CN103995059A - Acoustic surface wave flexible comb-shaped transducer applicable to curved surface detection - Google Patents
Acoustic surface wave flexible comb-shaped transducer applicable to curved surface detection Download PDFInfo
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- CN103995059A CN103995059A CN201410238778.6A CN201410238778A CN103995059A CN 103995059 A CN103995059 A CN 103995059A CN 201410238778 A CN201410238778 A CN 201410238778A CN 103995059 A CN103995059 A CN 103995059A
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Abstract
The invention relates to an acoustic surface wave flexible comb-shaped transducer which is an excitation/receiving integrated contact type ultrasonic transducer. The transducer comprises a plurality of strip-shaped piezoelectric vibrator comb-shaped arrays, a sound absorption filler, a backing sound absorption layer, a matching layer, a protecting film, a circuit board, a jacket, a coaxial cable, a connector and a cable fixing shell, wherein the flexible comb-shaped piezoelectric arrays, the flexible sound absorption filler, the flexible backing sound absorption layer, the flexible matching layer, the flexible protecting film and the flexible circuit board form a flexible transducer main body. Due to adoption of a flexible structure, the transducer is particularly applicable to rapid non-destructive detection on micro defects of any complex curved surface. The overall size of the transducer is not greater than 6mm*15mm*30mm in height, width and length, and the transducer can stretch into a small space or surfaces of components adhered to a sealed space, and thus rapid in-situ detection or embedded type detection is achieved.
Description
One, technical field
The present invention relates to a kind ofly for encouraging and receive the flexible comb transducer of surface acoustic wave, the quick nondestructive that is specially adapted to any complicated curved surface tiny flaw detects and embedded original position Non-Destructive Testing.
Two, background technology
Along with the develop rapidly of Design and manufacture ability, complex-curved zero member of each industrial circle a large amount of employings on the key components and parts of its key device.During the work of these zero members, be often subject to cyclic stress and temperature environment effect, the features such as that corrosivity is impacted is strong, longevity of service, very easily form surface fatigue crack defect in the course of work.Because it is bearing key effect conventionally in machine run, therefore in the manufacturing and in-service process of such complicated crucial zero member, need carry out strict Non-Destructive Testing and monitoring to its surface imperfection, to ensureing that the safe operation of each industrial circle key device is significant.
Due to such piece surface curvature not etc., surface topography is complicated, adopt traditional supersonic damage-free detection method to be difficult to realize its fast detecting, and testing cost increases greatly.When blade, wing class three-dimension curved surface part are detected, if adopt conventional ultrasound C scanning to detect, need to adopt 5 axle linkage devices to carry out scanning, can complete scanning detects, waste time and energy, detection efficiency is extremely low, cost is high, and surperficial blind area large, cannot complete detection go out crizzle.If adopt at present conventional Wedge type SAW transducer, because its wedge is that its size of rigidity is larger, cannot fit with curved surface, cannot guarantee the incident angle that encourages surface acoustic wave required, coupling effect is poor, detection signal energy conversion rate and detection sensitivity extreme difference.
Therefore, be badly in need of a kind of SAW transducer that can be applicable to complex-curved surface crack defect detection of exploitation, this transducer complicated curved surface of should be able to fitting, and have the features such as simple, volume is little are installed, can meet the quick or embedded original position Non-Destructive Testing demand on curved surface member surface.
State Intellectual Property Office discloses one piece of patent that publication number is CN103157594A: " a kind of flexible ultrasonic phased array array energy transducer and method for making ", this patent is examined state in actual effect at present, this patent has been described a kind of flexible ultrasonic phased array array energy transducer and preparation method thereof, and described transducer comprises flexible piezoelectric ceramic composite wafer, damping backing, matching layer, flexible circuit board, coaxial wire and probe interface; Described matching layer, flexible piezoelectric ceramic composite wafer and the damping backing formation acoustic stack that bonds together successively; Described flexible circuit board is connected with flexible piezoelectric ceramic composite wafer, and draws multicore coaxial cable line to described probe interface from flexible circuit board.Publication number is the patent of CN101152646A: " flexible ultrasonic transducer array and application apparatus thereof ", this patent is authorized at present, this patent has been described a kind of flexible ultrasonic transducer array, the ultrasonic transducer unit of this ultrasonic transducer, ultrasonic transmitter/ultrasound emission receiver, ultrasonic coupling medium, microprocessor, and flexible layer medium, this ultrasonic transducer unit is placed in this flexible layer medium with array format or surface and form flexible ultrasonic transducer array, the flexible ultrasonic transducer array various body parts with different surfaces shape of can fitting, thereby can obtain prior art ultrasonic therapy/ultrasonic imaging effect that is beyond one's reach.Above-mentioned two kinds of flexible array transducers are all to apply the pulse excitation with certain time-delay by the different piezoelectric vibrators unit in pair array, in tested sample inside, along the excitation of flexible layer normal orientation, there is longitudinal bulk wave of electron focusing scanning feature, and the surface acoustic wave that can not propagate along array arrangement direction in flexible layer in the excitation of tested sample surface.
Three, summary of the invention
The invention provides the flexible comb transducer of a kind of surface acoustic wave that is specially adapted to curved surface crack detection, there is the curved surface of can fitting, feature that thickness is little, can realize the quick or embedded original position Non-Destructive Testing of curved surface crack defect.
This SAW transducer at least comprises 2 above a plurality of bar shaped piezoelectric vibrators, is generally 4 to 8 bar shaped piezoelectric vibrators, and a plurality of bar shaped piezoelectric vibrator broad ways are arranged and formed comb arrays structure.Center distance w between each piezoelectric vibrator is measured material surface acoustic wave wavelength, i.e. the ratio of the measured material surface acoustic wave velocity of sound and transducer centre frequency.By all piezoelectric vibrators to transducer, apply electric excitation simultaneously, as recurrent pulse excitation or sinusoidal series excitation, encourage, on measured material surface, motivate the surface acoustic wave of propagating along array arrangement direction in flexible layer.
As shown in Figure 2; this SAW transducer comprise a plurality of bar shaped piezoelectric vibrators (1), positive and negative electrode (2), sound absorption filling material (3), backing absorbent treatment (4), matching layer (5), diaphragm (6), circuit board (7),, overcoat (8), cable fixed housing (9), concentric cable (10), joint (11); the regularly arranged formation array of a plurality of piezoelectric vibrators wherein, as shown in Figure 1.Piezoelectric vibrator adopts flexible piezoelectric ceramic composite, and sound absorption filling material, backing absorbent treatment, matching layer, diaphragm, circuit board and overcoat all adopt flexible material, to guarantee that transducer can adapt to curved surface, and laminating completely with it.
As shown in Figure 2, bar shaped flexible piezoelectric oscillator width d is 1/2nd of measured material surface acoustic wave wavelength, gap s between oscillator and oscillator is also 1/2nd of measured material surface acoustic wave wavelength, and the center distance w between oscillator and oscillator is measured material surface acoustic wave wavelength.Oscillator length l is 0.618 times of comb arrays total length D and rounds, and rounds [(center distance w * oscillator number n-oscillator gap s between oscillator) * 0.618] that is:, and general oscillator length l is no more than 10:1 with the ratio of width d.
This SAW transducer is contact transducer, during use, by couplant and tested sample surface, is coupled.This transducer is excitation/reception one transducer, can adopt cyclic pulse signal or sinusoidal string to encourage, detection system as shown in Figure 3, comprising: flexible SAW transducer, ultrasonic signal excitation receiving trap, AD converter, computing machine and tested sample.During detection, surface acoustic wave is propagated along specimen surface arrayed direction, while running into defect, can produce flaw echo, can judge whether to exist surface crack defect according to having or not of flaw echo.This transducer can detect the crack defect of tens microns of openings, an A sweep can complete the detection in specimen surface region as shown in Fig. 3 (12) dot-and-dash line scope, it is the detection within the scope of arrayed direction * oscillator length, only along oscillator length direction, carry out the detection that one-dimensional scanning can complete whole surface, can realize the complex-curved rapid scanning of variable curvature and detect.The defect reflection surface acoustic wave that the surface wave transducer that Fig. 4 is development receives.
Advantage of the present invention is:
1. the transducer of the present invention's development has flexible structure, is applicable to detect variable curvature complex-curved;
2. the transducer gross thickness of the present invention's development is no more than 6mm, can stretch into narrow space detects, and be specially adapted to embedded laminating and be arranged in the zero component surface in small space or enclosure space, to realize in situ detection or the Real-Time Monitoring of in-service of crucial rapid wear.
3. rapid scanning detects, and needs one-dimensional movement just can complete the detection of whole curved surface.
Four, accompanying drawing explanation
Fig. 1 is the flexible comb transducer one-piece construction of a kind of surface acoustic wave schematic diagram.
Fig. 2 is the flexible comb transducer composition diagram of a kind of surface acoustic wave.
Fig. 3 is the flexible comb transducer detection system of a kind of surface acoustic wave schematic diagram.
Fig. 4 is surface crack defect reflected sound surface wave signal.
Five, embodiment
This SAW transducer at least comprises 2 above a plurality of bar shaped piezoelectric vibrators, is generally 4 to 8 bar shaped piezoelectric vibrators, and a plurality of bar shaped piezoelectric vibrator broad ways are arranged and formed comb arrays structure.
Piezoelectric vibrator adopts flexible 1-3 type piezo-electric ceramic composite material.According to piezoelectric vibrator principle of design, piezoelectric vibrator layer is prepared as to the longitudinal vibration piezoelectric vibrator layer that centre frequency is expected frequency.Prepare flexible matching layer, its thickness is 1/4th of matching layer compressional wave wavelength.Flexible piezoelectric oscillator and the laminating of flexible matching layer are installed, formed piezoelectricity-coupling lamination.
Cutting piezoelectricity-coupling lamination, depth of cut is piezoelectric vibrator layer thickness, is about to piezoelectric vibrator layer and is cut into bar shaped piezoelectric vibrator comb arrays.As shown in Figure 2, bar shaped flexible piezoelectric oscillator width d is 1/2nd of measured material surface acoustic wave wavelength, gap s between oscillator and oscillator is also 1/2nd of measured material surface acoustic wave wavelength, center distance w between oscillator and oscillator is measured material surface acoustic wave wavelength, center distance w * oscillator number n-oscillator gap s between comb arrays total length D:(oscillator), oscillator length l is 0.618 times of comb arrays total length D and rounds, that is: round (comb arrays total length D * 0.618), general oscillator length l is no more than 10:1 with the ratio of width d.
The flexible backing absorbent treatment of fitting in comb arrays, and use flexible sound absorption packing material to fill gap between comb arrays, at matching layer outside laminating flexible protective film.At backing absorbent treatment outside laminating flexible PCB, and connecting electrode, the flexible comb transducer main body of surface acoustic wave formed.
As shown in Figure 1, wherein flexible PCB by the both positive and negative polarity of each bar shaped piezoelectric vibrator respectively parallel connection collect, form the both positive and negative polarity of transducer, and draw.
By the both positive and negative polarity welding of transducer both positive and negative polarity and concentric cable; flexible jacket is installed on other 5 surfaces in the flexible comb transducer main body of surface acoustic wave except diaphragm one side; and at flexible PCB and concentric cable junction, rigid cable fixed housing is installed, to protect tie point.For guaranteeing intact being fitted in curved surface of the flexible comb transducer main body energy of surface acoustic wave, between the flexible comb transducer body rim of surface acoustic wave and rigid cable fixed housing, should there is the flexible protective overcoat of certain width, width is generally 10～30mm.The last end welded and installed concentric cable standard universal joint at concentric cable, as BNC, SMA, UHF etc.
This SAW transducer can be as excitation/receive one transducer, or as excitation or the receiving transducer of surface acoustic wave.While detecting as excitation/receiving transducer, as shown in Figure 3, SAW transducer and the coupling of tested sample surface, be connected to ultrasonic signal excitation/receiving trap by transducer joint, and the signal output part of excitation/receiving trap connects oscillograph or connects computing machine through analog-digital commutator.Transducer, under the excitation of recurrent pulses or sinusoidal string signal, encourages at specimen surface the surface acoustic wave of propagating along array arrangement direction in flexible layer.Surface acoustic wave is propagated along specimen surface, after defect or marginal surface reflection, by transducer, is received, and through the pre-process of ultrasonic signal excitation/receiving trap, digiverter is converted into after digital signal, by computing machine, is shown as picture.Transducer, after surperficial one dimension scanning, can complete the fast detecting on tested sample surface.Transducer overall dimension is less than 15mm * 30mm, can go deep into small space or be mounted on the zero component surface of confined space, realizes quick in situ and detects or embedded detection.
Claims (8)
1. the flexible comb transducer of the surface acoustic wave that is specially adapted to curved surface crack detection, it is characterized in that: at least comprise 2 above a plurality of bar shaped piezoelectric vibrators, be generally 4 to 8 bar shaped piezoelectric vibrators, a plurality of bar shaped piezoelectric vibrator broad ways are arranged and are formed comb arrays structure.
2. the flexible comb transducer of surface acoustic wave according to claim 1; it is characterized in that: flexible piezoelectric ceramic composite piezoelectric vibrator comb arrays; flexible sound absorption filling material, flexible backing absorbent treatment, flexible matching layer, flexible protective film, flexible PCB and flexible jacket form the flexible structure of the flexible comb transducer of described surface acoustic wave; make its can with various curved surface good coupling, realize the detection of curved surface crack defect.
3. the flexible comb transducer of surface acoustic wave according to claim 1, it is characterized in that: the wiring in flexible PCB collects by the positive pole parallel connection of each bar shaped piezoelectric vibrator the positive pole, the negative pole parallel connection that form transducer and collects and form the negative pole of transducer and draw, by all piezoelectric vibrators to transducer comb arrays, apply electric excitation simultaneously, as recurrent pulse excitation or sinusoidal series excitation, encourage, on measured material surface, motivate the surface acoustic wave of propagating along arrayed direction.
4. the flexible comb transducer of surface acoustic wave according to claim 1, it is characterized in that: each bar shaped flexible piezoelectric oscillator width d of transducer comb arrays is 1/2nd of measured material surface acoustic wave wavelength, gap s between oscillator and oscillator is also 1/2nd of measured material surface acoustic wave wavelength, center distance w between oscillator and oscillator is measured material surface acoustic wave wavelength, center distance w * oscillator number n-oscillator gap s between comb arrays total length D:(oscillator), oscillator length l is 0.618 times of comb arrays total length D and rounds, that is: round (comb arrays total length D * 0.618), general oscillator length l is no more than 10:1 with the ratio of width d.
5. the flexible comb transducer of surface acoustic wave according to claim 1, is characterized in that: for protection flexible PCB pad is reliably connected with the lasting of concentric cable pad, at flexible PCB and concentric cable junction, rigid cable fixed housing is installed.
6. the flexible comb transducer of surface acoustic wave according to claim 1; it is characterized in that: for guaranteeing that transducer main body and curved surface fit completely; flexible protective is enclosed between flexible comb transducer body rim and rigid cable fixed housing has certain width, and width is generally 10～30mm.
7. the flexible comb transducer of surface acoustic wave according to claim 1, it is characterized in that: this transducer can detect the crack defect of tens microns of openings, an A sweep can complete specimen surface along the detection in arrayed direction overall dimensions * oscillator length regional extent, only along oscillator length direction, carry out the detection that one-dimensional scanning can complete whole surface, can realize the complex-curved rapid scanning of variable curvature and detect.
8. the flexible comb transducer of surface acoustic wave according to claim 1, it is characterized in that: transducer overall dimension is less than 6mm * 15mm * 30mm (thick * wide * long), can go deep into small space or be mounted on the zero component surface of confined space, realize quick in situ and detect or embedded detection.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105044205A (en) * | 2015-04-17 | 2015-11-11 | 北京理工大学 | Gas-liquid two-phase flow ultrasound flexibility array detection method based on probabilistic algorithmic |
| CN105548370A (en) * | 2016-01-29 | 2016-05-04 | 安徽理工大学 | Ultrasonic phased array probe for detecting curved surface workpiece |
| CN107335147A (en) * | 2017-06-29 | 2017-11-10 | 电子科技大学 | A kind of surface wave energy coupling head suitable for microwave physical therapy |
| CN109725057A (en) * | 2017-10-27 | 2019-05-07 | 奥林巴斯科技美国公司 | Ultrasonic scanner with interchangeable wedge piece and flexible detector |
| DE102018003803A1 (en) * | 2018-05-09 | 2019-11-14 | Diehl Metering Gmbh | Measuring device for determining a fluid size |
| CN112050839A (en) * | 2020-08-11 | 2020-12-08 | 大连理工大学 | Shape-following variable-curvature electromagnetic ultrasonic probe and measuring method thereof |
| CN112285202A (en) * | 2020-10-20 | 2021-01-29 | 天津大学 | Variable-curvature PBX surface crack oriented nondestructive testing method and sensor |
| CN114397369A (en) * | 2021-12-31 | 2022-04-26 | 临沂大学 | A can bury multidimensional acoustic emission sensor for concrete damage monitoring |
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Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105044205A (en) * | 2015-04-17 | 2015-11-11 | 北京理工大学 | Gas-liquid two-phase flow ultrasound flexibility array detection method based on probabilistic algorithmic |
| CN105548370A (en) * | 2016-01-29 | 2016-05-04 | 安徽理工大学 | Ultrasonic phased array probe for detecting curved surface workpiece |
| CN105548370B (en) * | 2016-01-29 | 2018-07-06 | 安徽理工大学 | A kind of ultrasonic phase array probe of detectable curve surface work pieces |
| CN107335147A (en) * | 2017-06-29 | 2017-11-10 | 电子科技大学 | A kind of surface wave energy coupling head suitable for microwave physical therapy |
| CN107335147B (en) * | 2017-06-29 | 2019-08-13 | 电子科技大学 | A kind of surface wave energy coupling head suitable for microwave physical therapy |
| CN109725057A (en) * | 2017-10-27 | 2019-05-07 | 奥林巴斯科技美国公司 | Ultrasonic scanner with interchangeable wedge piece and flexible detector |
| US11549918B2 (en) | 2017-10-27 | 2023-01-10 | Olympus America Inc. | Ultrasonic scanner with interchangeable wedge and flexible probe |
| DE102018003803A1 (en) * | 2018-05-09 | 2019-11-14 | Diehl Metering Gmbh | Measuring device for determining a fluid size |
| CN112050839A (en) * | 2020-08-11 | 2020-12-08 | 大连理工大学 | Shape-following variable-curvature electromagnetic ultrasonic probe and measuring method thereof |
| CN112285202A (en) * | 2020-10-20 | 2021-01-29 | 天津大学 | Variable-curvature PBX surface crack oriented nondestructive testing method and sensor |
| CN114397369A (en) * | 2021-12-31 | 2022-04-26 | 临沂大学 | A can bury multidimensional acoustic emission sensor for concrete damage monitoring |
| CN114397369B (en) * | 2021-12-31 | 2023-12-22 | 临沂大学 | A can embed multidimensional acoustic emission sensor for concrete damage monitoring |
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Application publication date: 20140820 |