conditions.

[0092] In this embodiment, reference Figure 7 A transducer slot 7 is provided between the first shear wave ultrasonic transducer 6 and the second shear wave ultrasonic transducer 6 .

[0093] The beneficial effects of the above technology are: completing the process of ultrasonic wave injection from one side of the thin-walled concrete to be tested, and providing a basis for subsequent detection of the structural stress state of the thin-walled concrete to be tested based on ultrasonic shear waves.

[0094] Example 3:

[0095] On the basis of Example 2, the first shear wave ultrasonic transducer, referring to Figure 3 ,include:

[0096] a first transducer unit, configured to convert the first electrical signal into a corresponding first ultrasonic signal;

[0097] The first shear wave ultrasonic transducer probe is used to emit the first ultrasonic signal into the thin-walled concrete to be tested from one side of each selected test position of the thin-walled concrete to be tested.

[0098] The beneficial effects of the above technology are: energy conversion from an electrical signal to an ultrasonic signal is completed based on the first transducer unit, and the emission process of the first ultrasonic signal is completed based on the first shear wave ultrasonic transducer probe.

[0099] Example 4:

[0100] On the basis of Example 3, the receiving end, referring to Figure 4 and 7 ,include:

[0101] a second shear wave ultrasonic transducer, configured to receive a second ultrasonic signal emitted from the other side of each selected test position of the thin-walled concrete to be tested, and convert the second ultrasonic signal into a corresponding second electrical signal;

[0102] a signal oscilloscope, configured to receive and display the first electrical signal and the second electrical signal;

[0103] A data storage processor is used to receive and store the first electrical signal and the second electrical signal, and obtain the ultrasonic propagation travel time based on comparing the first wave acoustic time of the first electrical signal and the second electrical signal, and calculate the structural stress of the thin-wall concrete to be measured based on the ultrasonic travel time.

[0104] In this embodiment, reference Figure 7 A transducer slot 7 is provided between the first shear wave ultrasonic transducer 6 and the second shear wave ultrasonic transducer 6 .

[0105] The beneficial effects of the above technology are: based on the second shear wave ultrasonic transducer, the transduction of ultrasonic signals into electrical signals is realized; based on the signal oscilloscope, the visualization function of electrical signals is realized; based on the data storage processor, the storage and processing of electrical signals are realized, and the structural stress of the thin-wall concrete to be tested is calculated.

[0106] Example 5:

[0107] On the basis of Example 4, the second shear wave ultrasonic transducer, referring to Figure 5 ,include:

[0108] a second shear wave ultrasonic transducer probe, configured to receive a second ultrasonic signal emitted from the other side of each selected test position of the thin-walled concrete to be tested;

[0109] The second transducer unit is configured to convert the second ultrasonic signal into a corresponding second electrical signal.

[0110] The beneficial effects of the above technology are: based on the second shear wave ultrasonic transducer probe, it is possible to receive the ultrasonic signal emitted from the other side of each preset selected test position of the thin-walled concrete to be tested, and based on the second transducer unit, it is possible to convert the ultrasonic signal into a corresponding electrical signal.

[0111] Example 6:

[0112] Based on Example 5, Figure 6 and 7 To 12, the first shear wave transducer probe and the second shear wave ultrasonic transducer probe are arranged on the slide rail tooling (reference Figures 10 to 15 ), the first shear wave ultrasonic transducer probe is fixed to the slide rail fixture, and the second shear wave ultrasonic transducer probe slides along the fixture track;

[0113] The distances between the first shear wave ultrasonic transducer probe and the second shear wave ultrasonic transducer probe are measured by the length scale 8 (a length fixing bolt 10 is provided on the length scale 8).

[0114] In this embodiment, the first shear wave transducer probe and the second shear wave ultrasonic transducer probe are precisely rotated within a range of 0° to 135° to capture the birefringence effect caused by stress of ultrasonic waves and obtain more accurate vibration energy differences.

[0115] In this embodiment, the combined shear wave ultrasonic transducer solution is:

[0116] Two shear wave transducer probes are arranged opposite each other using a sliding fixture and fastener 5, one of which is fixed and the other can be adjusted and fixed along the longitudinal direction of the sliding fixture. The distance between the probes is measured by a length ruler 8;

[0117] The primary vibration directions of the first and second shear wave ultrasonic transducer probes are aligned, and both can be precisely rotated and fixed within a range of 0° to 135°. Angle gears 3 (fixed to fasteners 5 by angle fixing bolts 4) adjust the rotation angle, which is measured by angle scale 9. This ensures that the primary vibration directions of the shear wave transducers are aligned after rotation, thereby obtaining the excitation and reception of ultrasonic waves in two perpendicular directions in the concrete.

[0118] The elastic rubber pad 1 between the transducer and the fastener 5 isolates vibration, and through the slot, the transducer can only slide but not rotate in the inner cavity of the fastener 5. The spring 2 at the bottom of the transducer presses the contact surface between the transducer and the concrete.

[0119] The beneficial effects of the above technology are as follows: This embodiment describes the fastening and tooling method of the shear wave combined ultrasonic transducer to the test probe and the transmission test arrangement scheme with adjustable ultrasonic probe angle and measurable spacing, which provides a basis for realizing the detection of the structural stress state of the thin-walled concrete to be tested based on ultrasonic shear waves.

[0120] Example 7:

[0121] On the basis of embodiment 6, the data storage processor, referring to Figure 7 、 11, 13, 14, 15, including:

[0122] Step 1: Determine the wing plate position that meets the zero boundary stress condition at the beam end, and place the combined ultrasonic transducers on both sides of the wing plate position for measurement;

[0123] Step 2: Synchronously rotate the first shear wave transducer probe and the second shear wave ultrasonic transducer probe based on the angle rotation gear, and determine the first shear wave velocity with mutually perpendicular sensor polarization directions based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. and the second shear wave velocity

[0124] Step 3: Based on the first shear wave velocity and the second shear wave velocity Calculate the first average wave velocity

[0125]

[0126] Where, is the first average wave velocity;

[0127] Step 4: Determine the target structure stress test position, and place the combined ultrasonic transducers on both sides of the target structure stress test position;

[0128] Step 5: Synchronously rotate the first shear wave transducer probe and the second shear wave ultrasonic transducer probe based on the angle rotation gear according to the preset interval degree until the sensor polarization direction on the second shear wave ultrasonic transducer is parallel to the stress direction, and then determine the maximum shear wave velocity v based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. z1 , at the same time, record the first rotation angle on the angle scale;

[0129] Step 6: Determine a first rotation angle range based on the first rotation angle, and start from the lower limit of the first rotation angle range according to a preset interval, and synchronously rotate the first shear wave transducer probe and the second shear wave ultrasonic transducer probe based on the angle rotation gear until the sensor polarization direction on the second shear wave ultrasonic transducer is perpendicular to the stress direction. Then, determine the minimum shear wave velocity v based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. z2 ;

[0130] Step 7: Based on the maximum shear wave velocity v z1 and the minimum shear wave velocity v z2 , calculate the second average wave velocity v T :

[0131]

[0132] Where, v T is the second mean wave velocity;

[0133] Step 8: Based on the first average wave velocity, the second average wave velocity and the maximum shear wave velocity v z1 and the minimum shear wave velocity v z2 , calculate the structural stress at the target structural stress test location:

[0134]

[0135]

[0136] Where, σ1 and σ1 are the v z1 and v z2 Polarization stress, σ1 and σ1 are in MPa (i.e., megapascals), v T is the second mean wave velocity, is the first average wave velocity, C T is the shear wave acoustic elastic coefficient of the thin-walled concrete to be tested at the stress test position of the target structure, and C T The unit is (MPa) -1 (i.e., minus one megapascal), v z1 is the maximum shear wave velocity, v z2 is the minimum vertical shear wave velocity, C A is the shear wave acoustic elastic birefringence coefficient of the thin-walled concrete to be tested at the stress test position of the target structure, and C A The unit is (MPa) -1 .

[0137] In this embodiment, the wing plate position that satisfies the zero boundary stress condition at the beam end is determined as Figure 11 Position 14 in the Figure 13 The position in Figure 11 (enlarged structure of position 14 in the figure).

[0138] In this embodiment, the preset interval degree is, for example, 5 degrees.

[0139] In this embodiment, the first shear wave velocity That is, when testing the wing position that meets the zero boundary stress condition at the beam end, the shear wave velocity corresponding to one of the mutually perpendicular sensor polarization directions.

[0140] In this embodiment, the second shear wave velocity That is, when testing the wing position that meets the zero boundary stress condition at the beam end, the shear wave velocity corresponding to the other polarization direction of the mutually perpendicular sensor polarization directions.

[0141] In this embodiment, the target structure stress test position is, for example, Figure 11 Position 13 (mid-span flange) or Position 15 (web) in the.

[0142] In this embodiment, reference Figure 14 , maximum shear wave velocity v z1 That is, when measuring the stress test position of the target structure, when the polarization direction of the sensor on the second shear wave ultrasonic transducer is parallel to the stress direction, the wave velocity value of the ultrasonic wave at the stress test position of the target structure is determined based on the current ultrasonic propagation path of the first ultrasonic signal and the second ultrasonic signal.

[0143] In this embodiment, the first rotation angle is the angle displayed by the angle scale when the sensor polarization direction on the second shear wave ultrasonic transducer is parallel to the stress direction when measuring the stress test position of the target structure.

[0144] In this embodiment, the first rotation angle range is a range formed by adding 80 to 110 degrees to the first rotation angle. For example, if the first rotation angle is 10 degrees, the first rotation angle range is 90 to 120 degrees.

[0145] In this embodiment, the lower limit value of the first rotation angle range is the lower limit value of the first rotation angle range.

[0146] In this embodiment, reference Figure 15 , minimum shear wave velocity v z2 That is, when measuring the stress test position of the target structure, when the polarization direction of the sensor on the second shear wave ultrasonic transducer is perpendicular to the stress direction, the wave velocity value of the ultrasonic wave at the stress test position of the target structure is determined based on the current ultrasonic propagation path of the first ultrasonic signal and the second ultrasonic signal.

[0147] The beneficial effects of the above technology are as follows: based on the synchronous rotation of the first shear wave transducer probe and the second shear wave transducer probe, the maximum shear wave velocity and the minimum shear wave velocity can be accurately retrieved, thereby making the calculated structural stress at the target structural stress test position more accurate. Based on the maximum shear wave velocity when the polarization direction of the sensor on the second shear wave ultrasonic transducer at the wing plate position that meets the zero boundary stress condition of the beam end is parallel to the stress direction and the minimum shear wave velocity when the polarization direction of the sensor on the second shear wave ultrasonic transducer is perpendicular to the stress direction, and the maximum shear wave velocity when the polarization direction of the sensor on the second shear wave ultrasonic transducer at the target structural stress test position is parallel to the stress direction and the minimum shear wave velocity when the polarization direction of the sensor on the second shear wave ultrasonic transducer is perpendicular to the stress direction, combined with the material shear wave acoustic elastic coefficient and the material shear wave acoustic elastic birefringence coefficient at the target structural stress test position, the actual structural stress state of thin-walled concrete can be accurately calculated, solving the problems of poor material uniformity, high ultrasonic signal loss, and large stress measurement error when the traditional ultrasonic method is applied to concrete stress testing, thereby improving the accuracy of stress testing, procedurally standardizing the testing method, and simplifying the testing process.

[0148] Example 8:

[0149] On the basis of Example 7, the maximum shear wave velocity v is determined based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. z1 ,refer to Figure 6 ,include:

[0150] a spectrum naming subunit, configured to output a first signal spectrum of the first electrical signal and a second signal spectrum of the second electrical signal when the angular rotary gear is at the first rotation angle, use the first signal spectrum as a reference spectrum, and use the second signal spectrum as a spectrum to be corrected corresponding to the first reference spectrum;

[0151] a signal denoising subunit, configured to denoise the signal spectrum graph corresponding to the reference spectrum graph to obtain a corresponding denoised spectrum graph;

[0152] a fourth calculation subunit, configured to calculate a first peak average value and a first trough average value corresponding to the denoised spectrum graph, and simultaneously calculate a second peak average value and a second trough average value corresponding to the spectrum graph to be corrected;

[0153] a fifth calculation subunit, configured to calculate a first difference between the first peak average value and the second peak average value, a second difference between the first trough average value and the second trough average value, and a third difference between the first peak average value and the first trough average value, and calculate a vertical scaling factor corresponding to the to-be-corrected spectrum graph based on a first ratio of the first difference to the third difference and a second ratio of the second difference to the third difference;

[0154] a frequency determination subunit, configured to determine all zero-crossing points in the denoised spectrum to obtain a corresponding first zero-crossing point sequence, and determine a corresponding first vibration frequency based on the first zero-crossing point sequence; and simultaneously determine all zero-crossing points in the to-be-corrected spectrum to obtain a corresponding second zero-crossing point sequence, and determine a corresponding second vibration frequency based on the second zero-crossing point sequence;

[0155] a sixth calculation subunit, configured to calculate a corresponding horizontal scaling factor based on the first vibration frequency and the second vibration frequency;

[0156] a spectrum fitting subunit, configured to fit a corresponding fitting signal spectrum graph based on the vertical scaling factor, the horizontal scaling factor, and the denoised spectrum graph;

[0157] A local correction subunit, configured to perform local correction on the to-be-corrected spectrum graph based on the fitted signal spectrum graph to obtain a corresponding corrected spectrum graph;

[0158] a spectrum output subunit, configured to use the denoised spectrum corresponding to the reference spectrum as the corresponding first corrected spectrum, and use the corrected spectrum corresponding to the first spectrum to be corrected as the corresponding second corrected spectrum;

[0159] The velocity determination subunit is configured to obtain the current ultrasonic propagation travel time based on the first wave acoustic time of the first correction spectrum and the second correction spectrum, and determine the maximum shear wave velocity v based on the current ultrasonic propagation travel time. z1 .

[0160] In this embodiment, the first signal spectrum diagram is a signal spectrum diagram of the first electrical signal when the angle rotary gear is rotated at a first rotation angle.

[0161] In this embodiment, the second signal spectrum diagram is a signal spectrum diagram of the second electrical signal when the angle rotary gear is rotated at the first rotation angle.

[0162] In this embodiment, the reference spectrum diagram is the first signal spectrum diagram.

[0163] In this embodiment, the frequency spectrum to be corrected is the second signal frequency spectrum.

[0164] In this embodiment, the denoised spectrum graph is a signal spectrum graph obtained by denoising the signal spectrum graph corresponding to the reference spectrum graph.

[0165] In this embodiment, the first peak average value is the average value of all peak values in the denoised spectrum graph.

[0166] In this embodiment, the first trough average value is the average value of all trough values in the denoised spectrum graph.

[0167] In this embodiment, the second peak average value is the average value of all peak values in the spectrum to be corrected.

[0168] In this embodiment, the second trough average value is the average value of all trough values in the spectrum to be corrected.

[0169] In this embodiment, the first difference is the difference between the first peak average value and the second peak average value.

[0170] In this embodiment, the second difference is the difference between the first valley average value and the second valley average value.

[0171] In this embodiment, the third difference is the difference between the first peak average value and the first valley average value.

[0172] In this embodiment, the first ratio is the ratio of the first difference to the third difference.

[0173] In this embodiment, the second ratio is the ratio of the second difference to the third difference.

[0174] In this embodiment, the vertical scaling factor is the sum of the first ratio and the second ratio.

[0175] In this embodiment, the zero-crossing point is the intersection of the signal graph and the time axis in the denoised spectrum graph.

[0176] In this embodiment, the first zero-crossing point sequence is a sequence composed of all zero-crossing points in the denoised spectrum graph.

[0177] In this embodiment, the first vibration frequency is a ratio of 1 to an average value of time differences between all two adjacent zero-crossing points included in the first zero-crossing point sequence.

[0178] In this embodiment, the second zero-crossing point sequence is a sequence composed of all zero-crossing points in the spectrum graph to be corrected.

[0179] In this embodiment, the second vibration frequency is a ratio of 1 to an average value of time differences between all two adjacent zero-crossing points included in the second zero-crossing point sequence.

[0180] In this embodiment, fitting a corresponding fitting signal spectrum diagram based on the vertical scaling factor, the horizontal scaling factor, and the denoised spectrum diagram includes:

[0181] The denoised spectrum graph is scaled vertically based on the vertical scaling factor, and then scaled horizontally based on the horizontal scaling factor to obtain the corresponding fitted signal spectrum graph.

[0182] In this embodiment, locally correcting the to-be-corrected spectrum graph based on the fitted signal spectrum graph to obtain a corresponding corrected spectrum graph includes:

[0183] Perform time sequence alignment on the fitted signal spectrum and the spectrum to be corrected to obtain the corresponding aligned spectrum;

[0184] Based on the aligned spectrum graph, the signal amplitude difference between the fitted signal spectrum graph and the spectrum graph to be corrected at each moment is determined. When the signal amplitude difference is greater than the difference threshold, the signal amplitude of the spectrum graph to be corrected at the corresponding moment is set to the average signal amplitude of the fitted signal spectrum graph and the spectrum graph to be corrected at the corresponding moment, thereby obtaining the corresponding corrected spectrum graph.

[0185] In this embodiment, the maximum shear wave velocity v is determined based on the current ultrasonic propagation travel time. z1 , that is: divide the probe distance between the first shear wave ultrasonic transducer probe and the second shear wave ultrasonic transducer probe measured by the length scale by the current ultrasonic propagation time to obtain the maximum shear wave velocity v z1 .

[0186] The beneficial effects of the above technology are: denoising the reference spectrum graph to obtain the corresponding reference denoised spectrum graph, realizing denoising of the reference spectrum graph, determining the scaling ratio between the spectrum graph to be corrected and the reference denoised spectrum graph based on the difference in peak values and trough values and the difference in zero crossing points between the spectrum graph to be corrected and the reference denoised spectrum graph, fitting a standard fitting signal spectrum graph corresponding to the spectrum graph to be corrected based on the scaling ratio, and then realizing denoising correction of the spectrum graph to be corrected based on the fitting signal spectrum graph, thereby ensuring the accuracy of the structural stress state of the thin-walled concrete to be tested based on ultrasonic shear wave detection.

[0187] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. An ultrasonic shear wave detection system for stress state of thin-walled concrete structure, characterized in that: include: A transmitting end, configured to convert the first electrical signal into a corresponding first ultrasonic signal, and transmit the first ultrasonic signal from one side of each selected test position of the thin-walled concrete to be tested to the thin-walled concrete to be tested, comprising: A pulse signal source, used to generate a preset pulse electrical signal; a signal amplifier, configured to amplify the preset pulse electrical signal according to a preset amplification factor to obtain a corresponding first electrical signal; The first shear wave ultrasonic transducer is configured to convert the first electrical signal into a corresponding first ultrasonic signal, and emit the first ultrasonic signal into the thin-walled concrete to be tested from one side of each selected test position of the thin-walled concrete to be tested, comprising: a first transducer unit, configured to convert the first electrical signal into a corresponding first ultrasonic signal; a first shear wave ultrasonic transducer probe, configured to emit the first ultrasonic signal from one side of each selected test position of the thin-walled concrete to be tested into the thin-walled concrete to be tested; A receiving end is configured to receive a second ultrasonic signal emitted from the other side of each selected test position of the thin-walled concrete to be tested, convert the second ultrasonic signal into a corresponding second electrical signal, and calculate the structural stress of the thin-walled concrete to be tested based on the first electrical signal and the second electrical signal, including: The second shear wave ultrasonic transducer is used to receive a second ultrasonic signal emitted from the other side of each selected test position of the thin-walled concrete to be tested, and convert the second ultrasonic signal into a corresponding second electrical signal, including: a second shear wave ultrasonic transducer probe, configured to receive a second ultrasonic signal emitted from the other side of each selected test position of the thin-walled concrete to be tested; a second transducer unit, configured to convert the second ultrasonic signal into a corresponding second electrical signal; a signal oscilloscope, configured to receive and display the first electrical signal and the second electrical signal; A data storage processor is configured to receive and store the first electrical signal and the second electrical signal, obtain ultrasonic propagation travel time based on a comparison of the first wave acoustic time of the first electrical signal and the second electrical signal, and calculate the structural stress of the thin-wall concrete to be measured based on the ultrasonic travel time, comprising: Step 1: Determine the wing plate position that meets the zero boundary stress condition at the beam end, and place the combined ultrasonic transducers on both sides of the wing plate position for measurement; Step 2: Synchronously rotate the first shear wave ultrasonic transducer probe and the second shear wave ultrasonic transducer probe based on the angle rotation gear, and determine the first shear wave velocity of the transducer with mutually perpendicular polarization directions based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. and the second shear wave velocity Step 3: Based on the first shear wave velocity and the second shear wave velocity Calculate the first average wave velocity Where, is the first average wave velocity; Step 4: Determine the target structure stress test position, and place the combined ultrasonic transducers on both sides of the target structure stress test position; Step 5: Synchronously rotate the first shear wave ultrasonic transducer probe and the second shear wave ultrasonic transducer probe based on the angle rotation gear according to the preset interval degree until the sensor polarization direction on the second shear wave ultrasonic transducer is parallel to the stress direction, and then determine the maximum shear wave velocity v based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. z1 , at the same time, record the first rotation angle on the angle scale; Step 6: Determine a first rotation angle range based on the first rotation angle, and start from the lower limit of the first rotation angle range according to a preset interval, and synchronously rotate the first shear wave ultrasonic transducer probe and the second shear wave ultrasonic transducer probe based on the angle rotation gear until the sensor polarization direction on the second shear wave ultrasonic transducer is perpendicular to the stress direction. Then, determine the minimum shear wave velocity v based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal. z2 ; Step 7: Based on the maximum shear wave velocity v z1 and the minimum shear wave velocity v z2 , calculate the second average wave velocity v T : Where, v T is the second mean wave velocity; Step 8: Based on the first average wave velocity, the second average wave velocity and the maximum shear wave velocity v z1 and the minimum shear wave velocity v z2 , calculate the structural stress at the target structural stress test location: Where, σ1 and σ1 are the v z1 and v z2 Polarization stress, σ1 and σ1 are in MPa, v T is the second mean wave velocity, is the first average wave velocity, C T is the shear wave acoustic elastic coefficient of the thin-walled concrete to be tested at the stress test position of the target structure, and C T The unit is (MPa) -1 , v z1 is the maximum shear wave velocity, v z2 is the minimum vertical shear wave velocity, C A is the shear wave acoustic elastic birefringence coefficient of the thin-walled concrete to be tested at the stress test position of the target structure, and C A The unit is (MPa) -1 .

2. The ultrasonic shear wave detection system for stress state of thin-walled concrete structure according to claim 1, characterized in that: The first shear wave ultrasonic transducer probe and the second shear wave ultrasonic transducer probe are arranged on the slide rail tooling in a probe-to-probe transmission manner, the first shear wave ultrasonic transducer probe is fixed to the slide rail tooling, and the second shear wave ultrasonic transducer probe slides along the tooling track; The distance between the first shear wave ultrasonic transducer probe and the second shear wave ultrasonic transducer probe is measured by a length scale.

3. The ultrasonic shear wave detection system for stress state of thin-walled concrete structure according to claim 1, characterized in that: Based on the current ultrasonic propagation travel time of the first ultrasonic signal and the second ultrasonic signal, the maximum shear wave velocity v is determined. z1 ,include: a spectrum naming subunit, configured to output a first signal spectrum of the first electrical signal and a second signal spectrum of the second electrical signal when the angular rotary gear is at the first rotation angle, use the first signal spectrum as a reference spectrum, and use the second signal spectrum as a spectrum to be corrected corresponding to the reference spectrum; a signal denoising subunit, configured to denoise the signal spectrum graph corresponding to the reference spectrum graph to obtain a corresponding denoised spectrum graph; a fourth calculation subunit, configured to calculate a first peak average value and a first trough average value corresponding to the denoised spectrum graph, and simultaneously calculate a second peak average value and a second trough average value corresponding to the spectrum graph to be corrected; a fifth calculation subunit, configured to calculate a first difference between the first peak average value and the second peak average value, a second difference between the first trough average value and the second trough average value, and a third difference between the first peak average value and the first trough average value, and calculate a vertical scaling factor corresponding to the to-be-corrected spectrum graph based on a first ratio of the first difference to the third difference and a second ratio of the second difference to the third difference; a frequency determination subunit, configured to determine all zero-crossing points in the denoised spectrum to obtain a corresponding first zero-crossing point sequence, and determine a corresponding first vibration frequency based on the first zero-crossing point sequence; and simultaneously determine all zero-crossing points in the to-be-corrected spectrum to obtain a corresponding second zero-crossing point sequence, and determine a corresponding second vibration frequency based on the second zero-crossing point sequence; a sixth calculation subunit, configured to calculate a corresponding horizontal scaling factor based on the first vibration frequency and the second vibration frequency; a spectrum fitting subunit, configured to fit a corresponding fitting signal spectrum graph based on the vertical scaling factor, the horizontal scaling factor, and the denoised spectrum graph; A local correction subunit, configured to perform local correction on the to-be-corrected spectrum graph based on the fitted signal spectrum graph to obtain a corresponding corrected spectrum graph; a spectrum output subunit, configured to use the denoised spectrum corresponding to the reference spectrum as the corresponding first corrected spectrum, and use the corrected spectrum corresponding to the first corrected spectrum as the corresponding second corrected spectrum; The velocity determination subunit is configured to obtain the current ultrasonic propagation travel time based on the first wave acoustic time of the first correction spectrum and the second correction spectrum, and determine the maximum shear wave velocity v based on the current ultrasonic propagation travel time. z1 .

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