CN112305065B - SH production 0 Periodic electromagnet array electromagnetic acoustic transducer for wave guide - Google Patents
SH production 0 Periodic electromagnet array electromagnetic acoustic transducer for wave guide Download PDFInfo
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Abstract
The invention discloses a method for producing SH 0 A periodic electromagnet array electromagnetic acoustic transducer of modal guided waves belongs to the field of ultrasonic nondestructive detection. The sensor consists of a flexible circuit board, an electromagnet array, a sensor shell and a plastic gasket. The flexible circuit board is formed by connecting runway type coils integrated on the flexible circuit board in series. The electromagnet consists of an I-shaped magnetic yoke and a solenoid coil wound by enamelled wires. The electromagnets are arranged in an array with the current direction in the solenoid coils thereof being reversed staggered. SH can be realized in a plate based on the Lorentz force effect 0 Excitation of modal guided waves. The frequency of the sensor is related to the distance between the central lines of two adjacent electromagnets, and SH can be realized by changing the array arrangement interval 0 And the frequency control of the modal guided wave realizes the nondestructive testing of the plate structure.
Description
Technical Field
The invention designs a method for generating SH 0 A periodic electromagnet array electromagnetic acoustic transducer of a guided wave belongs to the technical field of ultrasonic nondestructive testing and can excite single-mode SH in a plate structure 0 The mode guided wave can be used for nondestructive testing of a metal plate type structure.
Background
The metal plate material formed by casting, forging or rolling the metal raw material is widely applied to the fields of automobile and ship manufacturing, constructional engineering and aerospace. Such as automobile engine housings, high-speed rail bodies, in-car bearings, aircraft skins, and the like, require a large number of sheet metal, particularly stainless steel and aluminum alloy sheets, for the most widespread use. However, the metal sheet inevitably has different defects such as cracks, perforation, corrosion and the like in the production, transportation, use and the like, so that the safety of the product is seriously threatened, and serious economic loss and casualties can be caused. Therefore, the nondestructive detection of the sheet metal structure is of great importance.
Disclosure of Invention
Aiming at the problems in the background technology, the invention designs the periodic electromagnet array sensor for nondestructive detection of the metal sheet defects, and the sensor designed by the invention is an electromagnetic ultrasonic transducer, and can realize the functions of non-contact, no need of couplant and the like.
The sensor is placed on the surface of a metal plate structure, and SH is directly excited in the plate by the principle of electromagnetic ultrasonic Lorentz force 0 Mode guided wave due to SH 0 The modal guided wave has the characteristic of no dispersion, so SH is utilized 0 The mode guided wave has the characteristics of wide detection range, high detection precision and the like when detecting the metal plate structure. When the metal plate has defects, the sensor can effectively detect the defects through a self-excitation self-collection or one-excitation one-collection detection mode. And then the accurate positioning of the defects can be realized by combining a related algorithm and detecting the position change.
The technical scheme of the invention is as follows: SH production 0 The periodic electromagnet array electromagnetic acoustic transducer of the modal guided wave is composed of four parts of a runway type coil (9), an electromagnet array, a sensor shell (1) and a plastic gasket (4). The runway type coil (9), the electromagnet array and the plastic gasket (4) are all arranged in the sensor shell (1);
the electromagnet array consists of a plurality of electromagnets (3) in parallel, the electromagnets (3) consist of an I-shaped magnetic yoke (5) and a close-wound coil (6), and the close-wound coil (6) is closely wound on the I-shaped magnetic yoke (5); the electromagnet array is clamped into the electromagnet clamping groove (7); the runway type coil (9) is printed on the FPC flexible circuit board (2), and the FPC flexible circuit board (2) is inserted into the FPC flexible circuit board clamping groove (8); the plastic gasket (4) is clamped in the electromagnet clamping groove (7) to control the distance between the electromagnets (3). The plate defect (11) is a structure on the metal plate (10), and the runway-shaped coil (9) is opposite to the plate defect (11).
In the scheme, the runway type coil (9) is formed by connecting n turns of each layer and m layers in series, the length of a straight line part is Lmm, the width of the straight line part is Dmm, the distance between lines is Gmm, the line width is Kmm, and the runway type coil is manufactured by adopting a printed flexible circuit board (FPC) mode.
In the scheme, the closely wound coil (6) is a copper enameled wire with the thickness of h millimeters.
In the scheme, the electromagnet (3) is formed by densely winding p turns of the densely-wound coil (6) on the I-shaped magnetic yoke (5), and the magnetic field direction of the electromagnet is the winding direction of the densely-wound coil (6), namely the horizontal direction.
In the scheme, six electromagnets (3) are sequentially arranged in parallel to form the structure shown in fig. 1, the winding directions of the adjacent electromagnets are opposite, the magnetic field directions of each electromagnet are in periodic staggered arrangement, and the length of each electromagnet is equal to the total width of a runway coil.
In the scheme, the plastic gasket (4) is a thin sheet with the thickness of xmm and made of plastic, and q sheets are used. The width is equal to the width of the electromagnet (3), and the height is slightly higher than the height of the electromagnet (3). The function is that the distance between adjacent electromagnets can be changed by adjusting the position of the plastic gasket, thereby changing the excited SH 0 The frequency of the modal guided wave.
In the scheme, the metal plate (10) is a thin aluminum plate or a thin steel plate, and the thin aluminum plate is made of a non-ferromagnetic material and has good conductivity; the thin steel plate is made of ferromagnetic material and has good magnetic permeability.
In the scheme, the plate defect (11) is prepared manually in a laboratory environment, the length of the plate defect is less than 1% of the length of the plate, and the width of the plate defect is less than 0.1% of the width of the plate.
In the above scheme, said one produces SH 0 The detection method of the periodic electromagnet array electromagnetic acoustic transducer of the modal guide wave comprises the following steps:
s1, inserting the runway-shaped coil of the printed flexible circuit board into the clamping groove (8) of the FPC along the length direction, and enabling the linear area of the runway-shaped coil to be located right below the clamping groove (7) of the electromagnet.
S2, inserting the electromagnets (3) into the electromagnet clamping grooves (7) to form the structure shown in fig. 1 after the adjacent electromagnets are wound in opposite staggered arrangement, so that the magnetic poles of the left leg and the right leg of the electromagnet array cover the linear area of the runway-shaped coil, and the central line of the electromagnet array is aligned with the central line of the runway-shaped coil.
S3, the sensor is placed on the surface of the metal plate (10) in a form of one-shot or self-excited self-shot, and the center frequency of the sensor is controlled by adjusting the position of the plastic gasket.
S4, direct current or pulse square wave current is loaded on the close winding coils of the electromagnet so that the electromagnet forms permanent magnetic fields or pulse magnetic fields with opposite adjacent magnetic fields and staggered arrangement.
S5, loading a sine signal modulated by a Hanning window into a runway coil at an excitation end, and directly loading the modulated sine signal onto the runway coil if the electromagnet is subjected to direct current loading; if the electromagnet is loaded by a pulse square wave, the high-level duration of the pulse square wave is required to be equal to the period of the Hanning window modulation sine signal, and the pulse square wave and the high-level duration of the pulse square wave are triggered simultaneously. The sensor can now generate SH in the plate by the Lorentz force mechanism 0 Modal guided waves.
S6, collecting echo signals in the self-excitation self-receiving sensor or the receiving sensor adopting a one-excitation one-receiving mode through an oscilloscope or a collecting card. At this time, if there is no defect in the sheet material, the echo signal is SH 0 End face echo signals of the modal guided waves; if the plate has a defect, the echo signal has a defect echo signal.
S7, if the echo signal has a defect echo signal, adjusting SH by adjusting the position of the plastic gasket 0 The mode guided wave frequency is used for finding out the frequency which is most sensitive to the defect, then the relevant position of the mobile sensor is used for collecting echo signals, and finally the relevant algorithm is used for realizing the accurate positioning of the defect.
Production of SH according to the present invention 0 Compared with the prior art, the periodic electromagnet array electromagnetic acoustic transducer of the modal guide wave has the following advantages:
1. the sensor designed by the invention can directly generate SH in the plate 0 Mode guided wave, SH 0 The modal guided wave has the characteristics of non-dispersion and sensitivity to defects, and can detect the defects in the metal plate. Compared with the traditional bulk wave detection method, the method has the advantages of wide detection range and less detection time consumption; compared with the traditional methodThe Lamb wave detection method has the advantages of high detection precision and purer guided wave mode.
2. The sensor designed by the invention is an electromagnetic acoustic transducer, and has the characteristics of no need of couplant and capability of non-contact detection. Compared with the traditional piezoelectric detection means, the method has the advantages of simple operation and economy and time cost saving.
3. The sensor runway coil designed by the invention is formed by connecting four layers of runway coils in series, so that the current density in the coil is improved. And the runway coil is made of a printed flexible circuit board, and is 4 layers of coils, but the thickness of the runway coil is only 0.18mm, so that the electric vortex density in the skin depth of the inner wall of the sleeve is improved. The lorentz force is enhanced by the improvement of the electric vortex density, so that the design of the coil is improved in transduction efficiency compared with the traditional single-layer coil electromagnetic ultrasonic sensor.
4. Compared with the traditional permanent magnet electromagnetic ultrasonic sensor, when the sensor detects a plate made of ferromagnetic materials, the sensor designed by the invention adopts an electromagnet as a provider of an induced magnetic field, and avoids the condition that the permanent magnet is adsorbed on the plate and cannot be taken down or scratches are generated on the plate when the permanent magnet tightly adsorbed on the plate is taken down. The magnetic force detection device has the advantages of convenience in detection, low time consumption, reduction in risk of clamping injury of detection personnel by magnets and the like.
5. Compared with the traditional permanent magnet electromagnetic ultrasonic sensor, the sensor designed by the invention adopts the electromagnet as a provider of the induction magnetic field, and compared with the traditional permanent magnet electromagnetic ultrasonic sensor, the traditional permanent magnet electromagnetic ultrasonic sensor is easy to adsorb a large amount of scrap iron, is difficult to clean and is easy to influence the detection result. The electromagnet can effectively avoid the occurrence of the situation, and simultaneously SH 0 The characteristic that the modal guided wave can not propagate in the liquid can lead the sensor not to be influenced by the liquid on the surface of the plate and the like when detecting the plate defect, and has the advantage of being suitable for detection in a field humid environment.
6. The electromagnet in the sensor designed by the invention adopts an array structure, compared with a single electromagnet for exciting SH 0 The mode guided wave is realized, and the mode excited by the sensor designed by the invention is purer. Due to the adoption of an array form, the magnetic induction intensity is highThe device has the advantages of high excitation signal energy under the double functions of larger degree and array shearing action mechanism. Meanwhile, the electromagnet in the sensor supports the excitation form of the pulse square wave, and has the advantages of reducing the heating of the electromagnet and improving the induction magnetic field.
7. The excitation frequency of the sensor designed by the invention is only related to the interval between the electromagnets, and the excitation frequency can be changed by changing the position of the plastic gasket without changing the coil, so that the sensor has the advantages of simple structure and convenience in changing the frequency.
Drawings
FIG. 1 is a simplified overall configuration of a periodic array electromagnet sensor.
Fig. 2 is a structural diagram of an i-yoke and wound into an electromagnet.
FIG. 3 is a schematic diagram of a sensor housing.
Fig. 4 is a schematic view of a racetrack coil.
FIG. 5 is a schematic view of a sheet metal and defect.
FIG. 6 is a diagram of a periodic electromagnet array sensor detection system.
FIG. 7 sheet metal SH 0 Modal guided wave propagation signal diagram.
In the figure: 1. a sensor housing; 2. an FPC flexible circuit board; 3. an electromagnet; 4. a plastic gasket; 5. an I-shaped magnetic yoke; 6. closely winding the coil; 7. an electromagnet clamping groove; 8. an FPC flexible circuit board clamping groove; 9. a racetrack coil; 10. a metal plate; 11. plate defects; 12. RPR4000; 13. receiving an impedance matching network; 14. exciting the impedance matching network; 15. an electromagnet bias magnetic field Bs; 16. exciting the sensor; 17. the coil induces eddy currents Je; 18. a function generator; 19. an oscilloscope; 20. a power amplifier; 21. SH 0 A modal guided wave propagation direction; 22. a receiving sensor; 23. lorentz force F.
Detailed Description
The invention will now be further described with reference to the accompanying drawings, by way of example only, as experiments with specific dimensions and features of the invention.
FIG. 1 is a schematic diagram showing the overall structure of a periodic array electromagnet sensor, which mainly comprises a runway coil, an electromagnet array and a sensor shellAnd the plastic gasket is composed of four parts. The flexible circuit board is formed by connecting runway type coils integrated on the flexible circuit board in series. The electromagnet consists of an I-shaped magnetic yoke and a solenoid coil wound by enamelled wires. The electromagnets are arranged in an array with the current direction in the solenoid coils thereof being reversed staggered. And placing the runway coil in the flexible circuit board on the surface of the test piece to be tested, and placing the electromagnets arranged in an array above the runway coil. SH realization in a plate based on Lorentz force effect 0 Excitation of modal guided waves. The frequency of the sensor is related to the distance between the central lines of two adjacent electromagnets, and SH can be realized by changing the array arrangement interval 0 And controlling the frequency of the modal guided wave. Experiments prove that the developed periodic electromagnet array electromagnetic acoustic transducer generates single-mode SH in the plate 0 Modal guided waves. The sensor can realize nondestructive detection of the plate structure by self-excitation self-collection or one-excitation one-collection.
In this example, the racetrack coil (9) shown in fig. 4 has 20 turns per layer, and a total of 4 layers are connected in series. The length of the straight line part is 70mm, and the width of the straight line runways on the left side and the right side is 5mm and is equal to the width of the left leg and the right leg of the electromagnet. The spacing between the lines was 0.25mm and the line width was 0.15mm.
In this example, the sheet metal shown in fig. 6 is a thin aluminum sheet with a dimension of 1000 x 10000 x 1 mm.
In this example, the electromagnet yoke material shown in fig. 6 is industrial pure iron, the winding material is a copper enameled wire with the thickness of 0.4mm, and the winding turns are 125 turns.
The electromagnets with the winding directions of adjacent electromagnets being opposite and periodically staggered are used for providing staggered pulse bias magnetic fields Bs (15) perpendicular to the aluminum plate, the runway type coil generates induced eddy currents Je (17) in the skin depth of the surface of the aluminum plate, and the induced eddy currents generate Lorentz force F (23) along the action of the pulse bias magnetic fields, so that SH with the vibration direction perpendicular to the propagation direction is excited in the aluminum plate 0 A modal guided wave (21).
The excitation sensor (16) is connected with the output end of the RPR4000 (12) after impedance matching through the excitation impedance matching network (14), and the receiving sensor (22) is connected with the input end of the RPR4000 after impedance matching through the receiving impedance matching network (13). Two monitors of the RPR4000 are connected to oscilloscopes (19) respectively to receive signals. The function generator (18) is connected to the external trigger of the RPR4000 and the input of the power amplifier (20), respectively. The output of the power amplifier is connected to the solenoid coil of the excitation and reception sensor. The function generator excites a pulse square wave with a duty cycle of 20% to control the excitation of the electromagnet to start simultaneously with the triggering of the runway coil, and the high-level duration of the square wave is equal to the period of the hanning window. Sinusoidal signals modulated by five-cycle hanning window with an excitation frequency of 155KHz by RPR4000, when the oscilloscope receives SH generated by the excitation sensor 0 The mode guided wave direct wave can receive multiple echoes, as shown in fig. 7, and is the signal received by the receiving sensor in this example.
FIG. 7 is SH in a defect-free thin aluminum plate 0 The mode guided wave receives signals, and the SH is excited in the front direction and the rear direction simultaneously due to the excitation of the excitation sensor 0 The mode guided wave, so 4 wave packets are direct wave, right wall primary echo, left wall primary echo and left to right wall secondary echo in sequence.
Claims (3)
1. SH production 0 The periodic electromagnet array electromagnetic acoustic sensor of the guided wave is characterized by comprising four parts of a runway coil, an electromagnet array, a sensor shell and a plastic gasket; the runway type coil (9), the electromagnet array and the plastic gasket (4) are all arranged in the sensor shell (1);
the electromagnet array consists of a plurality of electromagnets (3) in parallel, the electromagnets (3) consist of an I-shaped magnetic yoke (5) and a close-wound coil (6), and the close-wound coil (6) is closely wound on the I-shaped magnetic yoke (5); the electromagnet array is clamped into the electromagnet clamping groove (7); the runway type coil (9) is printed on the FPC flexible circuit board (2), and the FPC flexible circuit board (2) is inserted into the FPC flexible circuit board clamping groove (8); the plastic gasket (4) is clamped in the electromagnet clamping groove (7) to control the distance between the electromagnets (3); the plate defect (11) is a structure on the metal plate (10), and the runway coil (9) is opposite to the plate defect (11); the runway type coil (9) is formed by connecting n turns and m layers in series, the length of a straight line part is Lmm, the width of the straight line part is Dmm, the distance between lines is Gmm, the line width is Kmm,the method comprises the steps of manufacturing a printed flexible circuit board (FPC); the plastic gasket (4) is a thin sheet with the thickness of xmm made of plastic, and q sheets are all arranged; the width is equal to the width of the electromagnet (3), and the height is slightly higher than the height of the electromagnet (3); changing the distance between adjacent electromagnets by adjusting the position of the plastic shim, thereby changing the SH excited 0 The frequency of the modal guided wave.
2. A SH-producing process according to claim 1 0 The electromagnetic acoustic sensor of the periodic electromagnet array of the guided wave is characterized in that,
the width and the height of the winding area of the I-shaped magnetic yoke (5) are lower than those of the two legs, and the h millimeter enameled wire is tightly wound on the close-wound coil (6) to form a p-turn coil and then fill the winding area of the I-shaped magnetic yoke so as to form a U-shaped electromagnet; the direction of the magnetic field of the electromagnet is the winding direction of the close-wound coil (6), namely the horizontal direction; the winding directions of the adjacent electromagnets are opposite, the magnetic poles of each electromagnet are arranged in a periodic staggered manner, and the length of each electromagnet is equal to the total width of the runway coil.
3. A detection method using the periodic electromagnet array electromagnetic acoustic sensor according to any of claims 1-2, characterized by comprising the steps of,
s1, inserting a runway coil (9) manufactured into a printed flexible circuit board into an FPC flexible circuit board clamping groove (8) along the length direction, wherein a straight line area of the runway coil is positioned right below an electromagnet clamping groove (7);
s2, inserting a plurality of electromagnets (3) into the electromagnet clamping grooves (7) to form an electromagnet array after the adjacent electromagnets are wound in opposite staggered arrangement, so that the magnetic poles of the left leg and the right leg of the electromagnet array cover the linear area of the runway-shaped coil, and the central line of the electromagnet array is aligned with the central line of the runway-shaped coil;
s3, placing the sensor on the surface of the metal plate (10) in a form of one-shot or self-excited self-shot, and controlling the center frequency of the sensor by adjusting the position of the plastic gasket;
s4, direct current or pulse square wave current is loaded on the close-wound coil of the electromagnet so that the electromagnet forms permanent magnetic fields or pulse magnetic fields with opposite adjacent magnetic fields in a staggered arrangement;
s5, loading a sine signal modulated by a Hanning window into a runway coil at an excitation end, and directly loading the modulated sine signal onto the runway coil if the electromagnet is subjected to direct current loading; if the electromagnet is loaded by a pulse square wave, the high-level duration time of the pulse square wave is required to be equal to the period of a Hanning window modulation sine signal, and the pulse square wave and the Hanning window modulation sine signal are triggered simultaneously; the sensor produces SH in the plate by lorentz force mechanism 0 Mode guided wave;
s6, acquiring echo signals in the self-excitation self-receiving sensor or the receiving sensor adopting a one-excitation one-receiving mode through an oscilloscope or an acquisition card; at this time, if there is no defect in the sheet material, the echo signal is SH 0 End face echo signals of the modal guided waves; if the plate has a defect, the echo signal has a defect echo signal;
s7, if a defect echo signal exists in the echo signals, firstly adjusting the position of the plastic gasket to adjust SH 0 The mode guided wave frequency is used for finding out the frequency which is most sensitive to the defects, then the relevant position of the mobile sensor is used for collecting echo signals, and the relevant algorithm is used for realizing the accurate positioning of the plate defects (11).
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| CN117871693B (en) * | 2024-03-11 | 2024-05-17 | 西南交通大学 | Method and device for exciting zero-order horizontal shear wave in steel rail |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009068915A (en) * | 2007-09-11 | 2009-04-02 | Nippon Steel Corp | Flaw measuring instrument, flaw measuring method, program and computer-readable storage medium |
| CN202330358U (en) * | 2011-11-23 | 2012-07-11 | 北京工业大学 | SH0 electromagnetic acoustic transducer for detecting defects of plate structure |
| CN102608220A (en) * | 2012-01-09 | 2012-07-25 | 北京工业大学 | Multi-basic frequency combined SH0 model electromagnetic acoustic transducer |
| CN102662003A (en) * | 2012-04-25 | 2012-09-12 | 清华大学 | Omni-directional shear horizontal (SH) guided wave electromagnetic ultrasonic transducer |
| CN106568847A (en) * | 2016-11-14 | 2017-04-19 | 哈尔滨零声科技有限公司 | Multicoil ultrasonic guided-wave device of arbitrary frequency, and guided wave excitation method and receiving method thereof |
| CN106641734A (en) * | 2016-10-14 | 2017-05-10 | 清华大学 | Online high-temperature pipeline ultrasonic guided wave detection device based on L-shaped waveguide structure |
| CN110152963A (en) * | 2019-05-29 | 2019-08-23 | 北京工业大学 | A kind of periodic permanent magnet iron formula omni-directional horizontal shear mode Electromagnetic Acoustic Transducer |
| CN110193460A (en) * | 2019-05-29 | 2019-09-03 | 北京工业大学 | A kind of omni-directional magnetic concentrator formula Lamb wave electromagnetic sound transducer |
| CN110471010A (en) * | 2019-09-18 | 2019-11-19 | 北京工业大学 | The SH of ferrimagnet Magnetostrictive curve0Mode supersonic guide-wave measurement method |
| CN110939431A (en) * | 2019-11-26 | 2020-03-31 | 北京工业大学 | Array sensor for nondestructive detection of cement sheath defects of well cementation casing |
-
2020
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Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009068915A (en) * | 2007-09-11 | 2009-04-02 | Nippon Steel Corp | Flaw measuring instrument, flaw measuring method, program and computer-readable storage medium |
| CN202330358U (en) * | 2011-11-23 | 2012-07-11 | 北京工业大学 | SH0 electromagnetic acoustic transducer for detecting defects of plate structure |
| CN102608220A (en) * | 2012-01-09 | 2012-07-25 | 北京工业大学 | Multi-basic frequency combined SH0 model electromagnetic acoustic transducer |
| CN102662003A (en) * | 2012-04-25 | 2012-09-12 | 清华大学 | Omni-directional shear horizontal (SH) guided wave electromagnetic ultrasonic transducer |
| CN106641734A (en) * | 2016-10-14 | 2017-05-10 | 清华大学 | Online high-temperature pipeline ultrasonic guided wave detection device based on L-shaped waveguide structure |
| CN106568847A (en) * | 2016-11-14 | 2017-04-19 | 哈尔滨零声科技有限公司 | Multicoil ultrasonic guided-wave device of arbitrary frequency, and guided wave excitation method and receiving method thereof |
| CN110152963A (en) * | 2019-05-29 | 2019-08-23 | 北京工业大学 | A kind of periodic permanent magnet iron formula omni-directional horizontal shear mode Electromagnetic Acoustic Transducer |
| CN110193460A (en) * | 2019-05-29 | 2019-09-03 | 北京工业大学 | A kind of omni-directional magnetic concentrator formula Lamb wave electromagnetic sound transducer |
| CN110471010A (en) * | 2019-09-18 | 2019-11-19 | 北京工业大学 | The SH of ferrimagnet Magnetostrictive curve0Mode supersonic guide-wave measurement method |
| CN110939431A (en) * | 2019-11-26 | 2020-03-31 | 北京工业大学 | Array sensor for nondestructive detection of cement sheath defects of well cementation casing |
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