CN118050426A - Simple fixture for measuring acoustic impedance of solid material by reflection method - Google Patents
Simple fixture for measuring acoustic impedance of solid material by reflection method Download PDFInfo
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- CN118050426A CN118050426A CN202311230947.7A CN202311230947A CN118050426A CN 118050426 A CN118050426 A CN 118050426A CN 202311230947 A CN202311230947 A CN 202311230947A CN 118050426 A CN118050426 A CN 118050426A
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- acoustic impedance
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- reflection method
- clamping cylinder
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- 238000001028 reflection method Methods 0.000 title claims abstract description 23
- 239000011343 solid material Substances 0.000 title claims abstract description 15
- 239000000523 sample Substances 0.000 claims abstract description 65
- 238000004891 communication Methods 0.000 claims abstract description 21
- 230000007246 mechanism Effects 0.000 claims abstract description 13
- 238000005259 measurement Methods 0.000 claims abstract description 3
- 230000008878 coupling Effects 0.000 claims 1
- 238000010168 coupling process Methods 0.000 claims 1
- 238000005859 coupling reaction Methods 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 19
- 238000012360 testing method Methods 0.000 abstract description 16
- 238000000034 method Methods 0.000 abstract description 12
- 239000000463 material Substances 0.000 abstract description 9
- 238000007654 immersion Methods 0.000 abstract description 5
- 230000008569 process Effects 0.000 abstract description 5
- 238000013461 design Methods 0.000 abstract description 4
- 238000001514 detection method Methods 0.000 abstract description 4
- 229910001220 stainless steel Inorganic materials 0.000 description 5
- 239000010935 stainless steel Substances 0.000 description 5
- 230000009471 action Effects 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000013074 reference sample Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
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
- G01N29/22—Details, e.g. general constructional or apparatus details
-
- 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
- G01N29/09—Analysing solids by measuring mechanical or acoustic impedance
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/01—Indexing codes associated with the measuring variable
- G01N2291/018—Impedance
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/023—Solids
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- 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 discloses a simple fixture for measuring acoustic impedance of a solid material by a reflection method, which relates to the technical field of transducer detection and comprises a connecting mechanism, wherein the connecting mechanism comprises a clamping cylinder, an extension groove is formed in the top of the clamping cylinder, a communication groove is formed in the bottom of the clamping cylinder, and the extension groove is communicated with the communication groove. The invention provides a fixture for measuring the acoustic impedance of a solid material by a water immersion type pulse echo reflection method, which is used for fixing the relative positions of an external probe and a sample to be measured, so that the system error is reduced, the repeatability of a test result is improved, the problem of repeatability deviation in the acoustic impedance measuring process by a reflection method is reduced, the requirement of engineering practice is met, the use is convenient, the method is simple and feasible, the stability of a test system is improved, the repeatability of the test result is improved, the requirement of engineering design is met, and the probe is conveniently connected and limited to facilitate comparison measurement, so that the acoustic impedance value of the test material is obtained.
Description
Technical Field
The invention relates to the technical field of transducer detection, in particular to a simple fixture for measuring acoustic impedance of a solid material by a reflection method.
Background
The structure of an ultrasonic transducer used in underwater acoustic detection, nondestructive detection and medical ultrasonic image diagnosis generally consists of a backing, a piezoelectric sheet, a matching layer and an acoustic lens, and in order to improve the sensitivity and bandwidth of the ultrasonic transducer, the following technology is generally adopted: the high-performance piezoelectric material is used, so that the transmitting and receiving capacity is enhanced, and the bandwidth is increased; the multi-layer acoustic impedance matching layer technology is used, so that loss in the transmission process is reduced, the bandwidth is widened, and in the acoustic design of the transducer, the backing material can be made of a high-impedance material, so that the high bandwidth can be obtained, but the sensitivity is reduced; low impedance materials can also be used, high sensitivity can be achieved, but bandwidth is sacrificed; the back lining and the matching layer are designed and manufactured, and the acoustic impedance of the material is measured;
In the test method, the acoustic impedance is measured by a reflection method conveniently and rapidly, a water immersion type pulse echo test system can be shared with a sound velocity and sound attenuation system, in engineering practice, the acoustic impedance is measured by the water immersion type pulse echo reflection method, namely, the repeatability is poor, the error is large, so that many engineers prefer to calculate the acoustic impedance by using a complicated method for measuring density and sound velocity, the relative positions of a sample and a test probe are kept unchanged when the reflection method is used for measuring the acoustic impedance twice before and after the reflection method, and if the angle is slightly deviated, the voltage change is large, which is a main source of poor repeatability; in addition, the offset of the relative distance can bring some errors, so that the test efficiency of the sounding impedance by the reflection method is reduced.
Disclosure of Invention
The invention aims to provide a simple clamp for measuring the acoustic impedance of a solid material by a reflection method, which has the advantage of reducing errors, and solves the problem of larger errors of measuring results before and after the acoustic impedance is measured by the reflection method.
In order to achieve the above purpose, the present invention provides the following technical solutions: the simple fixture for measuring the acoustic impedance of the solid material by using the reflection method comprises a connecting mechanism, wherein the connecting mechanism comprises a clamping cylinder, an extension groove is formed in the top of the clamping cylinder, a communication groove is formed in the bottom of the clamping cylinder, and the extension groove is communicated with the communication groove.
Preferably, the two sides of the top of the clamping cylinder are provided with vent holes, and one side of the surface of the clamping cylinder is provided with a fixing hole.
Preferably, the inner cavity of the vent hole is adhered with the interception net through adhesive, and the inner cavity of the fixing hole is connected with the fixing bolt in a threaded manner.
Preferably, the length of the extension groove is one third to one half of the length of the external probe for inserting the probe.
Preferably, the inner diameter of the communication groove is twice the outer diameter of the external probe, and the length of the communication groove is longer than the focal length of the external probe.
Preferably, the central axes of the extending groove and the communicating groove are perpendicular to the surface of the lower end, and the upper hole and the lower hole of the extending groove and the communicating groove are concentric.
Compared with the prior art, the invention has the following beneficial effects:
The invention provides a fixture for measuring the acoustic impedance of a solid material by a water immersion type pulse echo reflection method, which is used for fixing the relative positions of an external probe and a sample to be measured, so that the system error is reduced, the repeatability of a test result is improved, the problem of repeatability deviation in the acoustic impedance measuring process by a reflection method is reduced, the requirement of engineering practice is met, the use is convenient, the method is simple and feasible, the stability of a test system is improved, the repeatability of the test result is improved, the requirement of engineering design is met, and the probe is conveniently connected and limited to facilitate comparison measurement, so that the acoustic impedance value of the test material is obtained.
Drawings
FIG. 1 is a schematic diagram of the structure of the present invention;
FIG. 2 is a schematic top view of the cartridge of the present invention;
FIG. 3 is a schematic cross-sectional elevation view of a cartridge of the present invention;
Fig. 4 is a schematic side sectional structure of the cartridge of the present invention.
In the figure: 1. a connecting mechanism; 11. a clamping cylinder; 12. an extension groove; 13. a communication groove; 14. a vent hole; 15. a fixing hole; 2. an interception net; 3. and (5) fixing bolts.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The components of the connecting mechanism 1, the clamping cylinder 11, the extension groove 12, the communication groove 13, the vent hole 14, the fixing hole 15 and the interception net 2 are all universal standard components or components known to the skilled person, and the structure and the principle of the components are all known to the skilled person through technical manuals or through routine experimental methods.
Example 1
As shown in fig. 1-4, in a first embodiment of the present invention, a simple fixture for measuring acoustic impedance of solid materials by using a reflection method is provided, and the fixture comprises a connection mechanism 1, wherein the connection mechanism 1 comprises a clamping cylinder 11, an extension groove 12 is formed in the top of the clamping cylinder 11, a communication groove 13 is formed in the bottom of the clamping cylinder 11, and the extension groove 12 is communicated with the communication groove 13.
As shown in fig. 1 and 2, the connection mechanism 1 is composed of a metal cylinder, typically aluminum or stainless steel, preferably stainless steel, the diameter of the extension groove 12 is equal to the outer diameter of the probe, and the height of the inner cavity is typically one third to one half of the length of the probe, so that the probe can be inserted for convenient clamping; the communicating groove 13 at the lower end is thicker and is an acoustic wave channel, the inner diameter is at least 2 times of the outer diameter of the probe, the height of the communicating groove 13 is slightly larger than the focal length of the probe, the upper and lower extending grooves 12, the communicating groove 13 and the whole clamping cylinder 11 are concentric, wherein the axes are perpendicular to the surfaces of the extending grooves 12 and the communicating groove 13, in the acoustic impedance measuring operation, the measuring operation is carried out in two ways, one is to measure the density r of solid, then to measure the sound velocity c of solid, the acoustic impedance of the material is calculated through the formula Z=rc, the other is to measure the intensity of reflected waves of different interfaces, the acoustic velocity of the material is obtained through the substitution method, and the principle is as follows: sound waves are perpendicularly incident into the medium 2 from the medium 1, and at the interface, the sound pressure reflectivity r is: By utilizing the principle, in a degassing pure water tank, firstly, a standard sample block with known acoustic impedance Z1 is used, an ultrasonic probe vertically transmits sound waves to a sample, and then the same probe tests the reflected echo amplitude V1; then, replacing the standard sample block with a sample to be tested at the same position, wherein the acoustic impedance is Z2, testing the amplitude V2 of the reflected echo, setting the emission sound pressure of the test probe as p0, setting the amplitude V0 and setting the acoustic impedance of water as Z0; for the transducer, the converted voltage is proportional to the sound pressure, then there is/> The formula can be obtained: /(I)
Example 2
Referring to fig. 3-4, this embodiment is based on the previous embodiment, which is a second embodiment of the present invention.
In this embodiment, the inner cavity of the vent hole 14 is adhered with the interception net 2 through adhesive, and the inner cavity of the fixing hole 15 is in threaded connection with the fixing bolt 3.
Vent holes 14 are formed in two sides of the top of the clamping cylinder 11, and a fixing hole 15 is formed in one side of the surface of the clamping cylinder 11.
As shown in fig. 3-4, the surface of the clamping cylinder 11 is provided with a fixing hole 15, the probe can be fixed by using a fixing bolt 3, and the edge of the clamping cylinder is provided with two vent holes 14, so that air can escape conveniently, wherein the interception net 2 prevents external impurities from reversely entering the inner cavity of the vent holes 14 to cause blockage, and meanwhile, the probe is fixed by matching with the fixing hole 15.
Example 3
Referring to fig. 3-4, a third embodiment of the present invention is based on the first two embodiments.
In this embodiment, the extension slot 12 is one third to one half the length of the outer probe for insertion of the probe.
The inner diameter of the communication groove 13 is twice the outer diameter of the external probe, and the length of the communication groove 13 is longer than the focal length of the external probe.
The central axes of the extension groove 12 and the communication groove 13 are perpendicular to the surface of the lower end, and the upper and lower holes of the extension groove 12 and the communication groove 13 are concentric.
As shown in fig. 3-4, in the example, a 10MHz water immersion type focusing probe is used as the probe, the focal length is 30mm, the outer diameter of the probe is 12.90mm, and the length of the probe is 80mm, so that the diameter of the designed jig extension groove 12 is 12.92mm, and the height of the extension groove 12 is one quarter of the length of the probe, namely 20mm; the height of the communicating groove 13 is slightly longer than the focal length of 31mm; the inner diameter of the communication groove 13 is larger than 2 times of the outer diameter of the probe and is 30mm; the overall outer diameter of the clamping cylinder 11 is 40mm, the wall thickness of the clamping cylinder 11 is 5mm, the hole diameter of the vent hole 14 is 3mm, the processing is convenient, the diameter of the fixing hole 15 for fixing the probe is M3, the probe is exposed to about 1mm in the inner cavity of the communication groove 13 by extending to the inner diameter of the extension groove 12, and then a screw is screwed down to fix the probe; immersing in water, exhausting air from the cavity through the vent hole 14, removing some bubbles on the surface, measuring the stainless steel block L100×W100×T10, referring to the formulaV1 was found to be 0.517V; and measuring the diameter of the sample block by 50mm and the thickness of the sample block by 1.0mm to obtain V2 of 0.335V, using deaerated pure water in an external water tank and water temperature of 23.0 ℃, and calculating Z0 of 1.487MRayl and 45.4MRayl of stainless steel acoustic impedance by table lookup, so that the acoustic impedance of the sample is calculated to be 6.08MRayl, and repeatedly testing the sample at different water temperatures and different operators, wherein the value of the sample is 5.98-6.16, and the maximum deviation from the average value is 3%, thereby meeting the requirements of engineering test and design.
When the device is used, the surface flatness of a sample to be tested to be used needs to meet certain requirements, and the surface flatness is smaller than one tenth of wavelength: for example, at 2.5MHz, less than 0.06mm; and when 10MHz, the flatness is smaller than 0.015mm, and can be easily achieved by a common surface grinder, and the thickness of a sample to be measured is required to be larger than 4 wavelengths: for example, 2.5MHz, is greater than 2.40mm; when the frequency is 10MHz, the frequency is larger than 0.60mm, so that multiple echo signals on the upper surface and the lower surface of the sample can be distinguished, and in addition, the diameter of the sample is not smaller than the inner diameter of the extension groove 12, so that the jig can be conveniently placed;
Firstly, an external probe is inserted into an extension groove 12, the matching is tight, the surface of the probe just penetrates into the inner cavity of a lower communication groove 13 by about 1mm, then a fixing bolt 3 is used for extending to the inner cavity of a fixing hole 15 and is in threaded connection with the fixing bolt 3, the surface of the external probe is released, a clamping cylinder 11 and the external probe are fixedly screwed up, the external probe is immersed into a water tank, water is required to submerge a connecting mechanism 1, and air in the external probe is discharged through a blocking net 2 by a vent hole 14, so that no air bubble in the internal probe is ensured; placing a sample to be tested into the flat bottom of the external water tank; the connecting mechanism 1 is placed on the surface of a flat sample, and the relative position of the probe and the sample is maintained by the gravity of the clamping cylinder 11;
Obtaining the highest voltage V1 on a stainless steel block of a reference sample, and obtaining the highest voltage V2 on a sample to be detected; then the water temperature is measured, the density and sound speed of the water are obtained by looking up a table, The acoustic impedance of the water is calculated, the acoustic impedance Z0 of the water and the acoustic impedance Z1 of the reference sample are substituted into a formula, and the acoustic impedance Z of the sample is calculated.
Standard parts used in the file of the application can be purchased from market, and can be customized according to the description of the specification and the drawings, the specific connection modes of all parts adopt conventional means such as mature bolts, rivets, welding and the like in the prior art, the machinery, the parts and the equipment adopt conventional models in the prior art, the control mode is controlled automatically by a controller, a control circuit of the controller can be realized by simple programming of a person skilled in the art, the application belongs to common general knowledge in the art, and the application is mainly used for protecting mechanical devices, so the application does not explain the control mode and circuit connection in detail.
It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (6)
1. The utility model provides a simple and easy anchor clamps of reflection method measurement solid material acoustic impedance, includes coupling mechanism (1), its characterized in that: the connecting mechanism (1) comprises a clamping cylinder (11), an extension groove (12) is formed in the top of the clamping cylinder (11), a communication groove (13) is formed in the bottom of the clamping cylinder (11), and the extension groove (12) is communicated with the communication groove (13).
2. The simple fixture for measuring acoustic impedance of solid material by reflection method as claimed in claim 1, wherein: vent holes (14) are formed in two sides of the top of the clamping cylinder (11), and fixing holes (15) are formed in one side of the surface of the clamping cylinder (11).
3. The simple fixture for measuring acoustic impedance of solid material by reflection method as claimed in claim 2, wherein: the inner cavity of the fixing hole (15) is connected with a fixing bolt (2) through threads.
4. The simple fixture for measuring acoustic impedance of solid material by reflection method as claimed in claim 1, wherein: the length of the extension groove (12) is one third to one half of that of the external probe for inserting the probe.
5. The simple fixture for measuring acoustic impedance of solid material by reflection method as claimed in claim 1, wherein: the inner diameter of the communication groove (13) is twice as large as the outer diameter of the external probe, and the length of the communication groove (13) is longer than the focal length of the external probe.
6. The simple fixture for measuring acoustic impedance of solid material by reflection method as claimed in claim 1, wherein: the central axes of the extending groove (12) and the communicating groove (13) are perpendicular to the surface of the lower end, and the upper holes and the lower holes of the extending groove (12) and the communicating groove (13) are concentric.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311230947.7A CN118050426A (en) | 2023-09-22 | 2023-09-22 | Simple fixture for measuring acoustic impedance of solid material by reflection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311230947.7A CN118050426A (en) | 2023-09-22 | 2023-09-22 | Simple fixture for measuring acoustic impedance of solid material by reflection method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118050426A true CN118050426A (en) | 2024-05-17 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311230947.7A Pending CN118050426A (en) | 2023-09-22 | 2023-09-22 | Simple fixture for measuring acoustic impedance of solid material by reflection method |
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| Country | Link |
|---|---|
| CN (1) | CN118050426A (en) |
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2023
- 2023-09-22 CN CN202311230947.7A patent/CN118050426A/en active Pending
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