CN112147235A - Electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection - Google Patents
Electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection Download PDFInfo
- Publication number
- CN112147235A CN112147235A CN202011151891.2A CN202011151891A CN112147235A CN 112147235 A CN112147235 A CN 112147235A CN 202011151891 A CN202011151891 A CN 202011151891A CN 112147235 A CN112147235 A CN 112147235A
- Authority
- CN
- China
- Prior art keywords
- circuit board
- printed circuit
- layer
- flexible printed
- double
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005284 excitation Effects 0.000 title claims abstract description 39
- 238000001514 detection method Methods 0.000 title claims abstract description 37
- 229910001172 neodymium magnet Inorganic materials 0.000 claims abstract description 21
- 238000005516 engineering process Methods 0.000 claims abstract description 9
- 238000012360 testing method Methods 0.000 claims description 13
- 239000006185 dispersion Substances 0.000 claims description 11
- 239000000463 material Substances 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 6
- 230000008569 process Effects 0.000 claims description 5
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 claims description 3
- 239000011230 binding agent Substances 0.000 claims description 2
- 239000000945 filler Substances 0.000 claims description 2
- 239000000843 powder Substances 0.000 claims description 2
- 238000009434 installation Methods 0.000 abstract description 2
- 230000000694 effects Effects 0.000 description 5
- 239000000523 sample Substances 0.000 description 5
- 230000007547 defect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000004907 flux Effects 0.000 description 3
- 238000009659 non-destructive testing Methods 0.000 description 3
- 238000004804 winding Methods 0.000 description 3
- 229910001094 6061 aluminium alloy Inorganic materials 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000004323 axial length Effects 0.000 description 2
- 230000001934 delay Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 239000007822 coupling agent Substances 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000004807 localization Effects 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000007639 printing Methods 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 230000026683 transduction Effects 0.000 description 1
- 238000010361 transduction Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/34—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/04—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with electromagnetism
- B06B1/045—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with electromagnetism using vibrating magnet, armature or coil system
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
- G01N29/12—Analysing solids by measuring frequency or resonance of acoustic waves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B2201/00—Indexing scheme associated with B06B1/0207 for details covered by B06B1/0207 but not provided for in any of its subgroups
- B06B2201/50—Application to a particular transducer type
- B06B2201/52—Electrodynamic transducer
- B06B2201/53—Electrodynamic transducer with vibrating magnet or coil
Landscapes
- Physics & Mathematics (AREA)
- Biochemistry (AREA)
- Analytical Chemistry (AREA)
- Pathology (AREA)
- Immunology (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- General Physics & Mathematics (AREA)
- General Health & Medical Sciences (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Mechanical Engineering (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
The invention relates to an electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection, which comprises a double-layer flexible printed circuit board and a sheet rubber neodymium iron boron magnet, wherein the double-layer flexible printed circuit board is manufactured by a flexible plate making technology; the double-layer flexible printed circuit board is pasted on one surface of the sheet rubber neodymium iron boron magnet, and is positioned between the magnet and the outer surface of the tested piece during detection. The device installation is dismantled conveniently, and simple structure is compact, and the volume is less, has the flexibility, can adapt to crooked surface and narrow environment, can effectively detect and fix a position the pipeline crazing line.
Description
Technical Field
The invention belongs to the field of electromagnetic ultrasonic detection, and particularly relates to an electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection.
Background
The ultrasonic guided wave detection technology is taken as an important branch in the field of nondestructive testing, and is widely applied to the field of nondestructive testing of pipelines in recent years. The potential safety hazard caused by damage expansion can be effectively avoided by detecting and positioning the microcracks of the pipeline. However, the conventional ultrasonic nondestructive testing technology utilizes linear characteristics such as reflection and scattering of sound waves when defects are encountered in the ultrasonic wave propagation process to detect the defects, and is difficult to effectively detect the defects with the size smaller than one half of the wavelength of the detected sound waves and the defects with small acoustic impedance difference with surrounding media. In order to effectively detect the microcracks of the pipeline, a nonlinear ultrasonic detection technology can be adopted. The nonlinear ultrasonic detection technology can essentially reflect the influence of the material micro-defects on the ultrasonic wave propagation process, and can detect the micro-defects which cannot be detected by the traditional ultrasonic detection.
Since nonlinear distortion inevitably occurs in a transmission/reception system (such as an amplifier, a transducer and a coupling medium), in practice, the nonlinear higher harmonic method has a problem of false alarm or the like due to nonlinearity caused by a test system. To overcome these limitations, non-linear ultrasonic mixed-frequency detection techniques can be used, which are based on the fact that: when the two trains of waves meet in a nonlinear region containing a nonlinear source such as a closed crack, an interaction occurs, and a new frequency component is observed in the frequency domain. Therefore, the material damage can be detected, and the new frequency components can be correspondingly analyzed by controlling the wave mixing position, so that the material damage condition can be positioned.
The pipeline is subjected to nonlinear ultrasonic frequency mixing detection, an electromagnetic acoustic transducer (EMAT) can be used, the EMAT is a non-contact transducer, the detected material is not required to be contacted through a coupling agent, additional nonlinearity is inhibited, and the pipeline ultrasonic frequency mixing detection device is insensitive to common wrapping layers and oil, dirt, water, oxides and paint on the surface of a detected pipeline test piece, so that the pipeline ultrasonic frequency mixing detection device is suitable for pipeline ultrasonic detection. Two exciting transducers are needed for ultrasonic frequency mixing detection, two lines of ultrasonic waves with different frequencies are respectively excited by two multi-cluster coils at a certain distance in the conventional detection method, and the structure enables the whole transduction device to have longer axial length, larger volume and larger difference of magnetic flux densities at different positions. Currently, an EMAT generally uses a solenoid electromagnet or a rigid permanent magnet to provide a bias magnetic field, the solenoid electromagnet needs an additional power supply and is complex to install on a pipeline structure, and the permanent magnet needs to be fixed on the surface of the pipeline by using fixing devices such as an iron yoke and a hinge. Because of the large volume and the complex installation, the application of the electromagnet and the rigid permanent magnet on the pipeline electromagnetic ultrasonic transducer is limited. Therefore, when the electromagnetic ultrasonic frequency mixing detection technology is applied to the pipeline, the excitation device needs to be designed. Aiming at the requirement, the invention provides an electromagnetic ultrasonic frequency mixing excitation device suitable for a curved pipeline test piece.
Disclosure of Invention
The invention aims to design an electromagnetic ultrasonic pipeline guided wave mixing excitation device which is convenient to mount and dismount, simple and compact in structure, small in size, flexible, capable of adapting to a curved surface and a narrow environment and capable of effectively detecting and positioning microcracks of a pipeline.
In order to achieve the purpose, the invention adopts the technical scheme that:
an electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection comprises a double-layer circuit board manufactured by a flexible plate-making technology and a sheet-shaped rubber neodymium-iron-boron magnet, wherein the distances between adjacent cluster lines of a reverse-folded multi-cluster coil printed on the bottom layer and the top layer of the double-layer flexible printed circuit board are different, and the centers of the top layer coil and the bottom layer coil are at the same position; the double-layer flexible printed circuit board is pasted on one surface of the sheet rubber neodymium iron boron magnet, and is located between the magnet and the outer surface of the test piece to be detected during detection.
The flaky rubber neodymium iron boron magnet is a flexible flaky permanent magnet material which takes rubber as a binder, neodymium iron boron powder as a filler and is magnetized in the thickness direction, the polarity of the upper surface is single, and the polarity of the lower surface is single. The flexible printed circuit board is bonded with the flexible printed circuit board into a whole and can provide magnetic induction intensity along the radial direction of the pipeline when being coated on the pipeline. The width of the magnet along the axial direction is larger than that of the double-layer flexible printed circuit board, so that the coil on the circuit board is completely arranged in a magnetic field, and the top layer coil and the bottom layer coil are preferably arranged up and down to adapt to the size of the magnet with the width of the magnetizing magnet in a single direction not larger than 50 mm.
The current directions of adjacent clusters of each layer of coils of the double-layer flexible printed circuit board are opposite, excitation current signals with different frequencies are respectively introduced into the top layer of coils and the bottom layer of coils, and the distance between the adjacent clusters of each layer of coils is half of the wavelength lambda of the required modal guided wave under the corresponding excitation frequency.
The detection process of the invention is as follows:
selecting a certain modal guided wave of the current tested piece as an excitation signal according to the dispersion curve of the tested piece: the longitudinal mode guided wave has multi-mode and frequency dispersion characteristics, when the longitudinal guided wave is excited in the pipeline, L (0,1) and L (0,2) modes coexist in a low frequency band, the transducer can simultaneously excite the 2 wave modes under the same frequency, and a certain mode is determined to be a required mode according to a specific pipeline frequency dispersion curve. When the vibration excited by a certain cluster of coils is at phase velocity cpWhen the wave propagates to the distance of lambda/2, constructive interference can be generated with the homodromous point vibration caused by the adjacent cluster coils, the strength of the required mode wave guide is increased, and the other mode wave guide is inhibited.
When detection is carried out, a flexible printed circuit board is adhered to one surface of a sheet rubber neodymium iron boron magnet and is coated on a tested piece in a mode that a plurality of clusters of coils are unfolded along the circumferential direction, the flexible printed circuit board is located between the magnet and the outer surface of a pipeline, alternating currents with different frequencies are respectively introduced into the inflection coils at the top layer and the bottom layer at intervals, the alternating currents induce eddy currents in the tested piece, alternating Lorentz force is generated under a bias magnetic field provided by the rubber neodymium iron boron magnet to cause particle vibration, and the vibration can be axially transmitted along the pipeline in a longitudinal guided wave mode, so that two lines of guided waves are generated;
the current in the coil is sine pulse signal, the top coil is connected with frequency f1Excitation current of (2), bottom coil passing frequency f2C, group velocities of guided waves excited by the two layers of coils are respectively1And c2The group velocity is the velocity of envelope propagation of the wave, and the excitation current is introduced into the two-layer coil by controlling the two-layer coil according to the group velocityThe time difference can make two lines of waves reach a certain position of the pipeline simultaneously.
If the pipeline has no microcracks, the sum frequency and difference frequency nonlinear components can not appear; if the microcrack exists, the sum frequency component and the difference frequency component of two fundamental frequencies can appear, and when two columns of waves reach the microcrack position at the same time, the amplitude of the sum frequency component and the amplitude of the difference frequency component are maximum, so that the detection and the positioning of the microcrack can be completed.
Compared with the prior art, the invention has the following advantages and prominent effects:
1) two fundamental frequency signals required by ultrasonic frequency mixing nonlinear detection are respectively excited by coils on the top layer and the bottom layer, compared with a double-excitation transducer frequency mixing detection mode which is placed in parallel, the axial length is small, the miniaturization of a frequency mixing excitation device is facilitated, and the difference of magnetic flux densities of different cluster positions of the coils in an area below a magnet is small. The ultrasonic frequency mixing nonlinear detection can effectively detect microcracks and is not sensitive to system nonlinearity, and the frequency mixing technology can also scan an area by adopting different delay control positions where two trains of waves are mixed.
2) The sheet-shaped rubber neodymium-iron-boron magnet is designed aiming at the curved surface of the pipeline, has the characteristics of light weight, thinness and flexibility, can be coated on the surface of the pipeline without heavy fasteners compared with a rigid permanent magnet, and can be well attached to test pieces with various pipe diameters without surface treatment such as polishing. In addition, due to the flexible design of the magnet and the circuit board, the magnetic testing device can be well attached to any piece to be tested, the side face of the pipeline can be wrapped in the circumferential direction, and the circumferential non-closed curved face can also be wrapped.
3) The distance between adjacent clusters of the zigzag multi-cluster coil is equal to the half wavelength of the mode guided wave required under the excitation frequency, so that the vibration intensity of the mode guided wave required under the excitation frequency of each coil can be improved, other modes are inhibited, and the receiving effect of the mixed wave signal is better; the multi-cluster winding is manufactured in a flexible printed circuit board mode, is low in cost compared with a winding wire, is convenient for accurately controlling the interval between adjacent clusters of the winding, does not need to be wound during use, is directly attached to the surface of a pipeline along with the rubber permanent magnet, and is convenient to install and disassemble.
4) The total thickness of the adopted double-layer flexible printed circuit board is 0.13mm +/-0.03mm, which is thinner than that of a common double-layer PCB, the coil lifting distance is short, the excitation effect is better, and the distance between the bottom layer and the top layer is small, so that the excitation effect of the coil positioned on each layer is similar.
Drawings
FIG. 1 is a schematic structural diagram of an electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection according to the present invention installed on a pipeline;
FIG. 2 is a schematic diagram of the excitation process of the electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection according to the present invention;
FIG. 3 is a schematic view showing an opened state of a double-layered flexible printed circuit board according to the present invention;
FIG. 4 is a phase velocity and group velocity dispersion curve of longitudinal mode guided waves of an aluminum alloy pipeline with an outer diameter of 45mm and a wall thickness of 1 mm;
FIG. 5 shows the received signals at excitation frequencies of 900kHz and 1300 kHz;
FIG. 6 is a frequency domain plot of a received signal;
FIG. 7 is a schematic view of the apparatus of the present invention applied to a non-closed curved surface to be tested;
in the figure, 1 is a magnet, 2 is a double-layer flexible printed circuit board, and 3 is a test piece.
Detailed Description
The present invention is further explained with reference to the following examples and drawings, but the scope of the present invention is not limited thereto.
As shown in fig. 1, the electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection of the present invention is applied to pipeline guided wave frequency mixing detection, and is composed of a sheet-shaped rubber neodymium iron boron magnet 1, and a double-layer flexible printed circuit board 2 with coils printed on the top layer and the bottom layer respectively; when detecting, paste double-deck flexible printed circuit board in the one side of slice rubber neodymium iron boron magnetism body, with this whole cladding in 3 surfaces of pipeline test pieces under test for double-deck flexible printed circuit board's many cluster coils expand along circumference, and the width of the axial width in edge of magnet is greater than double-deck flexible printed circuit board's width, makes the coil on the double-deck flexible printed circuit board arrange in the magnetic field completely. The coil adopts the many bunches of coil forms of the type of the inflection, the central point that is located the inflection coil of top and bottom is the same, the coaxial line when two-layer coil open state, the whole width of two-layer coil can be different, but the axial line is aligned when printing on the circuit board from top to bottom, namely the central point is the same. Alternating currents with different frequencies are respectively introduced into the top coil and the bottom coil, and two lines of longitudinal guided waves are excited by using the double-output channels and the output delay function of the excitation source. Two lines of waves can reach a certain position of a pipeline at the same time by controlling the time difference of exciting currents introduced into the two layers of coils, the position where the two lines of waves are mixed is controlled by adopting a series of time delays, and the sum frequency component amplitude and the difference frequency component amplitude are observed, so that the region is scanned.
Fig. 2 is a schematic diagram showing the excitation principle of the electromagnetic ultrasonic excitation device for guided wave mixing detection of a pipeline according to the present invention. High-frequency high-power exciting current J is respectively led into coils printed on the bottom layer and the top layer of the double-layer circuit boardm1And Jm2Wherein Jm1The frequency is higher. As shown in FIG. 2 (a), the current J is first excitedm1Inducing a vortex J in the skin depth of the tubinge1The eddy current is acted by Lorentz force under the action of magnetic field to induce the high-frequency vibration of surface particles to generate a longitudinal guided wave. As shown in FIG. 2 (b), the excitation current J is delayed by a certain timem2Inducing a vortex Je2And obtaining a second row of longitudinal guided waves in the same way, wherein the second row of longitudinal guided waves meet the first row of longitudinal guided waves at a certain position and are controlled to be introduced into two groups of coils to excite current Jm1And Jm2The time difference of (a) controls the position of the wave mixing.
The double-layer flexible printed circuit board structure is shown in fig. 3, wherein the whole double-layer flexible printed circuit board is 4, the zigzag coils printed on the bottom layer, namely bottom layer coils, are 5, the zigzag coils printed on the top layer, namely top layer coils, are 6, the distance between adjacent clusters of each layer of coils is half of the required modal guided wave wavelength lambda under the corresponding excitation frequency, namely cp/2f, wherein cpIs the phase velocity of the guided wave, f is the guided waveOf (c) is detected. The adjacent cluster spacing of the top and bottom loops is unequal.
As shown in fig. 7, the test piece is a semicircular pipe wall test piece, such as 2 is a double-layer flexible printed circuit board, and 3 is a test piece.
Example (b):
the microcracks of 6061 aluminum alloy pipes with the outer diameter of 45mm and the wall thickness of 1mm are detected as an example.
FIG. 4 is a phase velocity and group velocity dispersion curve of longitudinal mode guided waves of a 6061 aluminum alloy pipeline with the outer diameter of 45mm and the wall thickness of 1 mm. According to the frequency dispersion curve of the pipeline, the L (0,2) mode guided wave has the characteristic of almost non-frequency dispersion at lower frequency, so that the signal is easier to explain, the propagation speed is high, and the L (0,2) mode guided wave is easy to distinguish from other modes, so that the L (0,2) mode guided wave is adopted as an excitation signal. According to the dispersion curve, the phase velocity of the L (0,2) mode guided wave of 0.9MHz is 5288m/s, so its wavelength λ15.876mm, 2.938mm half wavelength, 1.3MHz L (0,2) mode guided wave phase velocity of 5192m/s, wavelength lambda23.994mm and a half wavelength of 1.997 mm. The distance between adjacent cluster lines of the top-layer coil of the double-layer flexible printed circuit board is 2.938mm, the distance between adjacent cluster lines of the bottom-layer coil is 1.997mm, the two adjacent cluster lines are 12 cluster coils, the length of a single cluster of the coil is 125mm, the single cluster is close to the diameter of the pipe, and the coil can be considered to be wound around the pipe for a circle after the connection details of the end part are ignored. For stronger excitation effect, the top coil is connected with an excitation signal of 0.9MHz, and the bottom coil is connected with an excitation signal of 1.3 MHz.
The double-layer flexible printed circuit board uses 0.5OZ copper clad, the total thickness of the laminate is 0.13mm +/-0.03mm, and the distance between the top layer and the bottom layer is about 0.074 mm. The thickness of the sheet rubber neodymium iron boron magnet is 5mm, the width of the sheet rubber neodymium iron boron magnet is 50mm, the length of the sheet rubber neodymium iron boron magnet is 140mm, the lower surface of the sheet rubber neodymium iron boron magnet is an N pole, and the residual magnetic flux density is 800 mT.
When in detection, the central position of a printed coil on the double-layer flexible printed circuit board is set to be 0, and the position of the ultrasonic receiving probe is set to be 300 mm. There is a micro-crack somewhere between the excitation device and the receiving probe. According to a group velocity dispersion curve, the group velocity of the L (0,2) mode guided wave of 1.3MHz is 4799m/s, the group velocity of the L (0,2) mode guided wave of 0.9MHz is 5139m/s, so that the excitation signal of the bottom coil does not have time delay, the excitation signal time delay of the top coil is t, the time delay when the two trains of waves meet at the position of the receiving probe is the maximum time delay, according to calculation, the maximum time delay is 4.1 microseconds, in order to realize damage positioning, different time delays from 0 to 4.1 microseconds are adopted to scan the region, and the smaller the scanning time step length is, the higher the positioning precision is. In the experiment, scanning is carried out in a time step of 0.455 microsecond, the scanning frequency is 10, the error is +/-16.7 mm, and in the experiment, the scanning of the 5 th time, namely when the delay time t is 2.275 microseconds, the sum of the sum frequency component amplitude and the difference frequency component amplitude is the largest. The microcrack position is calculated to be 167mm +/-16.7 mm. The actual measured crack was at 163mm, within design tolerances. Fig. 5 shows the received signal when the delay time t is 2.275 μ s, which includes the propagation time of the wave in the ultrasonic receiving probe (the ultrasonic receiving probe does not belong to the excitation device of the present application, and belongs to the external device). Fig. 6 is a frequency domain diagram of the received signal after fourier transform, where 7 and 8 are fundamental frequency components of 0.9MHz and 1.3MHz, 9 is a difference frequency component of two fundamental frequencies, and 10 is a sum frequency component of two fundamental frequencies. The above examples demonstrate that the present invention can accomplish the detection and localization of microcracks.
Nothing in this specification is said to apply to the prior art.
Claims (7)
1. An electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection is characterized by comprising a double-layer flexible printed circuit board and a sheet rubber neodymium iron boron magnet, wherein the double-layer flexible printed circuit board is manufactured by a flexible plate making technology; the double-layer flexible printed circuit board is pasted on one surface of the sheet rubber neodymium iron boron magnet, and is positioned between the magnet and the outer surface of the tested piece during detection.
2. The device of claim 1, wherein the sheet rubber neodymium iron boron magnet is a flexible sheet permanent magnet material which takes rubber as a binder, takes neodymium iron boron powder as a filler and is magnetized in the thickness direction.
3. The apparatus of claim 1, wherein the magnet has a width in the axial direction that is greater than a width of the double-layer flexible printed circuit board such that the coil on the double-layer flexible printed circuit board is completely exposed to the magnetic field.
4. The device of claim 1, wherein the directions of currents flowing between adjacent clusters of each layer of coils of the double-layer flexible printed circuit board are opposite, excitation current signals with different frequencies are respectively introduced into the top layer of coils and the bottom layer of coils, and the distance between the adjacent clusters of each layer of coils is half of the wavelength λ of the required modal guided wave at the corresponding excitation frequency.
5. The apparatus of claim 1, wherein the double-layer flexible printed circuit board has a total thickness of 0.13mm +/-0.03 mm; the distance between the top layer coil and the bottom layer coil is 0.074 mm.
6. The apparatus of claim 1, wherein the detection process is: acquiring the frequency dispersion characteristic of a tested piece, determining that a certain longitudinal mode of the tested piece to be detected is a required mode, and selecting certain mode guided wave of the current tested piece as an excitation signal according to the frequency dispersion curve of the tested piece;
when detection is carried out, a double-layer flexible printed circuit board is adhered to one surface of a sheet rubber neodymium iron boron magnet, and is coated on a tested piece in a mode that a plurality of clusters of coils are unfolded along the circumferential direction, the flexible printed circuit board is positioned between the magnet and the outer surface of the tested piece, alternating currents with different frequencies are respectively introduced into the folding coils at the top layer and the bottom layer at intervals, the alternating currents induce eddy currents in the tested piece, alternating Lorentz force is generated under a bias magnetic field provided by the rubber neodymium iron boron magnet to cause mass point vibration, and the vibration can be axially transmitted along a pipeline in a longitudinal guided wave mode, so that two rows of guided waves are generated;
the current in the coil is sine pulse signal, the top coil is connected with frequency f1Excitation current of (2), bottom coil passing frequency f2The group velocity of the guided wave excited by the two layers of coilsIs c1And c2Setting the time difference of exciting currents introduced into the two layers of coils according to the group velocity, and enabling the two lines of waves to reach a certain position of the pipeline simultaneously under the time difference;
if the pipeline has no microcracks, the sum frequency and difference frequency nonlinear components can not appear; if the microcrack exists, the sum frequency component and the difference frequency component of two fundamental frequencies can appear, when two columns of waves reach the microcrack position at the same time, the amplitude of the sum frequency component and the amplitude of the difference frequency component are maximum, and therefore the microcrack can be detected and positioned.
7. The apparatus of claim 1, wherein the test piece is a pipe, a non-closed curved surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011151891.2A CN112147235A (en) | 2020-10-23 | 2020-10-23 | Electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011151891.2A CN112147235A (en) | 2020-10-23 | 2020-10-23 | Electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112147235A true CN112147235A (en) | 2020-12-29 |
Family
ID=73954907
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011151891.2A Pending CN112147235A (en) | 2020-10-23 | 2020-10-23 | Electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112147235A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113466347A (en) * | 2021-06-16 | 2021-10-01 | 西安交通大学 | Semi-flexible electromagnetic ultrasonic probe for detecting defects of pipeline type components |
| CN114113337A (en) * | 2021-12-07 | 2022-03-01 | 西安交通大学 | Electromagnetic ultrasonic flexible array probe for detecting defects of curved surface structure and detection method |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB0109440D0 (en) * | 1999-02-02 | 2001-06-06 | Csi Technology Inc | Enhanced detection of vibration |
| KR100430385B1 (en) * | 2003-06-04 | 2004-05-10 | (주) 이우티이씨 | A magnetic locator for locating buried objects by using magnetic markers |
| US20090078049A1 (en) * | 2007-09-25 | 2009-03-26 | The Regents Of The University Of California | Non-contact feature detection using ultrasonic lamb waves |
| US7560920B1 (en) * | 2005-10-28 | 2009-07-14 | Innovative Materials Testing Technologies, Inc. | Apparatus and method for eddy-current scanning of a surface to detect cracks and other defects |
| US8013600B1 (en) * | 2007-11-19 | 2011-09-06 | Sandia Corporation | Mountable eddy current sensor for in-situ remote detection of surface and sub-surface fatigue cracks |
| DE102011016083A1 (en) * | 2011-04-05 | 2012-10-11 | Sciknowtec Gmbh | Method for transmitting modulated radio frequency (RF) signals from transmitting station through RF-proof wall to receiving station, involves transforming data signals into waveform to overcome wall by overlay/Heterodyn transponder |
| CN104198594A (en) * | 2014-06-11 | 2014-12-10 | 北京工业大学 | Multiple-main-frequency combined torsional-mode electromagnetic acoustic array sensor |
| CN109765562A (en) * | 2018-12-10 | 2019-05-17 | 中国科学院声学研究所 | A kind of three-dimensional looking forward sound sonar system and method |
| 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 |
| CN111157628A (en) * | 2020-01-22 | 2020-05-15 | 河北工业大学 | Electromagnetic ultrasonic excitation device for depth stress detection |
| CN213302105U (en) * | 2020-10-23 | 2021-05-28 | 河北工业大学 | Electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection |
-
2020
- 2020-10-23 CN CN202011151891.2A patent/CN112147235A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB0109440D0 (en) * | 1999-02-02 | 2001-06-06 | Csi Technology Inc | Enhanced detection of vibration |
| KR100430385B1 (en) * | 2003-06-04 | 2004-05-10 | (주) 이우티이씨 | A magnetic locator for locating buried objects by using magnetic markers |
| US7560920B1 (en) * | 2005-10-28 | 2009-07-14 | Innovative Materials Testing Technologies, Inc. | Apparatus and method for eddy-current scanning of a surface to detect cracks and other defects |
| US20090078049A1 (en) * | 2007-09-25 | 2009-03-26 | The Regents Of The University Of California | Non-contact feature detection using ultrasonic lamb waves |
| US8013600B1 (en) * | 2007-11-19 | 2011-09-06 | Sandia Corporation | Mountable eddy current sensor for in-situ remote detection of surface and sub-surface fatigue cracks |
| DE102011016083A1 (en) * | 2011-04-05 | 2012-10-11 | Sciknowtec Gmbh | Method for transmitting modulated radio frequency (RF) signals from transmitting station through RF-proof wall to receiving station, involves transforming data signals into waveform to overcome wall by overlay/Heterodyn transponder |
| CN104198594A (en) * | 2014-06-11 | 2014-12-10 | 北京工业大学 | Multiple-main-frequency combined torsional-mode electromagnetic acoustic array sensor |
| CN109765562A (en) * | 2018-12-10 | 2019-05-17 | 中国科学院声学研究所 | A kind of three-dimensional looking forward sound sonar system and method |
| 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 |
| CN111157628A (en) * | 2020-01-22 | 2020-05-15 | 河北工业大学 | Electromagnetic ultrasonic excitation device for depth stress detection |
| CN213302105U (en) * | 2020-10-23 | 2021-05-28 | 河北工业大学 | Electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection |
Non-Patent Citations (1)
| Title |
|---|
| 郝煜朝: "基于电磁超声导波的管道微裂纹检测", 《硕士电子期刊》, 16 January 2023 (2023-01-16), pages 3 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113466347A (en) * | 2021-06-16 | 2021-10-01 | 西安交通大学 | Semi-flexible electromagnetic ultrasonic probe for detecting defects of pipeline type components |
| CN114113337A (en) * | 2021-12-07 | 2022-03-01 | 西安交通大学 | Electromagnetic ultrasonic flexible array probe for detecting defects of curved surface structure and detection method |
| CN114113337B (en) * | 2021-12-07 | 2024-02-20 | 西安交通大学 | Electromagnetic ultrasonic flexible array probe for detecting defects of curved surface structure and detection method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Hirao et al. | An SH-wave EMAT technique for gas pipeline inspection | |
| US6424150B2 (en) | Magnetostrictive sensor rail inspection system | |
| CN108508085A (en) | A kind of torsion mode magneto strictive sensor, pipe detection system and method | |
| US4127035A (en) | Electromagnetic transducer | |
| KR100476848B1 (en) | Method and apparatus for long range inspection of plate-type ferromagnetic structures | |
| US6624628B1 (en) | Method and apparatus generating and detecting torsional waves for long range inspection of pipes and tubes | |
| US3555887A (en) | Apparatus for electroacoustically inspecting tubular members for anomalies using the magnetostrictive effect and for measuring wall thickness | |
| CN108562642B (en) | Electromagnetic transduction device of longitudinal mode ultrasonic guided wave, pipeline detection system and method | |
| CN107790363B (en) | Array type multi-angle spiral SH guided wave electromagnetic ultrasonic transducer | |
| KR101052800B1 (en) | Method for wall thinning monitoring of a pipe using magnetostrictive transducers and the variation of the dispersion characteristics of the broadband multimode SH waves | |
| CN202330358U (en) | SH0 electromagnetic acoustic transducer for detecting defects of plate structure | |
| RU2413214C2 (en) | Apparatus for nondestructive inspection of ferromagnetic structural elements | |
| CN109444270B (en) | Electromagnetic ultrasonic and pulse eddy current composite detection sensor | |
| CN108956762A (en) | The effective flexible electromagnetic ultrasonic guide wave sensor of one kind and detection method | |
| JPH11502020A (en) | Non-destructive evaluation of pipes and tubes using magnetostrictive sensors | |
| EP0741866A1 (en) | Gas pipeline wall thickness and flaw detection | |
| WO1996013720A9 (en) | Gas pipeline wall thickness and flaw detection | |
| CN213302105U (en) | Electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection | |
| Liu et al. | Adhesive debonding inspection with a small EMAT in resonant mode | |
| CN112147235A (en) | Electromagnetic ultrasonic excitation device for pipeline guided wave frequency mixing detection | |
| CN110603442A (en) | Electromagnetic acoustic transducer (EMAT) for corrosion mapping | |
| Fang et al. | Axial magnetized patch for efficient transduction of longitudinal guided wave and defect identification in concrete‐covered pipe risers | |
| CN107991393A (en) | A kind of double frequency electromagnetic acoustic detecting system | |
| Sawaragi et al. | Improvement of SH-wave EMAT phased array inspection by new eight segment probes | |
| CN113155977A (en) | Electromagnetic ultrasonic surface wave transducer for high-temperature metal detection and detection method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |