CN113916165A - Lamb wave thickness resonance method for measuring thickness of each layer of double-layer plate - Google Patents
Lamb wave thickness resonance method for measuring thickness of each layer of double-layer plate Download PDFInfo
- Publication number
- CN113916165A CN113916165A CN202111146356.2A CN202111146356A CN113916165A CN 113916165 A CN113916165 A CN 113916165A CN 202111146356 A CN202111146356 A CN 202111146356A CN 113916165 A CN113916165 A CN 113916165A
- Authority
- CN
- China
- Prior art keywords
- thickness
- layer
- double
- layer plate
- lamb wave
- 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
- 235000019687 Lamb Nutrition 0.000 title claims abstract description 43
- 238000009774 resonance method Methods 0.000 title claims abstract description 18
- 239000000523 sample Substances 0.000 claims description 26
- 238000001514 detection method Methods 0.000 claims description 9
- 230000005284 excitation Effects 0.000 claims description 7
- 238000002474 experimental method Methods 0.000 claims description 7
- 238000004590 computer program Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 6
- 238000001228 spectrum Methods 0.000 claims description 6
- 230000008859 change Effects 0.000 claims description 4
- 239000007822 coupling agent Substances 0.000 claims description 3
- 238000005259 measurement Methods 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 5
- 238000000691 measurement method Methods 0.000 abstract description 2
- 230000007547 defect Effects 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 71
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 9
- 229910052782 aluminium Inorganic materials 0.000 description 9
- 239000005028 tinplate Substances 0.000 description 8
- 230000008901 benefit Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 238000002592 echocardiography Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 238000013441 quality evaluation Methods 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B17/00—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
- G01B17/02—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations for measuring thickness
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
Abstract
The invention discloses a Lamb wave thickness resonance method for measuring the thickness of each layer of a double-layer plate. The method utilizes multi-mode thickness resonance generated by ultrasonic Lamb waves at a cut-off frequency to represent the thickness of each layer of the double-layer plate; the method overcomes the defect that echo signals are mutually mixed and cannot be measured when the plate thickness is less than twice of the wavelength by the traditional ultrasonic pulse echo thickness measurement method, and can well measure the thickness of each layer when the thickness of the double-layer plate is in the wavelength order or even less than the wavelength.
Description
Technical Field
The invention relates to the field of ultrasound, in particular to a Lamb wave thickness resonance method for measuring the thickness of each layer of a double-layer plate.
Background
The plate-shaped solid material has very wide application in the aspects of building industry, aerospace, pressure vessel manufacturing, medicine, coating technology and the like. Compared with a single-layer plate made of a single material and with a single thickness, the double-layer plate structure can exert the advantages of each material on the premise of not reducing the performance of the product, realize the optimal configuration of material resources, present the effects of high rigidity, good impact performance, low cost and the like, and has good economic and social benefits. In a series of performance indexes for representing the quality of the laminate, the thickness is not only a parameter for representing the geometric dimension of the laminate, but also has great influence on the performance and the service life of the laminate, so that the thickness becomes one of the important parameters in the quality evaluation of the laminate.
The ultrasonic measurement method has the advantages of long propagation distance, strong penetrating power, low requirement on a tested structure, small influence on a tested environment and the like. At present, the method for measuring the thickness of each layer of a double-layer plate is a pulse-echo method, which is mainly based on the principle of measuring the propagation time of an ultrasonic pulse in a sample and then determining the thickness of the sample according to the propagation speed, as described in document 1(DEM C ˇ ENKO A, AKKER MANR, VISER H A. ultrasonic measurements of unidimensioned controlled layer thickness in a determined controlled structure [ J ]. Ndt & E International,2016(77): 63-72). The ultrasonic transducer generates a pulse wave with a certain frequency, and the pulse wave is vertically incident to the surface of the sample. When an incident wave propagates in different media, a reflected wave is generated at the interface between two adjacent media. However, when the thickness of the thin layer is less than twice the wavelength, the reflected echoes at the upper surface, the lower surface and the interface of the sample to be measured are mixed together and are not easy to distinguish, so that the thickness measurement of the thin layer cannot be realized.
Disclosure of Invention
The invention aims to provide a Lamb wave thickness resonance method for measuring the thickness of each layer of a double-layer plate.
The technical solution for realizing the purpose of the invention is as follows: a Lamb wave thickness resonance method for measuring the thickness of each layer of a double-layer plate is characterized in that a change curve of a Lamb wave cut-off frequency of the double-layer plate and the thickness ratio of the double-layer plate is determined, the cut-off frequency is measured through experiments, the corresponding thickness ratio is found, and the thickness of each layer is calculated.
Further, the relationship between the Lamb wave cut-off frequency of the double-layer plate and the thickness of the plate is derived by theory, wherein the thickness of each layer is described by the thickness ratio and the total thickness of the double-layer plate.
And (3) carrying out excitation detection experiment of Lamb wave thickness resonance mode by using an ultrasonic longitudinal wave straight probe to obtain the cut-off frequency of the sample to be detected, and then finding out the corresponding thickness ratio by contrasting a curve of the theoretical cut-off frequency changing along with the thickness ratio of the double-layer plate.
Let the density of the two plates be ρiLongitudinal waveVelocity cLiTransverse wave velocity of cTiThe thickness ratio is r, i represents the number of the layers, i is 1 and 2, the total thickness of the double-layer plate is d, and the Lamb wave cut-off frequency f of the double-layer plate is obtainedcThe relationship with the thickness ratio r is:
or
Further, under the condition that the material density, the transverse wave speed and the total thickness of the double-layer plate are known, corresponding Lamb wave cut-off frequencies under different thickness ratios r are obtained, and a curve of the Lamb wave cut-off frequency of the double-layer plate changing along with the thickness ratio r is drawn.
Further, an ultrasonic straight probe is used for exciting the thin double-layer plate, the probe is perpendicular to the surface of the sample through a coupling agent for excitation, and the ultrasonic probe is also used as a detection device and is connected with an oscilloscope through an ultrasonic signal generator; detecting to obtain a time domain signal, obtaining a frequency spectrum after Fourier transform, finding a corresponding thickness ratio r by using a formant frequency value obtained from the frequency spectrum and contrasting a curve of Lamb wave cut-off frequency changing along with the thickness ratio r, and then calculating the thickness h of the first layer of the double-layer plate1Comprises the following steps:
thickness h of the second layer2Comprises the following steps:
wherein d is the total thickness of the double-layer plate.
A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the Lamb wave thickness resonance method for measuring the thickness of each layer of a two-layer plate when executing the computer program.
A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the above-mentioned steps of the Lamb wave thickness resonance method of measuring the thickness of each layer of a two-layer plate.
Compared with the prior art, the invention has the beneficial effects that: lamb wave is a plate wave, and when the thickness of the double-layer plate is in the wavelength order or even smaller than the wavelength, the thickness of each layer can be determined by detecting the Lamb wave cut-off frequency of the double-layer plate.
The present invention is described in further detail below with reference to the attached drawing figures.
Drawings
FIG. 1 is a schematic representation of the geometry of a double plate of aluminum/tin plate.
FIG. 2 shows a Lamb wave A of a double-layer plate of aluminum plate/tin plate when the thickness ratio r is varied1Graph of the change in modal cut-off frequency.
FIG. 3 is a schematic diagram of an experimental apparatus for carrying out the method.
Detailed Description
The invention provides a Lamb wave thickness resonance method for measuring the thickness of each layer of a double-layer plate, wherein the Lamb wave cut-off frequency of the double-layer plate is related to the thickness ratio of the double-layer plate. And carrying out excitation detection experiment of a Lamb wave thickness resonance mode by using an ultrasonic longitudinal wave straight probe to obtain the cut-off frequency of the sample, and finding out the corresponding thickness ratio by referring to a curve of the theoretical cut-off frequency along with the change of the thickness ratio of the double-layer plate so as to obtain the thickness of each layer.
The specific implementation mode is as follows:
firstly, obtaining Lamb wave cut-off frequencies corresponding to different thickness ratios r through the following formula under the condition that the material density, the transverse wave speed and the total thickness of the double-layer plate are known;
or
Wherein the density of the two plates is rhoiLongitudinal wave velocity of cLiTransverse wave velocity of cTiThe thickness ratio is r, i represents the number of layers, i is 1 or 2, and the total thickness of the double-layer plate is d.
Secondly, making a curve of the Lamb wave cut-off frequency of the double-layer plate changing along with the thickness ratio r of the double-layer plate;
thirdly, carrying out excitation detection experiment of Lamb wave thickness resonance mode by using an ultrasonic longitudinal wave straight probe to obtain cut-off frequency of the sample;
the thin double-layer plate is excited by an ultrasonic straight probe, the probe is perpendicular to the surface of the sample to be excited through a coupling agent, and the ultrasonic probe is also used as a detection device and is connected with an oscilloscope through an ultrasonic signal generator. And detecting to obtain a time domain signal, performing Fourier transform to obtain a frequency spectrum, and finding a formant frequency value in the frequency spectrum.
And fourthly, finding out the corresponding thickness ratio r in the curve of the second step by using the cut-off frequency measured in the third step, and then calculating the thickness of each layer of the double-layer plate. First layer thickness h of double-layer plate1Comprises the following steps:
thickness h of the second layer2Comprises the following steps:
where d represents the total thickness of the double-layer plate.
The present invention will be described in detail below with reference to the accompanying drawings and examples.
Examples
The Lamb wave thickness resonance method for measuring the thickness of each layer of the double-layer plate takes an aluminum plate/tin plate double-layer plate as an example, the total thickness of the two plates is 1mm, the density and the transverse wave speed of the aluminum plate and the tin plate are known, the thickness of the two plates is to be measured, and fig. 1 is a schematic diagram of the double-layer plate.
Firstly, simulating to obtain corresponding thickness ratios r under different thickness ratios r through a formula of Lamb wave cut-off frequency and double-layer plate thickness ratio rAluminum plate/tin plate double-layer plate Lamb wave A1The modal cut-off frequency, wherein r is the ratio of the thickness of the aluminum plate to the thickness of the tin plate, and the variation range of r is 1/9-9;
secondly, making a Lamb wave A of a double-layer plate of an aluminum plate/a tin plate1The modal cut-off frequency is plotted as a function of the thickness ratio r of the bilayer, see FIG. 2, from which it can be seen that the bilayer A1The modal cut-off frequency is monotonically increased along with the thickness ratio r of the two plates, and the two are in one-to-one correspondence;
thirdly, an ultrasonic longitudinal wave straight probe is used for carrying out excitation detection experiment of Lamb wave thickness resonance mode, and fig. 3 is an experimental device diagram. Obtaining a double-layer plate sample A to be detected by detection1Modal cut-off frequency, where the thickness of the aluminum and tin plates in the double plate is unknown;
fourthly, because of the double-layer plate A of the aluminum plate/the tin plate1The modal cut-off frequency corresponds to the thickness ratio r of the double-layer plate one by one, so that the cut-off frequency measured in the step three can find the unique thickness ratio r in the curve of the step two, the total thickness of the double-layer plate is 1mm, the thickness of each layer and the thickness h of the tin layer can be calculated1Comprises the following steps:
thickness h of the aluminum layer2Comprises the following steps:
it should be noted that, for those skilled in the art, various modifications and equivalents can be made without departing from the principle of the present invention, and those modifications and equivalents of the claims are intended to fall within the scope of the present invention.
Claims (8)
1. A Lamb wave thickness resonance method for measuring the thickness of each layer of a double-layer plate is characterized in that: determining a change curve of the double-layer plate Lamb wave cut-off frequency and the double-layer plate thickness ratio, measuring the cut-off frequency through experiments, finding out the corresponding thickness ratio, and calculating the thickness of each layer.
2. The Lamb wave thickness resonance method for measuring the thickness of each layer of a double-layer plate as claimed in claim 1, wherein the Lamb wave cut-off frequency f of the double-layer plate iscThe relationship with the thickness ratio r is:
or
Where ρ isiIs the density of two plates, cLiIs the velocity of longitudinal wave, cTiThe transverse wave velocity is represented by r, i represents the thickness ratio, i is 1 or 2, and d represents the total thickness of the double-layer plate.
3. The Lamb wave thickness resonance method for measuring the thickness of each layer of the double-layer plate as claimed in claim 2, wherein the Lamb wave cut-off frequency is obtained under different thickness ratios r under the condition that the material density, the transverse wave velocity and the total thickness of the double-layer plate are known, and a curve of the Lamb wave cut-off frequency of the double-layer plate along with the thickness ratio r is obtained.
4. The Lamb wave thickness resonance method of claim 3, wherein the thickness of each layer is described by the thickness ratio and the total thickness of the double-layer plate.
5. The Lamb wave thickness resonance method for measuring the thickness of each layer of a double-layer plate as claimed in claim 3, wherein an ultrasonic longitudinal wave straight probe is used for carrying out excitation detection experiment of a Lamb wave thickness resonance mode to obtain the cut-off frequency of a sample to be measured, and then the corresponding thickness ratio can be found by referring to a curve that the cut-off frequency changes along with the thickness ratio of the double-layer plate.
6. Measurement according to claim 5The Lamb wave thickness resonance method for the thicknesses of all layers of the double-layer plate is characterized in that an ultrasonic straight probe is used for exciting the thin double-layer plate, the probe is perpendicular to the surface of a sample through a coupling agent for excitation, and the ultrasonic probe is used as a detection device and is connected with an oscilloscope through an ultrasonic signal generator; detecting to obtain a time domain signal, obtaining a frequency spectrum after Fourier transform, finding a corresponding thickness ratio r by using a formant frequency value obtained from the frequency spectrum and contrasting a curve of Lamb wave cut-off frequency changing along with the thickness ratio r, and calculating the thickness h of the first layer of the double-layer plate1Comprises the following steps:
thickness h of the second layer2Comprises the following steps:
7. a computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the steps of the Lamb wave thickness resonance method for measuring the thickness of each layer of a two-layer plate according to any one of claims 1 to 6 when executing the computer program.
8. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the Lamb wave thickness resonance method of measuring the thickness of each layer of a two-layer plate according to any one of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111146356.2A CN113916165A (en) | 2021-09-28 | 2021-09-28 | Lamb wave thickness resonance method for measuring thickness of each layer of double-layer plate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111146356.2A CN113916165A (en) | 2021-09-28 | 2021-09-28 | Lamb wave thickness resonance method for measuring thickness of each layer of double-layer plate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113916165A true CN113916165A (en) | 2022-01-11 |
Family
ID=79236995
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111146356.2A Pending CN113916165A (en) | 2021-09-28 | 2021-09-28 | Lamb wave thickness resonance method for measuring thickness of each layer of double-layer plate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113916165A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114923442A (en) * | 2022-05-18 | 2022-08-19 | 南京理工大学 | Method and device for measuring thickness of each layer of double-layer thin plate based on ultrasonic Lamb wave zero group velocity resonance |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105910559A (en) * | 2016-06-13 | 2016-08-31 | 南京航空航天大学 | Method for utilizing Lamb waves to detect thicknesses of frozen ice layers of rotor wing |
| CN108286952A (en) * | 2017-12-13 | 2018-07-17 | 大连理工大学 | A kind of coating layer thickness, density and longitudinal wave velocity ultrasonic inversion method simultaneously |
| CN110672047A (en) * | 2019-10-16 | 2020-01-10 | 江苏省特种设备安全监督检验研究院 | Laser ultrasonic measurement method for thickness of high-temperature metal material |
-
2021
- 2021-09-28 CN CN202111146356.2A patent/CN113916165A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105910559A (en) * | 2016-06-13 | 2016-08-31 | 南京航空航天大学 | Method for utilizing Lamb waves to detect thicknesses of frozen ice layers of rotor wing |
| CN108286952A (en) * | 2017-12-13 | 2018-07-17 | 大连理工大学 | A kind of coating layer thickness, density and longitudinal wave velocity ultrasonic inversion method simultaneously |
| CN110672047A (en) * | 2019-10-16 | 2020-01-10 | 江苏省特种设备安全监督检验研究院 | Laser ultrasonic measurement method for thickness of high-temperature metal material |
Non-Patent Citations (2)
| Title |
|---|
| GUOQUAN NIE ET.AL: "Effect of periodic corrugation on Lamb wave propagation in PMN-PT single crystal bilayer plates", 《ULTRASONICS》, vol. 108, 26 May 2020 (2020-05-26), pages 1 - 9, XP086266970, DOI: 10.1016/j.ultras.2020.106176 * |
| 潘蕾等: "基于超声Lamb波截止频率的双层薄板各层厚度表征", 《无损检测》, vol. 44, no. 6, 31 December 2022 (2022-12-31), pages 6 - 10 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114923442A (en) * | 2022-05-18 | 2022-08-19 | 南京理工大学 | Method and device for measuring thickness of each layer of double-layer thin plate based on ultrasonic Lamb wave zero group velocity resonance |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Huthwaite et al. | Mode selection for corrosion detection in pipes and vessels via guided wave tomography | |
| CN105651215A (en) | Coating thickness measuring method under unknown ultrasonic velocity condition | |
| CN101949894B (en) | Method for detecting interface contact strength by double frequency ultrasound | |
| CN103245311A (en) | Ultrasonic thickness measurement device and method for multilayered wave-absorbing coatings | |
| Luo et al. | Guided wave thickness measurement with EMATs | |
| CN103616439A (en) | Method for simultaneously measuring multiple parameters of linear visco-elastic thin layer material by employing ultrasonic flat probe | |
| CN106979761B (en) | Method for detecting thickness and surface morphology of each layer inside lithium ion battery | |
| Demčenko et al. | Ultrasonic measurements of undamaged concrete layer thickness in a deteriorated concrete structure | |
| Kusano et al. | Simultaneous sound velocity and thickness measurement by the ultrasonic pitch-catch method for corrosion-layer-forming polymeric materials | |
| CN113916165A (en) | Lamb wave thickness resonance method for measuring thickness of each layer of double-layer plate | |
| CA3110818A1 (en) | Continuous wave ultrasound or acoustic non-destructive testing | |
| Liu et al. | Air-coupled ultrasonic investigation of stacked cylindrical rods | |
| Ranjbar Naserabadi et al. | Ultrasonic high frequency lamb waves for evaluation of plate structures | |
| BR112021015095A2 (en) | METHOD AND DEVICE FOR NON-DESTRUCTIVE TESTING OF A SHEET MATERIAL | |
| CN106841385B (en) | Detection method based on sound-ultrasound polypropylene production pipeline powder coherent condition | |
| CN114923442A (en) | Method and device for measuring thickness of each layer of double-layer thin plate based on ultrasonic Lamb wave zero group velocity resonance | |
| CN112915452B (en) | Non-intrusive fire hydrant water pressure detection method based on multi-ultrasonic-signal time delay accumulation | |
| CN101806590B (en) | Method for using higher standing wave resonance for quantitatively detecting thickness of elastic plates | |
| Cobb et al. | Detecting sensitization in aluminum alloys using acoustic resonance and EMAT ultrasound | |
| Li et al. | Ultrasonic guided wave scattering matrices and tomography using sparse arrays for defect characterization | |
| CN112268959A (en) | Method for measuring ultrasonic plate wave attenuation coefficients at different temperatures | |
| Yeo et al. | Guided ultrasonic wave inspection of corrosion at ship hull structures | |
| Chen et al. | Parameter measurement of the cylindrically curved thin layer using low-frequency circumferential Lamb waves | |
| Faustmann et al. | Measurement of the properties of liquids based on the dispersion of Lamb waves in an acoustic waveguide | |
| Hou et al. | Ultrasonic Thickness Measurements of Thin-Walled Composite Steel Pipe |
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 | ||
| CB03 | Change of inventor or designer information | ||
| CB03 | Change of inventor or designer information |
Inventor after: Shen Zhonghua Inventor after: Pan Lei Inventor before: Pan Lei Inventor before: Shen Zhonghua |