CN111060600B - Sound beam focusing time delay control method for ultrasonic phased array imaging in pipeline - Google Patents
Sound beam focusing time delay control method for ultrasonic phased array imaging in pipeline Download PDFInfo
- Publication number
- CN111060600B CN111060600B CN201911244567.2A CN201911244567A CN111060600B CN 111060600 B CN111060600 B CN 111060600B CN 201911244567 A CN201911244567 A CN 201911244567A CN 111060600 B CN111060600 B CN 111060600B
- Authority
- CN
- China
- Prior art keywords
- phased array
- ultrasonic
- excitation
- focusing
- time delay
- 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.)
- Active
Links
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
- G01N29/04—Analysing solids
- G01N29/06—Visualisation of the interior, e.g. acoustic microscopy
- G01N29/0654—Imaging
- G01N29/0672—Imaging by acoustic tomography
-
- 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
- G01N29/22—Details, e.g. general constructional or apparatus details
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Acoustics & Sound (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
The invention relates to an acoustic beam focusing time delay control method for ultrasonic phased array imaging in a pipeline, which comprises the following steps: the method comprises the following steps: an ultrasonic phased array sensor arrangement. Step two: and (4) exciting and receiving the ultrasonic phased array sensor. Step three: considering any angle deflection in the field with the circular pipeline as the boundary, the time delay according to each channel is calculated. Step four: and distributing the time delay obtained by the calculation in the third step to each array element excitation channel of the ultrasonic phased array probe, delaying the same excitation electric signal for different time to generate excitation electric signals with equal amplitude and different phases, applying the excitation electric signals to each array element of the phased array probe to generate ultrasonic excitation with equal amplitude and different phases, and generating ultrasonic focusing waves with different focusing distances through superposition, cancellation and interference effects of the ultrasonic excitation electric signals to achieve effective control of focusing of any point sound beam in the pipeline.
Description
Technical Field
The invention belongs to the technical field of ultrasonic tomography, and relates to a time delay control method for sound beam focusing, which is used for solving the problems of errors and control failure caused by curved-surface pipe wall refraction in the ultrasonic phased array sound beam focusing process and realizing the visual test of high-precision sound field configuration and multi-phase medium distribution in a closed pipeline in the industrial process.
Background
Ultrasonic Tomography (UT) is a structural imaging technique that reconstructs refractive index, attenuation coefficient, or acoustic impedance distribution inside a field to be measured by arranging an array of Ultrasonic sensors outside the field to be measured and applying certain excitation to obtain boundary voltage measurement data. Compared with other soft-field imaging technologies such as Electrical Impedance Tomography (EIT) and Magnetic Tomography (MIT), UT has the advantages of non-invasiveness and high resolution, and compared with higher-precision hard-field imaging technologies such as X-ray Computed Tomography (X-CT) and Optical Tomography (OCT), UT is safe to use, simple in structure, and capable of realizing real-time imaging. In addition, the UT also has the advantages of non-contact, good directivity, low cost and the like, and is an ideal process visual detection monitoring means. The UT is used as a chromatographic imaging technical means and has wide application in multiphase flow visualization detection, chemical petroleum transportation, aircraft engine exploration and biomedical diagnosis.
The complete ultrasound tomography technique consists of three parts: designing, manufacturing and installing an ultrasonic transducer array; a signal excitation and acquisition system; and (4) an ultrasonic imaging image reconstruction algorithm. The ultrasonic transducer array consists of a plurality of single-wafer probes, the exciting probe converts a voltage signal into an acoustic signal through an inverse piezoelectric effect to form an exciting acoustic wave, and the receiving probe converts the sensed acoustic signal into an electric signal through the piezoelectric effect to send the electric signal to the detection system; the signal excitation and acquisition system sends a voltage excitation signal to the ultrasonic transducer, records, converts and demodulates a voltage detection signal generated by the ultrasonic transducer, and circularly excites the ultrasonic transducer at different positions through time sequence control; and the image reconstruction algorithm obtains effective measurement data of all the transducers under certain excitation by using the extracted measurement amplitude or the transit time obtained by demodulation, and obtains reasonable estimation of the distribution of the content medium in the field by using an image reconstruction method.
The traditional ultrasonic tomography technology based on the single wafer probe has certain limitations: the single crystal element probe transmits sound waves in a fan shape (cone shape), the scanning range is narrow, the side lobe attenuation is large under the condition of wide transmitting angle, the installation position and the direction of the single crystal element probe are fixed, and the dynamic configuration and the direction variable scanning of an excitation sound field cannot be realized. In addition: the ultrasonic tomography is heavily dependent on the number of field boundary transducers, and the image reconstruction process has serious ill-conditioned (small perturbation to the measured value can cause great change of the reconstruction result) and underdetermined (the number of equations to be solved is far less than the number of unknowns) under the condition of low transducer number. The development of ultrasound tomography is severely limited by the fixed excitation acoustic field format and the limited number of transducers. In order to realize high-precision and non-disturbance ultrasonic tomography visual test, tan super et al at Tianjin university propose a scanning tomography method based on ultrasonic plane waves in the patent ultrasonic plane wave scanning multiphase flow visual measurement device, sound beam control is carried out by controlling time delay of each array element in an ultrasonic phased array probe, a sound field is flexibly configured in an area which can not be detected by a traditional single-wafer probe, the quantity of projection data is greatly improved under the condition of not increasing an ultrasonic transducer, and image reconstruction quality is improved.
In the ultrasonic phased array acoustic beam focusing control algorithm, each array element is generally equivalent to a point sound source, time delay is added to an excitation signal of each channel to generate phase difference, and an excitation acoustic wave array surface of each array element is configured through the Huygens theorem to form a focusing acoustic beam with a variable aperture. The method is widely applied to the research of medical ultrasonic phased array imaging and industrial material nondestructive testing. However, in the industrial process, ultrasonic tomography generally faces a closed test field with a definite physical boundary (such as a pipe, a container, etc.), and the acoustic characteristics of media on both sides of the boundary are different, and a stronger acoustic impedance difference often exists. The sound wave is transmitted from the probe array element to the field region and needs to pass through the physical boundary and generate nonlinear effects such as amplitude attenuation, direction change and the like, so that the control effect of sound beam focusing time delay generates larger error and the control is invalid. Aiming at the common physical boundary of a circular pipeline in the industrial process, a sound beam focusing time delay control method aiming at the curved surface configuration of the circular pipeline is urgently needed, so that the dynamic focusing of sound beams can be realized in circular pipelines of different materials, thicknesses and diameters, and the aim of dynamically configuring and exciting a sound field with high precision is fulfilled.
Disclosure of Invention
The invention aims to provide an ultrasonic phased array acoustic beam focusing time delay control method based on travel time equality, aiming at the problem that the control of acoustic beam focusing time delay is invalid due to the fact that the control of the acoustic beam focusing time delay is large in error caused by a curved surface physical boundary represented by a circular pipeline. In circular pipelines of different materials, thicknesses and diameters, dynamic focusing of sound beams is achieved, and the purpose of dynamically configuring and exciting a sound field with high precision is achieved. The technical scheme is as follows:
an acoustic beam focusing time delay control method for ultrasonic phased array imaging in a circular pipeline comprises the following steps:
the method comprises the following steps: arranging ultrasonic phased array sensors: the ultrasonic phased array probes are embedded and installed on the outer wall of the circular pipeline, the surfaces of the ultrasonic phased array probes are parallel to the tangential direction of the outer wall of the circular pipeline, and are coupled with the outer wall of the circular pipeline by a coupling agent;
step two: excitation and reception of the ultrasonic phased array sensor: sequentially selecting ultrasonic phased array probes for excitation according to a cyclic excitation scheme; time delay control is carried out on M array element channels of the excitation phased array probe, so that the acoustic beam is focused at any distance in the field; meanwhile, all array elements of other phased array probes receive ultrasonic signals transmitted in the circular pipeline and analyze and process the signals; calculating a projection path based on the geometric position and the sound field configuration form, and recording and storing time-varying waveform data of the corresponding path;
step three: considering the axial random distance focusing in the field area with the circular pipeline as the boundary, selecting the array element number of the ultrasonic phased array probe as M, the array element pitch as s, and the thickness of the circular pipeline, namely the distance between the phased array probe and the physical boundary tangent line of the detected field area as DT 0 The axial focusing distance of the sound beam to be controlled is DF, the inner diameter of the circular pipeline is R, and the sound velocity of the circular pipeline is c 1 The sound velocity of the background medium in the measured field is c 2 Calculating the transition time delta t of the ith array element i_focus Expressed as follows:
according to the transit time Deltat i_focus Calculating the time delay t of each array element di_focus Expressed as follows:
t di_focus ＝max(Δt i_focus )-Δt i_focus
step four: and distributing the time delay obtained by the calculation in the third step to each array element excitation channel of the ultrasonic phased array probe, delaying the same excitation electric signal for different time, generating excitation electric signals with equal amplitude and different phases, applying the excitation electric signals to each array element of the phased array probe, generating ultrasonic excitation with equal amplitude and different phases, and generating ultrasonic focusing waves with different focusing distances through superposition, cancellation and interference effects of the ultrasonic excitation electric signals to effectively control the focusing of any point sound beam in the circular pipeline.
The invention provides an ultrasonic phased array sound beam focusing time delay control method based on equal travel time, aiming at the problem that sound beam focusing time delay control is invalid due to the fact that a curved surface physical boundary represented by a circular pipeline generates large errors, wherein refraction angles of sound sources at different positions at a curved surface interface are deduced by using Snell's law, then transit time when different array elements reach a selected focusing point is calculated according to the Huygens' theorem, and time delay information required by exciting channels of the array elements is reversely deduced according to the transit time. By using the method, the dynamic focusing of the sound beam can be realized in circular pipelines with different materials, thicknesses and diameters, the excitation sound field is configured in a dynamic high-precision manner, and the solving precision and the image resolution of the reconstruction result are obviously improved on the basis of meeting the real-time requirement of the industrial flow process.
Drawings
FIG. 1 is a schematic diagram of a basic test scheme and sensor arrangement for ultrasonic phased array tomography;
FIG. 2 is a schematic diagram of the ultrasonic phased array probe acoustic beam focusing control method in the presence of a circular pipe according to the present invention;
FIG. 3 is a graph comparing the focusing effect of sound beams using the method of the present invention and the general control method for different inner diameters of pipes;
Detailed Description
The invention discloses an acoustic beam focusing time delay control method for ultrasonic phased array imaging in a pipeline, which comprises the following steps:
the method comprises the following steps: an ultrasonic phased array sensor arrangement. Constitute ultrasonic sensor array by a plurality of ultrasonic phased array probes, every ultrasonic phased array probe is the linear array of compriseing fixed number array element, and each array element has the same performance parameter and all can independently encourage or receive, and all sensors are arranged along the equidistance of anticlockwise, and embedded the installing is at the pipeline outer wall, and the sensor surface all is on a parallel with pipeline outer wall tangential direction to carry out the coupling by the couplant with the pipeline outer wall.
Step two: and (4) exciting and receiving the ultrasonic phased array sensor. And sequentially selecting the ultrasonic phased array probes for excitation according to a cyclic excitation scheme. And performing time delay control on M array element channels of the excitation phased array probe to enable the acoustic beam to be focused at any distance in the field. Meanwhile, all array elements of other phased array probes receive ultrasonic signals transmitted in the pipeline and analyze and process the signals; and calculating a projection path based on the geometric position and the sound field configuration form, and recording and storing time-varying waveform data of the corresponding path.
Step three: considering the axial random distance focusing in the field area with the circular pipeline as the boundary, the array element number of the ultrasonic phased array probe is selected to be M, the array element pitch is selected to be s, and the distance between the thickness of the pipeline (the distance between the phased array probe and the physical boundary tangent line of the measured field area) is selected to be DT 0 The axial focusing distance of the sound beam (focusing distance in the pipeline) to be controlled is DF, the inner diameter of the pipeline is R, and the sound velocity of the pipeline is c 1 The sound velocity of the background medium in the measured field is c 2 . Calculating the transition time delta t of the ith array element i_focus Expressed as follows:
calculating the time delay t of each array element according to the time delay of each channel di_focus Expressed as follows:
t di_focus ＝max(Δt i_focus )-Δt i_focus
step four: distributing the time delay obtained by calculation in the third step to each array element excitation channel of the ultrasonic phased array probe, carrying out time delay on the same excitation electric signal for different time, generating excitation electric signals with equal amplitude and different phases, applying the excitation electric signals to each array element of the phased array probe, generating ultrasonic wave excitation with equal amplitude and different phases, and generating ultrasonic focusing waves with different focusing distances through superposition, cancellation and interference effects of the ultrasonic wave excitation and the excitation electric signals to achieve effective control of focusing of any point sound beam in the pipeline.
In the embodiment of the acoustic beam focusing time delay control method for ultrasonic phased array imaging in the circular pipeline, the method provided by the invention is used for controlling the acoustic beam focusing time delay of the ultrasonic phased array probe in a common application form of an ultrasonic tomography technology of oil-gas-water three-phase flow imaging in an industrial pipeline. The basic principle of ultrasonic phased array tomography and the operation steps and the improvement effect of the method provided by the invention are described in detail below by taking an ultrasonic phased array transducer array consisting of 8 16-array-element phased arrays as an example. The following examples are intended to be illustrative of embodiments of the invention and are not intended to be the only forms in which the present invention may be made or utilized, and other embodiments that perform the same function are also within the scope of the present invention.
FIG. 1 depicts the basic principle of ultrasonic phased array tomography using the method of the present invention, and depicts the mechanism of ultrasonic plane wave testing with water as the continuous phase and gas bubbles and oil bubbles as the discrete phases. When ultrasonic plane waves are formed between the excitation phased array probe and the receiving phased array probe, a test passage is formed between corresponding array elements of the transmission phased array probe and the receiving phased array probe, and oil-gas-water three-phase media in the test passage can generate different ultrasonic propagation modulation effects due to different densities. Due to the strong reflection effect of the bubbles on the ultrasound, incident waves are basically and completely reflected, and the size change of the bubbles can directly influence the ultrasound intensity reaching array elements at different positions of the receiving probe, so that the receiving amplitude of each array element is different, and accordingly, attenuation information corresponding to gas-liquid distribution in the ultrasound passage is obtained. In addition, because the propagation speeds of the ultrasonic waves in the oil phase medium and the water phase medium are different, the oil-water ratio between the corresponding array elements during the process that the ultrasonic plane waves emitted from the excitation phased array probe reach the receiving end does not directly influence the propagation time of the ultrasonic waves in the passage. Attenuation information and time delay information in the ultrasonic path are comprehensively utilized, and phase distribution reconstruction of a three-phase medium can be realized.
FIG. 2 illustrates the sound of the ultrasonic phased array probe embedded in the pipelineThe beam focusing control method is schematically shown. By controlling the emission delay time tau of each array element of the phased array probe, ultrasonic plane waves with variable directions can be formed in a measured field domain, and after the delay of the array elements is accurately calculated, an ultrasonic focused wave measuring space can be formed between the excitation ultrasonic phased array probe and other phased array probes. The number of array elements of the selected ultrasonic phased array probe is M =16, the pitch of the array elements is s =1.2mm, and the distance of the thickness of the pipeline (the distance from the phased array probe to the physical boundary tangent line of the field to be measured) is DT 0 =5mm, the beam axial focal distance to be controlled (in-duct focal distance) is DF =20mm. The inner diameters of the pipelines are respectively 200mm and 100mm, and the sound velocity of the pipeline is c 1 =2730m/s, and the sound velocity of the background medium in the measured field is c 2 ＝1480m/s。
Fig. 3 shows the difference of the sound beam focusing delay control effect by using the method of the present invention and the conventional method under different inner diameters of the pipes. The traditional time delay control method has the defects that the area of a focusing area is large, the error between the distance of the focusing area and the set axial focusing distance is large, and the control is invalid. The method can effectively focus at any axial distance of the probe in the field in the presence of pipelines with different pipe diameters, and has small area of a focusing area and small distance error; the acoustic beam grating lobes are effectively suppressed under the pipelines with different inner diameters.
The embodiments described above are some exemplary models of the present invention, and the present invention is not limited to the disclosure of the embodiments and the drawings. It is intended that all equivalents and modifications which do not depart from the spirit of the invention disclosed herein be protected.
Claims (1)
1. An acoustic beam focusing time delay control method for ultrasonic phased array imaging in a circular pipeline comprises the following steps:
the method comprises the following steps: ultrasonic phased array sensor arrangement: the ultrasonic phased array probes are embedded and installed on the outer wall of the circular pipeline, the surfaces of the ultrasonic phased array probes are parallel to the tangential direction of the outer wall of the circular pipeline, and are coupled with the outer wall of the circular pipeline by a coupling agent;
step two: excitation and reception of the ultrasonic phased array sensor: sequentially selecting ultrasonic phased array probes for excitation according to a cyclic excitation scheme; performing time delay control on M array element channels of the excitation phased array probe to enable the acoustic beam to be focused at any distance in the field; meanwhile, all array elements of other phased array probes receive ultrasonic signals transmitted in the circular pipeline and analyze and process the signals; calculating a projection path based on the geometric position and the sound field configuration form, and recording and storing time-varying waveform data of the corresponding path;
step three: considering the axial random distance focusing in the field area with the circular pipeline as the boundary, selecting the array element number of the ultrasonic phased array probe as M, the array element pitch as s, and the thickness of the circular pipeline, namely the distance between the phased array probe and the tangent line of the physical boundary of the field area to be measured as DT 0 The axial focusing distance of the sound beam to be controlled is DF, the inner diameter of the circular pipeline is R, and the sound velocity of the circular pipeline is c 1 The sound velocity of the background medium in the field to be measured is c 2 Calculating the transit time Deltat of the ith array element i_focus Expressed as follows:
according to the transit time Deltat i_focus Calculating time delay t of each array element di_focus Expressed as follows:
t di_focus ＝max(Δt i_focus )-Δt i_focus
step four: and distributing the time delay obtained by the calculation in the third step to each array element excitation channel of the ultrasonic phased array probe, delaying the same excitation electric signal for different time, generating excitation electric signals with equal amplitude and different phases, applying the excitation electric signals to each array element of the phased array probe, generating ultrasonic excitation with equal amplitude and different phases, and generating ultrasonic focusing waves with different focusing distances through superposition, cancellation and interference effects of the ultrasonic excitation electric signals to effectively control the focusing of any point sound beam in the circular pipeline.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911244567.2A CN111060600B (en) | 2019-12-06 | 2019-12-06 | Sound beam focusing time delay control method for ultrasonic phased array imaging in pipeline |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911244567.2A CN111060600B (en) | 2019-12-06 | 2019-12-06 | Sound beam focusing time delay control method for ultrasonic phased array imaging in pipeline |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111060600A CN111060600A (en) | 2020-04-24 |
| CN111060600B true CN111060600B (en) | 2022-10-18 |
Family
ID=70299979
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911244567.2A Active CN111060600B (en) | 2019-12-06 | 2019-12-06 | Sound beam focusing time delay control method for ultrasonic phased array imaging in pipeline |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111060600B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111665294A (en) * | 2020-07-02 | 2020-09-15 | 上海宝冶工程技术有限公司 | Method for detecting compactness of ski track of snow vehicle based on phased matrix ultrasound |
| CN112067691B (en) * | 2020-08-31 | 2024-01-30 | 天津大学 | Multi-frequency ultrasonic tomography method for combining attenuation spectrum of oil-gas-water three-phase medium |
| CN113188646A (en) * | 2021-03-19 | 2021-07-30 | 韶关东阳光自动化设备有限公司 | Planar full-electronic focusing HIFU phased array and test system thereof |
| CN113731942B (en) * | 2021-09-09 | 2022-08-26 | 南京大学 | Ultrasonic device for removing embolus in pipeline by phase control deflection focusing and control method |
| CN114047256B (en) * | 2021-10-25 | 2023-10-20 | 扬州大学 | Flat ceramic membrane defect ultrasonic imaging method based on dynamic array element synthetic aperture focusing |
| CN115068001B (en) * | 2022-08-12 | 2022-11-04 | 江苏霆升科技有限公司 | Ultrasonic imaging beam forming method and device, electronic equipment and medium |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB778166A (en) * | 1954-07-02 | 1957-07-03 | Babcock & Wilcox Ltd | Improvements in ultrasonic testing apparatus |
| CN201477076U (en) * | 2009-09-03 | 2010-05-19 | 北京主导时代科技有限公司 | Train wheel defect detection device adopting phased array probes |
| CN102830169A (en) * | 2011-06-13 | 2012-12-19 | 北京理工大学 | Simulation method for ultrasonic propagation of electronic encapsulation structure applied in ultrasonic microscopic detection |
| CN105044213B (en) * | 2015-06-28 | 2017-08-25 | 大连理工大学 | A kind of fiber-reinforced resin matrix compound material phased array ultrasonic detection chip postpones rule optimization method |
| CN108490068B (en) * | 2018-01-19 | 2020-12-04 | 天津大学 | Ultrasonic plane wave scanning type multiphase flow visual measuring device |
-
2019
- 2019-12-06 CN CN201911244567.2A patent/CN111060600B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN111060600A (en) | 2020-04-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111060600B (en) | Sound beam focusing time delay control method for ultrasonic phased array imaging in pipeline | |
| Guan et al. | Guided waves for damage identification in pipeline structures: A review | |
| Belanger et al. | Guided wave diffraction tomography within the born approximation | |
| US8170809B2 (en) | Guided waves for nondestructive testing of pipes | |
| Huthwaite et al. | Mode selection for corrosion detection in pipes and vessels via guided wave tomography | |
| Davies et al. | The application of synthetic focusing for imaging crack-like defects in pipelines using guided waves | |
| US7997139B2 (en) | Guided wave pipeline inspection system and method with enhanced natural focusing techniques | |
| Zhang et al. | Efficient immersion imaging of components with nonplanar surfaces | |
| US11022502B2 (en) | Ultrasonic waveguide technique for distribute sensing and measurements of physical and chemical properties of surrounding media | |
| JP6392331B2 (en) | Nondestructive absolute measurement of the thickness or depth of dielectric materials | |
| US20230003692A1 (en) | Passive measurement of acousto-elastic waves | |
| Brath et al. | Phased array imaging of complex-geometry composite components | |
| Lenz et al. | Measurement of the sound velocity in fluids using the echo signals from scattering particles | |
| Chen et al. | Ultrasonic inspection of curved structures with a hemispherical-omnidirectional ultrasonic probe via linear scan SAFT imaging | |
| CN111220709B (en) | Sound beam deflection time delay control method for ultrasonic phased array imaging in pipeline | |
| WO2020041891A1 (en) | Continuous wave ultrasound or acoustic non-destructive testing | |
| Davies | Inspection of pipes using low frequency focused guided waves | |
| Li | On circumferential disposition of pipe defects by long-range ultrasonic guided waves | |
| Weston | Advanced ultrasonic digital imaging and signal processing for applications in the field of non-destructive testing | |
| Vander Meulen et al. | Layer contributions to the nonlinear acoustic radiation from stratified media | |
| Mokhtari et al. | Polygonal damage shape reconstruction in plates using guided Lamb wave | |
| Massaad et al. | Design and Proof-of-Concept of a Matrix Transducer Array for Clamp-On Ultrasonic Flow Measurements | |
| Thon et al. | On the use of a linear array EMAT for remote thickness gauging using the reflected modes on a steel pipe | |
| Massaad et al. | Suppression of Lamb wave excitation via aperture control of a transducer array for ultrasonic clamp-on flow metering | |
| Hu et al. | An improved discrete elliptic imaging algorithm based on guided waves for defect localisation in curved plates |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |