CN110109122B - Device and method for detecting bottom target of solid plate based on leaky lamb wave - Google Patents
Device and method for detecting bottom target of solid plate based on leaky lamb wave Download PDFInfo
- Publication number
- CN110109122B CN110109122B CN201910451366.3A CN201910451366A CN110109122B CN 110109122 B CN110109122 B CN 110109122B CN 201910451366 A CN201910451366 A CN 201910451366A CN 110109122 B CN110109122 B CN 110109122B
- Authority
- CN
- China
- Prior art keywords
- solid plate
- ultrasonic transducer
- ultrasonic
- frequency
- 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.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
- G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
- G01S15/06—Systems determining the position data of a target
- G01S15/46—Indirect determination of position data
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
- G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
- G01S15/06—Systems determining the position data of a target
- G01S15/46—Indirect determination of position data
- G01S2015/465—Indirect determination of position data by Trilateration, i.e. two transducers determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the transducers, the position data of the target is determined
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Acoustics & Sound (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
The invention belongs to the technical field of ultrasonic detection equipment, and particularly relates to a device for detecting a target at the bottom of a solid plate based on leaky lamb waves, which comprises: a first signal emitter,The ultrasonic diagnosis device comprises a first oscilloscope, a first ultrasonic transducer (1), a second signal emitter, a second oscilloscope, a second ultrasonic transducer (2), a solid plate (5) and a data processing module; the solid plate bottom target (3) is arranged below the solid plate (5), the first ultrasonic transducer (1) and the second ultrasonic transducer (2) are oppositely arranged and arranged on the solid plate (5); the first ultrasonic transducer (1) and the second ultrasonic transducer (2) are inclined by an angle theta; the first ultrasonic transducer (1) is also sequentially connected with a first signal emitter and a first oscilloscope, and the second ultrasonic transducer (2) is also sequentially connected with a second signal emitter and a second oscilloscope; the data processing module is used for processing the data according to L1And L2The horizontal and vertical positions of the target (3) at the bottom of the solid plate are calculated.
Description
Technical Field
The invention belongs to the technical field of ultrasonic detection equipment, and particularly relates to a device and a method for detecting a bottom target of a solid plate based on leaky lamb waves.
Background
Lamb waves are guided waves formed in a solid plate, have frequency dispersion characteristics, and the relation between the phase (group) velocity and the frequency thickness product of each mode can be obtained through a Rayleigh-lamb frequency dispersion equation. Because attenuation is reduced in the lamb wave propagation process, the propagation distance is long, most of detection range can be covered in a short time, and the method is widely applied to the technical fields of nondestructive detection of large-area plates and shell structures, material thickness measurement and the like.
Currently, the bottom target of a solid plate is difficult to locate optically because light cannot penetrate the opaque solid plate. The existing acoustic method can penetrate opaque media and is widely applied to ocean exploration, nondestructive testing and the like. Thus, for the detection of the bottom target of the solid plate, acoustic methods may be employed. However, the acoustic measurement method based on one-pitch and one-pitch requires actual measurement of the specific situation under the solid plate point by point, and the incident body wave vertically penetrates through the single-layer plate, so that strong energy loss is caused. Therefore, the method for measuring the body wave in a transmitting-receiving mode has the problems of low efficiency, complex operation and the like.
Disclosure of Invention
The invention aims to solve the defects of the existing detection method, and provides a device and a method for detecting a target at the bottom of a solid plate based on leaky lamb waves, which can be used for positioning a cylindrical target at the bottom of the solid plate in the horizontal and vertical directions. Two ultrasonic transducers are used for respectively emitting ultrasonic waves to be incident into a solid plate immersed in water to generate the same lamb wave, and part of energy of the lamb wave leaks into surrounding water to form leaky lamb wave. Lamb wave energy leaking into the water will form two identical plane waves with angle theta, frequency f; the two plane waves respectively propagate to a cylindrical target position at the bottom of the solid plate and interact with the cylindrical target position to form two reflected waves with theta angle and frequency f. The two reflected waves are respectively reflected back to the solid plate to excite the same leaky lamb wave, and the leaky lamb wave returns to the corresponding original ultrasonic transducer along the original incident path and is received by the corresponding original ultrasonic transducer; the position of the cylindrical object at the bottom of the solid plate in the horizontal and vertical directions can be determined by the travel time of the returned reflected wave and the radius of the cylindrical object at the bottom of the solid plate.
In order to achieve the above object, the present invention provides a leaky lamb wave-based device for detecting a target at the bottom of a solid plate, which uses a pair of ultrasonic transducers arranged at two ends of the solid plate, and transmits ultrasonic waves towards the center of the solid plate at the same theta angle and frequency f in sequence, and the ultrasonic waves propagate to and interact with a cylindrical target position at the bottom of the solid plate to form a reflected wave with the theta angle and the frequency f. The reflected wave is reflected back to the solid plate to excite the same leaky lamb wave, and the leaky lamb wave returns to the original ultrasonic transducer along the original incident path and is received by the original ultrasonic transducer; the position of the cylindrical object at the bottom of the solid plate in the horizontal and vertical directions can be determined by the travel time of the returned reflected wave and the radius of the cylindrical object at the bottom of the solid plate.
The detection device specifically comprises: the ultrasonic diagnosis device comprises a first signal emitter, a first oscilloscope, a first ultrasonic transducer, a second signal emitter, a second oscilloscope, a second ultrasonic transducer, a solid plate and a data processing module;
the first ultrasonic transducer, the second ultrasonic transducer, the solid plate and the target at the bottom of the solid plate are all positioned below the water surface; the target at the bottom of the solid plate is arranged below the solid plate, the first ultrasonic transducer and the second ultrasonic transducer are oppositely arranged and are arranged on the solid plate, and the first ultrasonic transducer and the second ultrasonic transducer are separated from the solid plate by a distance Scm and are positioned on the same horizontal plane; the first ultrasonic transducer and the second ultrasonic transducer are both inclined by an angle theta; the first ultrasonic transducer is also sequentially connected with a first signal emitter and a first oscilloscope, and the second ultrasonic transducer is also sequentially connected with a second signal emitter and a second oscilloscope;
the data processing module is used for transmitting ultrasonic waves with the angle theta and the frequency f transmitted by the first ultrasonic transducer in the solid plate according to the propagation distance L of the ultrasonic waves in the solid plate1And the distance L of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer to propagate in the solid plate2Calculating the horizontal position and the vertical position of the target at the bottom of the solid plate; wherein the solid plate bottom target is a cylindrical target.
As one improvement of the above technical solution, θ ═ arcsin (Cw/Cp), where Cp is the phase velocity of the lamb wave; cw is the speed of sound.
As one improvement of the above technical solution, the solid plate is an opaque metal plate; preferably an aluminium plate.
As an improvement of the above technical solution, the data processing module specifically includes:
a first data receiving unit for receiving the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the first ultrasonic transducer in the solid plate1；
A first processing unit for propagating in the solid plate according to the ultrasonic wave of theta angle and frequency f emitted by the first ultrasonic transducerTime t1(ii) a Calculating the propagation distance L of the sound wave with the angle of the ultrasonic theta and the frequency f emitted by the first ultrasonic transducer in the solid plate1；
L1＝Cw·t0·sinθ+Cg·(t1-2t0)/2 (1)
Wherein, t0Time of propagation of ultrasonic waves in water, t0(ii) S/Cw; cg is the group velocity of lamb waves; cw is the sound velocity; θ ═ arcsin (Cw/Cp), where Cp is the phase velocity of the lamb wave; t is t1The propagation time of the reflected leaky lamb wave received by the first ultrasonic energy transducer;
a second data receiving unit for receiving the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer in the solid plate2；
A second processing unit for propagating the ultrasonic waves with the frequency f in the solid plate according to the angle theta emitted by the second ultrasonic transducer for a time t2(ii) a Calculating the propagation distance L of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer in the solid plate2；
L2＝Cw·t0·sinθ+Cg·(t2-2t0)/2 (2)
Wherein, t1The propagation time of the reflected leaky lamb wave received by the second ultrasonic transducer;
a third processing unit for processing according to L1And L2Calculating the horizontal position D and the vertical position h of the target at the bottom of the solid plate;
wherein L is the distance between the first ultrasonic transducer and the second ultrasonic transducer; r is the radius of the solid plate bottom target.
Based on the device for detecting the bottom target of the solid plate based on the leaky lamb wave, the invention also provides a method for detecting the bottom target of the solid plate based on the leaky lamb wave. The method specifically comprises the following steps:
acquiring the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the first ultrasonic transducer in the solid plate1；
Acquiring the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer in the solid plate2；
According to t1And t2Calculating the propagation distance L of the ultrasonic wave with the angle theta and the frequency f emitted by the first ultrasonic transducer in the solid plate correspondingly1And the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer propagates in the solid plate for a distance L2；
According to L1And L2And calculating the horizontal position D and the vertical position h of the target at the bottom of the solid plate.
As one improvement of the technical scheme, the acquisition of the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the first ultrasonic transducer in the solid plate1(ii) a The method specifically comprises the following steps:
the first signal emitter emits an electric signal to the first ultrasonic transducer, the first ultrasonic transducer converts the electric signal into ultrasonic waves, and the ultrasonic waves with the angle of an incident angle theta and the frequency f are emitted into a solid plate immersed in water to form lamb waves; the leaky lamb waves leaked into water are incident on the outer surface of a target at the bottom of the solid plate in a theta angle and frequency f plane wave and interact with the target at the bottom of the solid plate to form a reflected wave with the theta angle and the frequency f, the reflected wave is reflected back to the solid plate through the outer surface of the target at the bottom of the solid plate to excite the same leaky lamb waves and returns to the first ultrasonic transducer through the solid plate along the original incident path, the first ultrasonic transducer receives the reflected leaky lamb waves and displays the reflected leaky lamb waves and the propagation time t thereof through the first oscilloscope1。
As the above-mentioned skillOne improvement of the technical scheme is that the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer in the solid plate is obtained2(ii) a The method specifically comprises the following steps:
the second signal emitter emits an electric signal to the second ultrasonic transducer, the second ultrasonic transducer converts the electric signal into ultrasonic waves, and the ultrasonic waves with the angle of an incident angle theta and the frequency f are emitted into a solid plate immersed in water to form lamb waves; the leaky lamb waves leaked into the water are incident on the outer surface of the solid plate bottom target in a theta angle and frequency f plane wave and interact with the solid plate bottom target to form a reflected wave with the theta angle and the frequency f, the reflected wave is reflected back to the solid plate through the outer surface of the solid plate bottom target to excite the same leaky lamb waves and returns to the second ultrasonic transducer through the solid plate along the original incident path, the second ultrasonic transducer receives the reflected leaky lamb waves and displays the reflected leaky lamb waves and the propagation time t thereof through the second oscilloscope2。
As one improvement of the above technical solution, the above is according to t1And t2Calculating the propagation distance L of the ultrasonic wave with the angle theta and the frequency f emitted by the first ultrasonic transducer in the solid plate correspondingly1And the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer propagates in the solid plate for a distance L2(ii) a The method specifically comprises the following steps:
the angle theta and the frequency f ultrasonic wave emitted by the first ultrasonic transducer are propagated in the solid plate by a distance L1Comprises the following steps:
L1＝Cw·t0·sinθ+Cg·(t1-2t0)/2 (1)
wherein, t0Time of propagation of ultrasonic waves in water, t0(ii) S/Cw; cg is the group velocity of lamb waves; cw is the sound velocity; θ ═ arcsin (Cw/Cp), where Cp is the phase velocity of the lamb wave; t is t1The propagation time of the reflected leaky lamb wave received by the first ultrasonic energy transducer;
the distance L of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer propagating in the solid plate2Comprises the following steps:
L2＝Cw·t0·sinθ+Cg·(t2-2t0)/2 (2)
wherein, t1Is the propagation time of the reflected leaky lamb wave received by the second ultrasonic transducer.
As one improvement of the above technical solution, said base according to L1And L2Calculating the horizontal position D and the vertical position h of the target at the bottom of the solid plate; the method specifically comprises the following steps:
wherein L is the distance between the first ultrasonic transducer and the second ultrasonic transducer; r is the radius of the solid plate bottom target.
Compared with the prior art, the invention has the beneficial effects that:
the method can calculate the horizontal position and the vertical position of the target at the bottom of the solid plate in a short time, determine the specific position of the target at the bottom of the solid plate, and realize the quick and accurate positioning of the target at the bottom of the solid plate.
Drawings
FIG. 1 is a schematic structural diagram of an apparatus for detecting a target at the bottom of a solid plate based on leaky lamb waves according to the present invention;
FIG. 2 is a schematic structural diagram of a first ultrasonic transducer, a second ultrasonic transducer, a solid plate and a cylindrical target in the device for detecting the target at the bottom of the solid plate based on leaky lamb waves, which is disclosed by the invention, immersed in the water surface;
FIG. 3 is a phase velocity dispersion curve of a solid plate in an apparatus for detecting a target at the bottom of the solid plate based on leaky lamb waves according to the invention, wherein A0, S0, A1, S1, A2, S2 are respective lamb wave modes;
FIG. 4 is a group velocity dispersion curve of a solid plate in an apparatus for detecting a target at the bottom of the solid plate based on leaky lamb waves according to the invention, wherein A0, S0, A1, S1, A2, S2 are respective lamb wave modes;
FIG. 5 is a graph of the attenuation dispersion of a solid plate in an apparatus for detecting a target at the bottom of the solid plate based on leaky lamb waves according to the invention, wherein A0, S0, A1, S1, A2, S2 are respective lamb wave modes;
FIG. 6 is a graph of time versus relative amplitude of reflected waves received by a first ultrasonic transducer in an apparatus for detecting a target at the bottom of a solid plate based on leaky lamb waves of the present invention, recording the propagation time t 1;
FIG. 7 is a graph of time versus relative amplitude of reflected waves received by a second ultrasonic transducer in an apparatus for detecting a target at the bottom of a solid plate based on leaky lamb waves of the present invention, recording the travel time t 2.
Reference numerals:
1. first ultrasonic transducer 2 and second ultrasonic transducer
3. Cylindrical target 4, water surface
5. Solid plate 6, container
Detailed Description
The invention will now be further described with reference to the accompanying drawings.
As shown in figures 1 and 2, the invention provides a device for detecting a target at the bottom of a solid plate based on leaky lamb waves, wherein a part of the device is placed in a container containing water, the device adopts a pair of ultrasonic transducers arranged at two ends of the solid plate, ultrasonic waves are respectively emitted towards the center of the solid plate at the same theta angle and frequency f in sequence, and are transmitted to a cylindrical target position at the bottom of the solid plate and interact with the cylindrical target position to form a reflected wave with the theta angle and the frequency f. The reflected wave is reflected back to the solid plate to excite the same leaky lamb wave, and the leaky lamb wave returns to the original ultrasonic transducer along the original incident path and is received by the original ultrasonic transducer; the position of the cylindrical object at the bottom of the solid plate in the horizontal and vertical directions can be determined by the travel time of the returned reflected wave and the radius of the cylindrical object at the bottom of the solid plate.
The detection device specifically comprises: the ultrasonic diagnosis device comprises a first signal emitter, a first oscilloscope, a first ultrasonic transducer 1, a second signal emitter, a second oscilloscope, a second ultrasonic transducer 2, a solid plate 5 and a data processing module;
the first ultrasonic transducer 1, the second ultrasonic transducer 2, the solid plate 5 and the solid plate bottom target 3 are all positioned in a container 6 with water, namely below the water surface 4; the solid plate bottom target 3 is placed below the solid plate 5, the first ultrasonic transducer 1 and the second ultrasonic transducer 2 are oppositely placed, the first ultrasonic transducer and the second ultrasonic transducer are placed above the solid plate 5, and the first ultrasonic transducer and the second ultrasonic transducer are positioned on the same horizontal plane and are separated from the solid plate 5 by a distance Scm; the first ultrasonic transducer 1 and the second ultrasonic transducer 2 are both inclined by an angle theta; the first ultrasonic transducer 1 is also sequentially connected with a first signal emitter and a first oscilloscope, and the second ultrasonic transducer 2 is also sequentially connected with a second signal emitter and a second oscilloscope;
the data processing module is used for transmitting ultrasonic waves with the angle theta and the frequency f in accordance with the first ultrasonic transducer 1 and transmitting the ultrasonic waves with the distance L in the solid plate 51And the distance L of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer 2 to propagate in the solid plate 52And calculating the horizontal position and the vertical position of the target 3 at the bottom of the solid plate to finish detecting the specific position of the target 3 at the bottom of the solid plate.
Wherein, if the functions in the data processing module are implemented in the form of software functional units and sold or used as independent products, the functions can be stored in a nonvolatile computer readable storage medium which can be executed by a processor. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
Wherein θ is arcsin (Cw/Cp), where Cp is a phase velocity of the lamb wave; cw is the speed of sound.
The solid plate is an opaque metal plate; preferably an aluminium plate.
The data processing module specifically comprises:
a first data receiving unit for receiving the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the first ultrasonic transducer 1 in the solid plate 51；
A first processing unit for propagating ultrasonic waves of frequency f in the solid plate 5 according to the angle theta emitted by the first ultrasonic transducer 1 for a time t1(ii) a Calculating the distance L of propagation of the ultrasonic wave emitted by the first ultrasonic transducer 1 at the angle theta and the frequency f in the solid plate 51；
L1＝Cw·t0·sinθ+Cg·(t1-2t0)/2 (1)
Wherein, t0Time of propagation of ultrasonic waves in water, t0(ii) S/Cw; cg is the group velocity of lamb waves; cw is the sound velocity; θ ═ arcsin (Cw/Cp), where Cp is the phase velocity of the lamb wave; t is t1The propagation time of the reflected leaky lamb wave received by the first ultrasonic energy transducer;
a second data receiving unit for receiving the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer 2 in the solid plate 52；
A second processing unit for propagating the ultrasonic waves of frequency f in the solid plate 5 for a time t according to the angle theta emitted by the second ultrasonic transducer 22(ii) a Calculating the distance L of propagation of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer 2 in the solid plate 52；
L2＝Cw·t0·sinθ+Cg·(t2-2t0)/2 (2)
Wherein, t1Upon propagation of the reflected leaky lamb wave received by the second ultrasonic transducerA (c) is added;
a third processing unit for processing according to L1And L2Calculating the horizontal position D and the vertical position h of the target at the bottom of the solid plate;
wherein L is the distance between the first ultrasonic transducer and the second ultrasonic transducer; r is the radius of the solid plate bottom target.
Based on the device for detecting the target at the bottom of the solid plate based on the leaky lamb wave, the invention also provides a method for detecting the target at the bottom of the solid plate based on the leaky lamb wave. The method specifically comprises the following steps:
assuming a longitudinal wave velocity Cl, a transverse wave velocity Cs and a density rho of the solid plate material1Plate thickness d of solid plate material, density ρ of liquid2Sound velocity Cw, lamb wave number k and lamb wave frequency omega according to a frequency dispersion equation of the immersion liquid plate:
wherein k isLomega/Cl is the wave number of longitudinal waves in the solid plate; k is a radical ofTomega/Cs is the wave number of the transverse wave of the body;
i is an imaginary part; wherein coth () is a hyperbolic cotangent function; tanh () is a hyperbolic tangent function;
obtaining a phase velocity-frequency dispersion curve, a group velocity-frequency dispersion curve and an attenuation-frequency dispersion curve of an S-series lamb mode of a leaky lamb wave in the immersion liquid solid plate according to the formula (5); specifically, as in fig. 3, 4 and 5, the dispersion curves of phase velocity-frequency, group velocity-frequency, and attenuation-frequency of the S0, S1, S2 lamb modes;
obtaining a phase velocity-frequency dispersion curve, a group velocity-frequency dispersion curve and an attenuation-frequency dispersion curve of an A series lamb mode of a leaky lamb wave in the immersion liquid solid plate according to the formula (6); specifically, as in fig. 3, 4 and 5, phase velocity-frequency dispersion curves, group velocity-frequency dispersion curves and attenuation-frequency dispersion curves for a0, a1, a2 lamb mode;
according to the obtained phase velocity-frequency dispersion curve, group velocity-frequency dispersion curve and attenuation-frequency dispersion curve of the A-series lamb mode, selecting the phase velocity-frequency dispersion curve, group velocity-frequency dispersion curve and attenuation-frequency dispersion curve of any A-series lamb mode, and determining the group velocity Cg and phase velocity Cp in the corresponding lamb mode according to the graphs shown in FIGS. 3, 4 and 5; based on the determined group velocity Cg and phase velocity Cp; determining an incidence angle theta of the ultrasonic wave by using theta as arcsin (Cw/Cp); based on the determined group velocity Cg and phase velocity Cp; determining the frequency f corresponding to the determined group velocity Cg and the phase velocity Cp; wherein the selected range of the frequency f of the ultrasonic wave is determined by the attenuation dispersion curve, e.g. selected A1The attenuation of the mode needs to satisfy the mode of being more than S0 and less than A1;
based on the determined angle theta and frequency f, acquiring the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the first ultrasonic transducer 1 in the solid plate 51(ii) a In particular, the amount of the solvent to be used,
the first signal emitter emits an electrical signal to the first ultrasonic transducer, the first ultrasonicThe transducer converts the electric signal into ultrasonic waves, and the ultrasonic waves with the angle of an incident angle theta and the frequency f are emitted into a solid plate immersed in water to form lamb waves; the leaky lamb waves leaked into water are incident on the outer surface of a target at the bottom of the solid plate in a theta angle and frequency f plane wave and interact with the target at the bottom of the solid plate to form a reflected wave with the theta angle and the frequency f, the reflected wave is reflected back to the solid plate through the outer surface of the target at the bottom of the solid plate to excite the same leaky lamb waves and returns to the first ultrasonic transducer through the solid plate along the original incident path, the first ultrasonic transducer receives the reflected leaky lamb waves and displays the reflected leaky lamb waves and the propagation time t thereof through the first oscilloscope1As shown in fig. 6.
Acquiring the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer in the solid plate2(ii) a The method specifically comprises the following steps:
the second signal emitter emits an electric signal to the second ultrasonic transducer, the second ultrasonic transducer converts the electric signal into ultrasonic waves, and the ultrasonic waves with the angle of an incident angle theta and the frequency f are emitted into a solid plate immersed in water to form lamb waves; the leaky lamb waves leaked into the water are incident on the outer surface of the solid plate bottom target in a theta angle and frequency f plane wave and interact with the solid plate bottom target to form a reflected wave with the theta angle and the frequency f, the reflected wave is reflected back to the solid plate through the outer surface of the solid plate bottom target to excite the same leaky lamb waves and returns to the second ultrasonic transducer through the solid plate along the original incident path, the second ultrasonic transducer receives the reflected leaky lamb waves and displays the reflected leaky lamb waves and the propagation time t thereof through the second oscilloscope2As shown in fig. 7.
According to t1And t2The distance L of propagation of the ultrasonic wave emitted by the first ultrasonic transducer 1 at the angle θ and the frequency f in the solid plate 5 is calculated correspondingly1And the ultrasonic wave of the angle theta and the frequency f emitted by the second ultrasonic transducer 2 propagates in the solid plate 5 by a distance L2(ii) a The method specifically comprises the following steps:
the ultrasonic wave with theta angle and frequency f emitted by the first ultrasonic transducerDistance L of propagation in a solid plate1Comprises the following steps:
L1＝Cw·t0·sinθ+Cg·(t1-2t0)/2 (1)
wherein, t0Time of propagation of ultrasonic waves in water, t0(ii) S/Cw; cg is the group velocity of lamb waves; cw is the sound velocity; θ ═ arcsin (Cw/Cp), where Cp is the phase velocity of the lamb wave; t is t1The propagation time of the reflected leaky lamb wave received by the first ultrasonic energy transducer;
the distance L of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer propagating in the solid plate2Comprises the following steps:
L2＝Cw·t0·sinθ+Cg·(t2-2t0)/2 (2)
wherein, t1The propagation time of the reflected leaky lamb wave received by the second ultrasonic transducer;
according to L1And L2Calculating the horizontal position D and the vertical position h of the target at the bottom of the solid plate; the method specifically comprises the following steps:
wherein L is the distance between the first ultrasonic transducer and the second ultrasonic transducer; r is the radius of the solid plate bottom target.
Example 1:
in this embodiment, the solid plate 5 is an aluminum plate, the target at the bottom of the solid plate is a steel cylinder target, and the present embodiment mainly verifies and detects the horizontal position and the vertical position of the steel cylinder target at the bottom of the aluminum plate, that is, the horizontal position D and the vertical position h of the steel cylinder target at the bottom of the aluminum plate can be determined by separating the aluminum plate, and the measurement method is simple and has high precision.
Wherein the longitudinal wave speed Cl of the aluminum plate is 6300m/s and the transverse wave speed Cl of the aluminum plate is 6300m/sSpeed Cs 3100m/s and density ρ1＝2700kg/m3The thickness d of the aluminum plate is 2.45mm, the sound velocity Cw in water is 1500m/s, and the density is rho2＝1000kg/m3。
By substituting the above plate and water information into the dispersion equation of the plate, the phase, group velocity and attenuation dispersion curve of leaky lamb waves in the immersion liquid solid plate can be solved, for example, fig. 3 is the phase velocity dispersion curve of the immersion liquid plate, fig. 4 is the group velocity dispersion curve of the immersion liquid plate, and fig. 5 is the attenuation dispersion curve of the immersion liquid plate.
As shown by the black dots in FIG. 3, we select A1The frequency of the mode is 1438kHz, and the point attenuation is larger than S0Mode, less than A1Mode(s). The group velocity Cg is 3235 m/s. The phase velocity Cp is 5488m/s, and the angle of incidence θ is given by: θ is arcsin (Cw/Cp) 15.86 °;
the height S of the first ultrasonic transducer 1 from the aluminum plate is 0.7cm, and the height S of the second ultrasonic transducer 2 from the aluminum plate is 0.7 cm; propagation time t of ultrasonic wave in water0A is generated in an aluminum plate using a first ultrasonic transducer 1, S/Cw 4.6 μ S1A mode leaky lamb wave is adopted, the first ultrasonic transducer 1 is adopted to receive an echo signal generated by the interaction with the steel cylinder target, and the propagation time t of the echo signal is recorded through a first oscilloscope142.79 μ s, and therefore, the distance L over which the ultrasonic wave emitted by the first ultrasonic transducer 1 propagates in the aluminum plate can be obtained1Comprises the following steps:
L1＝Cw·t0·sinθ+Cg·(t1-2t0)/2＝5.622cm
generating the same a in an aluminum plate using a second ultrasonic transducer 21Leaky lamb waves of a mode (the same refers to the condition that a second transducer is the same as the first transducer, and the A1 mode is different, and the mode refers to the same A1 mode), the second ultrasonic transducer 2 is adopted to receive echo signals generated by interaction with a steel column target, and the propagation time t of the echo signals is recorded through a second oscilloscope252.36 mus. It is thus possible to obtain the distance L over which the ultrasonic waves emitted by the second ultrasonic transducer 2 travel in the aluminum plate2Comprises the following steps:
L2＝Cw·t0·sinθ+Cg·(t2-2t0)/2＝7.170cm
wherein the radius of the steel cylinder target is 3.5cm, and the distance L between the two transducers is 10cm, so that the horizontal position D of the steel cylinder target can be determined as:
the vertical position h of the steel cylinder target can be expressed as:
and (4) judging the horizontal distance and the vertical distance of the steel cylinder target by taking the o point as an original point. Through actual measurement, the actual horizontal position and the vertical position of the steel column target are respectively as follows: d '4.430 ± 0.001cm, h' 0.315 ± 0.001 cm.
The actual horizontal position and the actual vertical position of the steel column target calculated by the method are respectively 4.226 cm; h is 0.329 cm; the positioning error of this method is 5% compared to the actual measurement result.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited. Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (6)
1. An apparatus for detecting a target at the bottom of a solid plate based on leaky lamb waves, comprising: the ultrasonic diagnosis device comprises a first signal emitter, a first oscilloscope, a first ultrasonic transducer (1), a second signal emitter, a second oscilloscope, a second ultrasonic transducer (2), a solid plate (5) and a data processing module;
the first ultrasonic transducer (1), the second ultrasonic transducer (2), the solid plate (5) and the solid plate bottom target (3) are all positioned under the water surface; the solid plate bottom target (3) is arranged below the solid plate (5), the first ultrasonic transducer (1) and the second ultrasonic transducer (2) are oppositely arranged and are arranged on the solid plate (5) and on the same horizontal plane; the first ultrasonic transducer (1) and the second ultrasonic transducer (2) are inclined by an angle theta; the first ultrasonic transducer (1) is also sequentially connected with a first signal emitter and a first oscilloscope, and the second ultrasonic transducer (2) is also sequentially connected with a second signal emitter and a second oscilloscope;
the data processing module is used for transmitting ultrasonic waves with a theta angle and a frequency f in accordance with the first ultrasonic transducer (1) and transmitting the ultrasonic waves with a distance L in the solid plate (5)1And the distance L of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer (2) to propagate in the solid plate (5)2Calculating the horizontal position and the vertical position of the target (3) at the bottom of the solid plate; wherein the solid plate bottom target (3) is a cylindrical target;
the data processing module specifically comprises:
a first data receiving unit for receiving the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the first ultrasonic transducer (1) in the solid plate (5)1；
A first processing unit for propagating the ultrasonic waves of frequency f in the solid plate (5) according to the angle theta emitted by the first ultrasonic transducer (1) for a time t1(ii) a Calculating the propagation distance L of the sound wave with theta angle and frequency f emitted by the first ultrasonic transducer (1) in the solid plate (5)1；
L1＝Cw·t0·sinθ+Cg·(t1-2t0)/2 (1)
Wherein, t0Time of propagation of ultrasonic waves in water, t0(ii) S/Cw; cg is the group velocity of lamb waves; s is the distance between the ultrasonic transducer and the fixing plate;
a second data receiving unit for receiving the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer (2) in the solid plate (5)2；
A second processing unit for processing the angle theta emitted by the second ultrasonic transducer (2)Propagation time t of ultrasonic waves of frequency f in the solid plate (5)2(ii) a Calculating the propagation distance L of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer (2) in the solid plate (5)2；
L2＝Cw·t0·sinθ+Cg·(t2-2t0)/2 (2)
A third processing unit for processing according to L1And L2Calculating the horizontal position D and the vertical position h of the target (3) at the bottom of the solid plate;
wherein L is the distance between the first ultrasonic transducer and the second ultrasonic transducer; r is the radius of the solid plate bottom target.
2. The leaky lamb wave-based device for detecting a solid plate bottom target as claimed in claim 1, wherein θ ═ arcsin (Cw/Cp); wherein Cp is the phase velocity of the lamb wave; cw is the speed of sound.
3. The leaky lamb wave based device for detecting targets on the bottom of a solid plate as claimed in claim 1, wherein the solid plate is an opaque metal plate.
4. A method for detecting a target at the bottom of a solid plate based on leaky lamb waves, which is implemented on the basis of the device as claimed in any one of claims 1 to 3, said method comprising:
acquiring the propagation time t of the ultrasonic wave with the angle theta and the frequency f emitted by the first ultrasonic transducer (1) in the solid plate (5)1；
Acquiring the theta angle and the frequency f of the ultrasonic wave emitted by the second ultrasonic transducer (2) to propagate in the solid plate (5)Time t2；
According to t1And t2The distance L of propagation of the ultrasonic wave with the angle theta and the frequency f emitted by the first ultrasonic transducer (1) in the solid plate (5) is calculated correspondingly1And the distance L of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer (2) in the solid plate (5)2；
Specifically, the angle theta and the frequency f ultrasonic waves emitted by the first ultrasonic transducer (1) propagate in the solid plate (5) by a distance L1Comprises the following steps:
L1＝Cw·t0·sinθ+Cg·(t1-2t0)/2 (1)
wherein, t0Time of propagation of ultrasonic waves in water, t0(ii) S/Cw; cg is the group velocity of lamb waves; s is the distance between the ultrasonic transducer and the fixing plate;
the distance L of the propagation of the ultrasonic wave with the angle theta and the frequency f emitted by the second ultrasonic transducer (2) in the solid plate (5)2Comprises the following steps:
L2＝Cw·t0·sinθ+Cg·(t2-2t0)/2 (2)
according to L1And L2Calculating the horizontal position D and the vertical position h of the target (3) at the bottom of the solid plate;
in particular, the amount of the solvent to be used,
wherein L is the distance between the first ultrasonic transducer and the second ultrasonic transducer; r is the radius of the solid plate bottom target.
5. The method of claim 4, wherein said obtaining the angle θ, frequency f ultrasonic waves emitted by the first ultrasonic transducer is at a solid plateMiddle propagation time t1(ii) a The method specifically comprises the following steps:
the first signal emitter emits an electric signal to the first ultrasonic transducer, the first ultrasonic transducer (1) converts the electric signal into ultrasonic waves, and the ultrasonic waves with the angle of an incident angle theta and the frequency f are emitted into a solid plate (5) immersed in water to form lamb waves; the leaky lamb waves leaked into water are incident on the outer surface of a solid plate bottom target at a theta angle and a plane wave with a frequency f and interact with the solid plate bottom target (3) to form a reflected wave with the theta angle and the frequency f, the reflected wave is reflected back to the solid plate (5) through the outer surface of the solid plate bottom target to excite the same leaky lamb waves and returns to the first ultrasonic transducer (1) along an original incident path through the solid plate (5), the first ultrasonic transducer (1) receives the reflected leaky lamb waves, and the reflected leaky lamb waves and the propagation time t of the reflected leaky lamb waves are displayed through the first oscilloscope1。
6. Method according to claim 4, wherein said obtaining of the time t of propagation in the solid plate of the ultrasonic waves emitted by the second ultrasonic transducer at angle θ and frequency f2(ii) a The method specifically comprises the following steps:
the second signal emitter emits an electric signal to the second ultrasonic transducer (2), the second ultrasonic transducer (2) converts the electric signal into ultrasonic waves, and the ultrasonic waves with the angle of an incident angle theta and the frequency f are emitted into a solid plate (5) immersed in water to form lamb waves; the leaky lamb waves leaked into the water are incident on the outer surface of the solid plate bottom target at a theta angle and a plane wave with a frequency f and interact with the solid plate bottom target (3) to form a reflected wave with the theta angle and the frequency f, the reflected wave is reflected back to the solid plate (5) through the outer surface of the solid plate bottom target to excite the same leaky lamb waves and returns to the second ultrasonic transducer (2) along an original incident path through the solid plate (5), the second ultrasonic transducer (2) receives the reflected leaky lamb waves, and the reflected leaky lamb waves and the propagation time t of the reflected leaky lamb waves are displayed through the second oscilloscope2。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910451366.3A CN110109122B (en) | 2019-05-28 | 2019-05-28 | Device and method for detecting bottom target of solid plate based on leaky lamb wave |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910451366.3A CN110109122B (en) | 2019-05-28 | 2019-05-28 | Device and method for detecting bottom target of solid plate based on leaky lamb wave |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110109122A CN110109122A (en) | 2019-08-09 |
| CN110109122B true CN110109122B (en) | 2021-02-09 |
Family
ID=67492593
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910451366.3A Active CN110109122B (en) | 2019-05-28 | 2019-05-28 | Device and method for detecting bottom target of solid plate based on leaky lamb wave |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110109122B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113295772B (en) * | 2021-06-09 | 2022-12-30 | 吉林大学 | Thin-walled tube nondestructive testing device and method based on ultrasonic leaky lamb waves |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102043016A (en) * | 2010-11-05 | 2011-05-04 | 上海交通大学 | Lamb wave-based autonomous damage identification imaging method |
| CN108254438A (en) * | 2017-12-19 | 2018-07-06 | 上海交通大学 | Uneven cross section structure non-destructive tests imaging method and system based on Lamb wave |
| WO2018204723A1 (en) * | 2017-05-04 | 2018-11-08 | The Board Of Trustees Of The Leland Stanford Junior University | Leaky lamb wave flowmeter |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10332457A1 (en) * | 2003-07-16 | 2005-02-10 | Technische Universität Darmstadt | Positioning method for determining the position of a moving object uses automatic evaluation of runtime measurements during a three-dimensional diffusion of waves |
| CN101206010B (en) * | 2007-12-14 | 2011-06-22 | 济南大学 | Pipe jar destruction positioning system based on sound wave synergic detection and positioning method thereof |
| JP2011013967A (en) * | 2009-07-02 | 2011-01-20 | Toshiba Corp | Stiffness detector, stiffness detection method and paper sheet processor including the stiffness detector |
| CN101923074B (en) * | 2010-07-29 | 2012-01-11 | 国营江北机械厂 | Ultrasonic detection method of ultrahigh-strength steel thin-wall spinning cylinder |
| CN203249605U (en) * | 2013-04-19 | 2013-10-23 | 北京工业大学 | Longitudinal guided wave-based heat carrier furnace pipeline carbon deposit quantity tester |
| US20160209539A1 (en) * | 2014-11-14 | 2016-07-21 | Schlumberger Technology Corporation | Method for Separating Multi-Modal Acoustic Measurements for Evaluating Multilayer Structures |
| JP6317708B2 (en) * | 2015-06-12 | 2018-04-25 | 株式会社Ｓｕｂａｒｕ | Ultrasonic flaw detection system, ultrasonic flaw detection method, and aircraft structure |
| EP3115754B8 (en) * | 2015-07-06 | 2023-08-30 | ABB Schweiz AG | System and method for non-instrusive and continuous level measurement in a cylindrical vessel |
| CN109521092A (en) * | 2018-11-23 | 2019-03-26 | 侬泰轲（昆山）检测科技有限公司 | A kind of non-contact measurement apparatus and its method of surface wave and the Lamb wave velocity of sound |
-
2019
- 2019-05-28 CN CN201910451366.3A patent/CN110109122B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102043016A (en) * | 2010-11-05 | 2011-05-04 | 上海交通大学 | Lamb wave-based autonomous damage identification imaging method |
| WO2018204723A1 (en) * | 2017-05-04 | 2018-11-08 | The Board Of Trustees Of The Leland Stanford Junior University | Leaky lamb wave flowmeter |
| CN108254438A (en) * | 2017-12-19 | 2018-07-06 | 上海交通大学 | Uneven cross section structure non-destructive tests imaging method and system based on Lamb wave |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110109122A (en) | 2019-08-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4435984A (en) | Ultrasonic multiple-beam technique for detecting cracks in bimetallic or coarse-grained materials | |
| CN104808208B (en) | Measurement system and method for detecting orientation and size of underwater target on basis of laser sound source | |
| CN102539530B (en) | Method for measuring echo reduction/reflection coefficient of underwater sound passive material based on time reversal focusing | |
| CN110082428B (en) | Method for measuring elastic constant of material based on combination of crack tip effect and laser ultrasound | |
| Leighton et al. | Clutter suppression and classification using twin inverted pulse sonar (TWIPS) | |
| CN112362732B (en) | Free-form surface defect detection method and system based on laser ultrasonic elliptical imaging | |
| CN111624252A (en) | Method for improving Lamb wave phased array focusing detection speed | |
| CN110109122B (en) | Device and method for detecting bottom target of solid plate based on leaky lamb wave | |
| CN110109124B (en) | Device and method for sensing target at bottom of solid plate based on leaky lamb wave | |
| CN110554088A (en) | Air coupling ultrasonic detection method for defects | |
| JP2010054497A (en) | Ultrasonic flaw detection sensitivity setting method and ultrasonic flaw detector | |
| CN117191948A (en) | Ultrasonic leaky surface wave full-focusing imaging method based on virtual source | |
| Robert et al. | Assessment of real-time techniques for ultrasonic non-destructive testing | |
| US3592052A (en) | Ultrasonic crack depth measurement | |
| RU75060U1 (en) | ACOUSTIC LOCATION SYSTEM OF NEAR ACTION | |
| KR100662082B1 (en) | A method for radiation beam angle transform of ultrasonic waveguide sensor and an apparatus thereof | |
| Hayashi et al. | Defect detection using quasi-scholte wave for plate loaded with water on single surface | |
| CN113916991A (en) | Ultrasonic target for non-destructive inspection | |
| CN111256630A (en) | Method for rapidly measuring thickness of metal plate by utilizing electromagnetic ultrasonic guided wave frequency dispersion characteristic | |
| CN109974639B (en) | Solid plate thickness measuring device and method based on backward wave | |
| JPH095435A (en) | Underwater static object position measuring method | |
| US3290643A (en) | Simplified method of submarine depth determination | |
| RU98254U1 (en) | MULTI-FREQUENCY CORRELATION HYDROACOUSTIC LAG | |
| Hefner | Acoustic backscattering enhancements for circular elastic plates and acrylic targets, the application of acoustic holography to the study of scattering from planar elastic objects, and other research on the radiation of sound | |
| CN114777882A (en) | Container liquid level detection device based on wedge wave frequency dispersion |
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 |