CN110501419A - A kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band - Google Patents
A kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band Download PDFInfo
- Publication number
- CN110501419A CN110501419A CN201910649886.5A CN201910649886A CN110501419A CN 110501419 A CN110501419 A CN 110501419A CN 201910649886 A CN201910649886 A CN 201910649886A CN 110501419 A CN110501419 A CN 110501419A
- Authority
- CN
- China
- Prior art keywords
- magnetic field
- tube
- uniform magnetic
- loading device
- axially adjustable
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
-
- 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
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/023—Solids
-
- 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
- G01N2291/26—Scanned objects
- G01N2291/269—Various geometry objects
- G01N2291/2698—Other discrete objects, e.g. bricks
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Acoustics & Sound (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The present invention relates to impedance tube sound insulation measurement technical field, the acoustic measurement system of specially a kind of axially adjustable uniform magnetic field loading device of band.It is made of impedance tube measuring system and axially adjustable uniform magnetic field loading device.Wherein the both ends of axially adjustable uniform magnetic field loading device are connected with the front tube rear end of impedance tube measuring system and rear pipe front end, are placed between front and rear tube, and axially concentric with front and rear tube.The front and rear tube upper surface of impedance tube measuring system is disposed with 6 sonic transducers, for receiving acoustical signal.Axial uniform magnetic field can be generated after energization in cylindrical tube, magnetic field size is quantitatively controlled by input current, while cylindrical tube is as the test specimen pipe for putting test specimen to be measured.The present invention can be under the premise of guaranteeing to test measurement accuracy, adjustable uniform magnetic field test environment needed for providing experiment.
Description
Technical field
The present invention relates to impedance tube sound insulation measurement technical field, specially a kind of axially adjustable uniform magnetic field load dress of band
The acoustic measurement system set.
Background technique
In modern society, noise is not only in the every field such as industry, aviation and traffic railway, to the instrument in its field
Device, equipment etc. bring serious security risk, and have seriously affected the daily work life of people.Traditional passive type sound insulation
Material once prepares completion, and equivalent parameters is fixed, and sound insulation frequency range is relatively narrow.Complicated acoustics is faced in order to enhance sound insulating material
The adaptability of environment, with magnetorheological equal materials and all kinds of active sound insulating materials based on magnetic field control are fast-developing, this kind of
Sound insulation experiment of the active sound insulating material under magnetic fields becomes one of problem to be solved.
Currently, one is annular permanent magnet is placed on resistance in impedance tube sound insulation experiment there are mainly three types of the loading methods of magnetic field
Anti- pipe, but this form magnetic field strength can not be adjusted effectively；Second is by electromagnetic field loading device and active sound insulating material one
It is same to be placed in impedance tube, on the one hand, conducting wire can not be drawn from impedance tube, and on the other hand, conducting wire is present in impedance tube, is to be measured
Test specimen periphery will certainly interfere the propagation of impedance tube inner plane wave, to produce a very large impact to sound insulation experiment；The third is straight
It connects the wound around coil on the outside of impedance tube and forms magnetic field loading device, since impedance tube acoustic sensor is closer from test specimen to be measured, around
The magnetic field and electric heating that the coil of system generates after being powered can produce bigger effect transducer sensitivity, and then influence sound insulation experiment
Measurement accuracy, and be inconvenient to test specimen of taking.
Summary of the invention
The present invention provides a kind of acoustic measurement systems of the axially adjustable uniform magnetic field loading device of band, by quantitatively changing
Become input current, uniform magnetic field rate of loading is adjusted, to reach the sound insulation requirement of experiment of active sound insulating material.
The technical scheme is that a kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band, by
Impedance tube measuring system and axially adjustable uniform magnetic field loading device composition.Wherein axially adjustable uniform magnetic field loading device
Both ends be connected with the front tube rear end of impedance tube measuring system and rear pipe front end, be placed between front and rear tube, and and front tube
It is axially concentric with rear pipe.Wherein, it is all 800mm that the front and rear tube of impedance tube measuring system is long, and surface layout has 6 on it
A sonic transducer, for receiving acoustical signal, first sensor is located at the 5mm of front tube rear end, and second sensor is located at the first sensing
8mm before device, 3rd sensor are located at 22mm before second sensor, after the 4th sensor is located at the 15mm of pipe front end, the 5th
Sensor is located at 8mm behind the 4th sensor, and the 6th sensor is located at 22mm behind the 5th sensor, guarantees 6 sensor positions
In same plane and point-blank, specific installation site is as shown in Fig. 1.Impedance tube measuring system sound source is installed on resistance
The front end of anti-pipe measuring system front tube.
Wherein, axially adjustable uniform magnetic field loading device is by cylindrical tube, coil baffle, enamel covered wire circle and direct current
Source composition；Enamel covered wire circle is equably wound in cylindrical tube, when coiling at the beginning and end of all reserve 500mm long
Enamel covered wire circle, for connecting DC power supply；Cylindrical tube both ends are provided with coil baffle, and coil can be in cylinder after being passed through electric current
Uniform magnetic field is generated in pipe, can be strong and weak by changing the intensity adjustment magnetic field of input current, while cylindrical tube is to be measured as putting
The piston rod of the test specimen pipe of test specimen, test specimen to be measured scale with a scale is pushed into cylindrical tube.Wherein, the graduated scale on piston rod can be with
Clearly represent the specific location that test specimen to be measured is located in cylindrical tube, i.e., graduated scale show how much, test specimen is just pushed into cylinder
Pipe how long distance.Graduated scale is installed on the surface of piston rod, guarantees that scale direction is vertical with the end face of piston rod, and live pushing
When stopper rod, scale position will not change.
In above scheme, the cylinder bore and the inside radius r of impedance tube measuring system are consistent, outer diameter and resistance
The outer radius R of anti-pipe measuring system is consistent, and length should be greater than 4r.The front and rear tube of cylindrical tube and impedance tube measuring system
Connection the connection types such as screw thread or buckle can be used, need to guarantee after connection interface fit closely and it is axial with one heart.
Further, not influence Distribution of Magnetic Field, the cylindrical tube is made of weak magnetic materials such as aluminium.
In above scheme, the enamel covered wire and DC power supply select the enamel-cover of different line footpaths according to required magnetic field size
The DC power supply of line and different capacity.
Further, the lesser enamel covered wire of line footpath can the more the number of turns of coiling, but resistance is larger, needs to select power at this time
Biggish DC power supply proposes requirements at the higher level to experimental facilities；The biggish enamel covered wire coiling the number of turns of line footpath is less, resistance compared with
It is small, larger current can be passed through to guarantee magnetic field strength, but this mode can generate larger electric heating.
Further, the enamel covered wire circle is often coated around one layer with insulating tape in coiling, it is reserved to
One section of enameled wire of DC power supply connection is wrapped up with insulating gum cover.
In above scheme, the coil baffle outer edge be should be higher than that around the enamel covered wire circle outermost made, coil gear
The thickness of plate guarantees indeformable in enamel covered wire circle winding process and in experimentation.
Further, the coil baffle is made of nylon material.
Further, the side such as threaded connection or glue connection can be used in the connection between the coil baffle and cylindrical tube
Formula.
In above scheme, to guarantee that during test specimen to be measured is pushed into cylindrical tube, described is with a scale not by effects of air pressure
The piston rod of scale has deflector hole, and the position of deflector hole is located at the front end face center that piston rod is contacted with test specimen and runs through
Entire piston rod.
Further, after to guarantee that test specimen to be measured is pushed into cylindrical tube, surface is vertical with plane wave, that is, guarantees test specimen to be measured
Vertically, smooth when and guarantee is pushed into, the piston rod radius of scale with a scale is less than r greater than 0.8r, and piston rod front end is adopted
It is designed with indent.
Further, the piston rod of scale with a scale can be used the materials such as nylon and be made.
The invention has the following advantages that
1, it can be realized uniform magnetic field load, magnetic field strength can quantitatively be adjusted by input current；
2, coil winding solves the problems, such as that conducting wire influences sound insulation measurement in impedance tube measuring system on the outside of cylindrical tube；
3, one section of cylindrical tube is increased, so that enamel covered wire circle range sensor is farther out, avoids in experiment magnetic field and electric heating to biography
The influence of sensor.
Detailed description of the invention
Fig. 1 is the acoustic measurement system with axially adjustable uniform magnetic field loading device.
Fig. 2 cylindrical tube.
The axially adjustable uniform magnetic field loading device of Fig. 3.
The piston rod of Fig. 4 scale with a scale.
Fig. 5 simulates the Distribution of Magnetic Field of axially adjustable uniform magnetic field loading device.
Fig. 6 surveys Distribution of Magnetic Field in cylindrical tube inner axis.
Fig. 7 impedance tube measuring system transformation front and back test result.
Description of symbols: 1- impedance tube measuring system sound source；2- impedance tube measuring system front tube；3- sonic transducer connects
Mouthful；The axially adjustable uniform magnetic field loading device of 4-；It is managed after 5- impedance tube measuring system；6- coil baffle；7- enamel covered wire circle；
8- graduated scale；9- deflector hole；First sensor is 3.；Second sensor is 2.；3rd sensor is 1.；4th sensor is 4.；5th
Sensor is 5.；6th sensor is 6..
Specific embodiment
Specific embodiments of the present invention will be further explained with reference to the accompanying drawing.
Cylindrical tube inside radius r=50mm in the present embodiment, outer radius R=60mm, length l=210mm, by aluminium material system
At seeing Fig. 2.
Enamel covered wire diameter is 1.2mm in the present embodiment, and coil turn is 1000 circles, and coil baffle is nylon material, thick
Spend 3mm.
In the present embodiment cylindrical tube with impedance tube measuring system front and rear tube by the way of being threadedly coupled, after connection such as
Shown in Fig. 1.
The present embodiment uses the " DC power supply of 60V, 60A ".
The piston rod of scale with a scale is nylon material in the present embodiment, sees Fig. 4.
In conjunction with Fig. 1, Fig. 2 and Fig. 3, step 1: two panels coil baffle is fixed on to the both ends of cylindrical tube with hot melt adhesive, it is fixed
When avoid screw position, place a period of time after smearing hot melt adhesive, wait hot melt adhesive to dry out and strengthen；
Step 2: enamel covered wire is uniformly wound in cylindrical tube, between two panels coil baffle, when coiling, one layer of every coiling
Coil coats one layer, after the completion of coiling with insulating tape, is uniformly coated on the outside of coil with insulating tape, the enamel-cover reserved
Copper wire is wrapped up with insulating gum cover, to form axially adjustable uniform magnetic field loading device, as shown in Figure 3.
Step 3: cylindrical tube rear end is screwed in after impedance tube measuring system on pipe, then impedance tube measuring system front tube position is adjusted,
Impedance tube measuring system front tube is connected with cylindrical tube front end, to form the sound with axially adjustable uniform magnetic field loading device
Measuring system is learned, as shown in Figure 1.
In the present embodiment, enamel covered wire circle is passed through after electric current forms one section of axial uniform magnetic field in cylindrical tube, and magnetic field is strong
Degree can quantitatively be controlled by the size of input current.
Axially adjustable uniform magnetic field loading device in the present embodiment is simulated defeated with COMSOLMultiphysics5.3a
When entering 15A electric current, internal magnetic field distribution situation, as a result as shown in Figure 5.
From figure 5 it can be seen that in axially adjustable uniform magnetic field loading device pipe near central regions larger range
Uniform magnetic field is generated, uniform magnetic field width is more than the half of pipe range, and magnetic field strength maximum is close to 0.11T in pipe inner axis.
Axially adjustable uniform magnetic field loading device in the present embodiment accesses DC power supply, 15A electric current is passed through, in cylinder
A test point is taken every 20mm on pipe axis, takes 13 points altogether, with Gauss instrument actual measurement each point magnetic field strength, is drawn in pipe
Magnetic field distribution curve is as shown in Figure 6 on axis.
From fig. 6 it can be seen that inner axial tube has a uniform magnetic field of nearly 100mm width range after being powered, it is whole and
Speech, the range of uniform magnetic field can satisfy requirement of experiment.
The present embodiment carries out lengthening transformation to impedance tube measuring system, is complete from the working principle angle analysis of impedance tube
It is feasible.
In the present embodiment, respectively by the same test specimen be packed into the impedance tube measuring system without magnetic field loading device in and tape spool
It is taken multiple measurements into the impedance tube measuring system of adjustable uniform magnetic field loading device.Wherein without the resistance of magnetic field loading device
The front and rear tube of anti-pipe measuring system is directly threadedly coupled；Impedance tube with axially adjustable uniform magnetic field loading device is surveyed
Amount system then increases an axially adjustable uniform magnetic field loading device, is placed between front and rear tube, and with screw thread by axis
It is connected to adjustable uniform magnetic field loading device with front tube, rear pipe.
When being packed into test specimen, for anti-leak-stopping sound, test specimen periphery is wound with unsintered tape, and spread vaseline.
The piston rod of test specimen scale with a scale as shown in Figure 4 is pushed into the improved axially adjustable uniform magnetic field of band
In the impedance tube measuring system of loading device.
Every time experiment need to according to the physical location of test specimen in impedance tube measuring system software kit Va-Lab adjusting parameter.
Test results are shown in figure 7, it can be seen from the figure that the impedance before improved impedance tube measuring system and transformation
Pipe measuring system measurement result consistency is very good, can satisfy requirement of experiment completely, and actual test shows to measure impedance tube
The transformation of system will not influence the measuring accuracy of equipment, i.e., the improved method proposed by the present invention to impedance tube measuring system is can
Capable.
In conjunction with the embodiments, the acoustic measurement system of the axially adjustable uniform magnetic field loading device of a kind of band proposed by the invention
System, can be under the premise of guaranteeing measurement accuracy, adjustable uniform magnetic field test environment needed for providing experiment.
Above-mentioned is the preferred embodiment of the present invention, cannot function as full scope of the invention, with one kind of the present invention
That is done on the basis of the acoustic measurement system with axially adjustable uniform magnetic field loading device any be significantly improved and simply become
It changes and belongs to patent coverage area of the invention.
Claims (8)
1. a kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band, which is characterized in that the acoustic measurement
System is made of impedance tube measuring system and axially adjustable uniform magnetic field loading device；Wherein axially adjustable uniform magnetic field adds
The front tube rear end and rear pipe front end for carrying the both ends and impedance tube measuring system set are connected, and are placed between front and rear tube, and
Axially concentric with front and rear tube, impedance tube measuring system sound source is installed on the front end of impedance tube measuring system front tube；It axially can
Uniform magnetic field loading device is adjusted to be made of cylindrical tube, coil baffle, enamel covered wire circle and DC power supply；Enamel covered wire circle is equal
Be wound in cylindrical tube evenly, when coiling at the beginning and end of all reserve enamel covered wire circle, for connecting direct current
Source；Cylindrical tube both ends are provided with coil baffle, and coil can generate uniform magnetic field after being passed through electric current in cylindrical tube, defeated by changing
The intensity adjustment magnetic field for entering electric current is strong and weak, sound insulation property variation of the test test specimen under the effect of axial uniform magnetic field；Cylinder simultaneously
Pipe is pushed into cylindrical tube as the test specimen pipe for putting test specimen to be measured, the piston rod of test specimen to be measured scale with a scale.
2. a kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band as described in claim 1, feature
It is, the long front and rear tube of impedance tube measuring system is all 800mm, and surface layout there are 6 sonic transducers on it, is used for
Acoustical signal is received, first sensor is located at the 5mm of front tube rear end, and second sensor is located at 8mm before first sensor, and third passes
Sensor is located at 22mm before second sensor, and after the 4th sensor is located at the 15mm of pipe front end, the 5th sensor is located at the 4th and passes
8mm behind sensor, the 6th sensor are located at 22mm behind the 5th sensor, guarantee that 6 sensors are generally aligned in the same plane and one
On straight line.
3. a kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band as described in claim 1, feature
It is, the graduated scale on piston rod can clearly represent the specific location that test specimen to be measured is located in cylindrical tube, i.e. graduated scale
Display how much, test specimen be just pushed into cylindrical tube how long distance；Graduated scale is installed on the surface of piston rod, guarantees scale direction and work
The end face of stopper rod is vertical, and when pushing piston rod, scale position will not change.
4. a kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band as described in claim 1, feature
It is, the cylindrical tube is made of aluminum；The cylinder bore and the inside radius r of impedance tube measuring system are consistent,
Outer diameter and the outer radius R of impedance tube measuring system are consistent, and length should be greater than 4r；Before cylindrical tube and impedance tube measuring system
The connection of pipe and rear pipe can be used screw thread or snap connection mode, need to guarantee that interface fits closely and axial direction is concentric after connection.
5. a kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band as described in claim 1, feature
It is, the enamel covered wire and DC power supply select the enameled wire and different capacity of different line footpaths according to required magnetic field size
DC power supply；The enamel covered wire circle is often coated around one layer with insulating tape in coiling, it is reserved to and DC power supply
One section of enameled wire of connection is wrapped up with insulating gum cover；The long 500mm of enamel covered wire circle reserved.
6. a kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band as described in claim 1, feature
It is, the coil baffle outer edge should be higher than that, around the enamel covered wire circle outermost made, the thickness of coil baffle guarantees
It is indeformable in enamel covered wire circle winding process and in experimentation；The coil baffle is made of nylon material.
7. a kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band as described in claim 1, feature
It is, the connection use between the coil baffle and cylindrical tube is threadedly coupled or the modes such as glue connection.
8. a kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band as described in claim 1, feature
It is, to guarantee during test specimen to be measured is pushed into cylindrical tube not by effects of air pressure, the piston rod band of the scale with a scale
There is deflector hole, the position of deflector hole is located at the front end face center that piston rod is contacted with test specimen and through entire piston rod；For
After guaranteeing test specimen push-in cylindrical tube to be measured, surface is vertical with plane wave, that is, when guaranteeing that test specimen to be measured is vertical, and guaranteeing push-in
It is smooth, the piston rod radius of scale with a scale is less than r greater than 0.8r, and piston rod front end is using indent design；Mark with a scale
The piston rod of ruler is made of nylon material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910649886.5A CN110501419A (en) | 2019-07-18 | 2019-07-18 | A kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910649886.5A CN110501419A (en) | 2019-07-18 | 2019-07-18 | A kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110501419A true CN110501419A (en) | 2019-11-26 |
Family
ID=68586043
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910649886.5A Pending CN110501419A (en) | 2019-07-18 | 2019-07-18 | A kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110501419A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113311068A (en) * | 2021-05-19 | 2021-08-27 | 江苏大学 | Axial magnetic field loading device with adjustable intensity |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101951537A (en) * | 2010-09-01 | 2011-01-19 | 谭和平 | Magnetorheological technology-based volume adjusting method and device |
| CN202562892U (en) * | 2012-03-29 | 2012-11-28 | 浙江吉利汽车研究院有限公司 | Acoustic absorption coefficient measurement system for standing wave tube method |
| CN103090881A (en) * | 2012-12-25 | 2013-05-08 | 陕西宝成航空仪表有限责任公司 | Galvanical solenoid for fiber optic gyroscope magnetic influence system |
| CN104681021A (en) * | 2015-02-11 | 2015-06-03 | 上海交通大学 | Magnetic-field-adjustable low-frequency sound insulation structure and sound insulation material |
| US20160077056A1 (en) * | 2014-09-11 | 2016-03-17 | National Tsing Hua University | Method of using dual-port measurement system to measure acoustic impedance |
| CN206020340U (en) * | 2016-08-23 | 2017-03-15 | 无锡吉兴汽车声学部件科技有限公司 | Impedance tube sound insulation measurement exemplar fixing device |
| CN206020341U (en) * | 2016-08-23 | 2017-03-15 | 无锡吉兴汽车声学部件科技有限公司 | Thin-film material impedance tube sound insulation test fixing device |
| CN106601223A (en) * | 2016-11-21 | 2017-04-26 | 浙江大学 | Device of realizing adjustable sound absorption performance based on magnetorheological effect |
| CN109671420A (en) * | 2018-11-27 | 2019-04-23 | 江苏大学 | A kind of film-type active acoustical Meta Materials coupled admittedly based on magnetic |
-
2019
- 2019-07-18 CN CN201910649886.5A patent/CN110501419A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101951537A (en) * | 2010-09-01 | 2011-01-19 | 谭和平 | Magnetorheological technology-based volume adjusting method and device |
| CN202562892U (en) * | 2012-03-29 | 2012-11-28 | 浙江吉利汽车研究院有限公司 | Acoustic absorption coefficient measurement system for standing wave tube method |
| CN103090881A (en) * | 2012-12-25 | 2013-05-08 | 陕西宝成航空仪表有限责任公司 | Galvanical solenoid for fiber optic gyroscope magnetic influence system |
| US20160077056A1 (en) * | 2014-09-11 | 2016-03-17 | National Tsing Hua University | Method of using dual-port measurement system to measure acoustic impedance |
| CN104681021A (en) * | 2015-02-11 | 2015-06-03 | 上海交通大学 | Magnetic-field-adjustable low-frequency sound insulation structure and sound insulation material |
| CN206020340U (en) * | 2016-08-23 | 2017-03-15 | 无锡吉兴汽车声学部件科技有限公司 | Impedance tube sound insulation measurement exemplar fixing device |
| CN206020341U (en) * | 2016-08-23 | 2017-03-15 | 无锡吉兴汽车声学部件科技有限公司 | Thin-film material impedance tube sound insulation test fixing device |
| CN106601223A (en) * | 2016-11-21 | 2017-04-26 | 浙江大学 | Device of realizing adjustable sound absorption performance based on magnetorheological effect |
| CN109671420A (en) * | 2018-11-27 | 2019-04-23 | 江苏大学 | A kind of film-type active acoustical Meta Materials coupled admittedly based on magnetic |
Non-Patent Citations (4)
| Title |
|---|
| MOHAMMAD J. MAHJOOB: "Analytical and experimental evaluation of magnetic field effect on sound transmission loss of MR-based smart multi-layered panels", 《APPLIED ACOUSTICS》 * |
| 中华人民共和国国家质量监督检验检疫总局中国国家标准化管理委员会: "声学 阻抗管中传声损失的测量 传递矩阵法", 《中华人民共和国国家标准化指导性技术文件》 * |
| 宋景等: "轴向均匀磁场线圈的设计", 《科技创新与应用》 * |
| 罗善德: "基于Biot理论的电磁流变液吸声特性研究", 《中国博士学位论文全文数据库 工程科技Ⅰ辑》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113311068A (en) * | 2021-05-19 | 2021-08-27 | 江苏大学 | Axial magnetic field loading device with adjustable intensity |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2013512414A5 (en) | ||
| CN104049229B (en) | Method for generating standard high frequency alternating magnetic field | |
| CN105467001A (en) | Integral MFL (Magnetic Flux Leakage) and eddy current array sensor for detecting copper-coated/aluminum-coated steel shaft type structure | |
| CN110501419A (en) | A kind of acoustic measurement system of the axially adjustable uniform magnetic field loading device of band | |
| BRPI0904893A2 (en) | method of conducting an electromagnetic induction investigation of a formation surrounding a perforated hole having a coating, method for conducting an electromagnetic induction investigation in a formation surrounding a perforated hole having a coating, system for performing electromagnetic induction measurements in a formation surrounding a drilled hole having a casing, and method for attenuation compensation in electromagnetic induction probe measurements | |
| CN108488301A (en) | A kind of MR damper in detectable damp channel magnetic field | |
| EP3215840B1 (en) | Method for evaluating the distribution, density and orientation of ferromagnetic, electrically conductive fibres in a composite material | |
| CN105180790B (en) | A kind of magnetostriction microdisplacement meter | |
| CN201917648U (en) | High pulse magnetic field measuring device through electromagnetic induction method | |
| CN201407989Y (en) | Electromagnetism detection device for oxide coating thickness of stainless steel tube | |
| US8710828B1 (en) | Actuators and moveable elements with position sensing | |
| CN107907587A (en) | A kind of underdamping state Pulsed Eddy Current Testing System | |
| CN207081405U (en) | A kind of high-precision magneto strictive sensor | |
| CN102364639A (en) | Plastic Rogowski coil mutual inductor and measuring method thereof | |
| CN106940168A (en) | A kind of electromagnetic wave absorbing coating thickness nondestructive thickness measuring instrument probe and thickness measuring method | |
| CN112731230A (en) | Device and method for testing initial permeability of imaginary part of ferrite at extremely weak magnetic pole low frequency | |
| CN107607893B (en) | A kind of design method of high flat degree medium-high magnetic field measuring coil | |
| CN207894462U (en) | A kind of wide-range compares electromagnetic flow transducer | |
| CN110609163A (en) | Non-invasive current and voltage metering device | |
| CN211117871U (en) | Flow measurement control integration electric valve | |
| CN204831414U (en) | Be applied to electromagnetic sensor of frequency conversion excitation technique | |
| RU175421U1 (en) | LOCAL SPEED SENSOR | |
| US3323364A (en) | Means for rejecting quadrature voltage signals in a flow meter | |
| CN114088969B (en) | Light gas big gun flight piece speed sensor based on electromagnetic induction | |
| CN111006804A (en) | Torque measuring device and measuring method thereof |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20191126 |