CN108956070A - One kind being based on magnetic rheology elastic body frequency conversion damper vibration damping experimental rig and its method - Google Patents
One kind being based on magnetic rheology elastic body frequency conversion damper vibration damping experimental rig and its method Download PDFInfo
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- CN108956070A CN108956070A CN201810719685.3A CN201810719685A CN108956070A CN 108956070 A CN108956070 A CN 108956070A CN 201810719685 A CN201810719685 A CN 201810719685A CN 108956070 A CN108956070 A CN 108956070A
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- G—PHYSICS
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- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
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Abstract
The invention discloses one kind to be based on magnetic rheology elastic body frequency conversion damper vibration damping experimental rig, including pedestal, the both upper ends thereof of the pedestal is respectively equipped with pillar, and the upper surface of pillar is provided with support, the upper end of the support is provided with support steel beam, the side of the support steel beam is fixedly installed steel cable, and the end of steel cable is wrapped on bull stick, the end of the bull stick is connected with transmission gear by shaft, the transmission gear connects adjusting knob by shaft, the middle lower surface of the support steel beam is equipped with mass block, and acceleration transducer is installed in the middle part of mass block, connector is equipped at the middle part corresponding mass block of the pedestal, and the top of connector is equipped with vibration excitor.The present invention, which carries out frequency identification as the foundation of magnetic rheology elastic body frequency conversion damper stiffness control strategy to the response signal of acquisition in such a way that HHT and MRDT are combined, can effectively verify the effect of damping based on magnetic rheology elastic body frequency conversion damper.
Description
Technical field
The present invention relates to technical field of structural engineering, more particularly to one kind to be based on magnetic rheology elastic body frequency conversion damper vibration damping
Experimental rig and its method.
Background technique
It is to utilize magnetic current as main rigidity element by magnetic rheology elastic body based on magnetic rheology elastic body frequency conversion damper
The modulus of shearing for becoming elastomer can realize that frequency can change with main structure frequency and be changed with the intelligent controllable characteristic of externally-applied magnetic field
Novel damping device, the control of magnetic field size can realize by changing the electric current of damper coil.In recent years, it is based on
The result of design of magnetic rheology elastic body frequency conversion damper emerges one after another, and has been obtained on effectiveness in vibration suppression theory level sufficiently
Research, but to be applied in practical structures and must be verified by reliably testing.
The pilot system for carrying out damper vibration damping performance test at present is limited to damper mostly and acts on the fixed master of frequency
In structure, the parameter that damper is adjusted according to the difference of load driving frequency carries out vibration damping, to verify the vibration damping of damper
Effect, such experimental rig are not suitable for frequency conversion damper vibration damping performance test.Frequency conversion damper need first to main structure into
Row system identification makes feedback by controller according to the result of system identification, carries out intelligent adjusting to the frequency of damper.?
Test device systematic identification aspect, using traditional frequency domain method, frequency domain method needs to obtain system the overwhelming majority at present
Pumping signal and response signal excessively rely on the quality of surveyed frequency response function, still, according to the limitation and reality of experimental condition
Structure is often difficult accurately to measure desired excitation signal, and relies on traditional frequency domain method and solve obtained system parameter
Often precision is not high, and there are biggish errors compared with the true mode of practical structures, meanwhile, the efficiency of system identification is lower,
This brings bigger limitation in real-time vibration control.
Summary of the invention
Technical problems based on background technology, the invention proposes one kind to be based on magnetic rheology elastic body frequency conversion damper
Damping test devices and methods therefor.
It is proposed by the present invention a kind of based on magnetic rheology elastic body frequency conversion damper vibration damping experimental rig, including pedestal, it is described
The both upper ends thereof of pedestal is respectively equipped with pillar, and the upper surface of pillar is provided with support, and the upper end of the support is provided with support
Girder steel, the side of the support steel beam is fixedly installed steel cable, and the end of steel cable is wrapped on bull stick, the end of the bull stick
Transmission gear is connected with by shaft, and the transmission gear connects adjusting knob by shaft, under the middle part of the support steel beam
Surface is equipped with mass block, and acceleration transducer is equipped in the middle part of mass block, sets at the middle part corresponding mass block of the pedestal
There is connector, and the top of connector is equipped with vibration excitor, the middle part upper surface of the support steel beam is equipped with magnetic rheology elastic body
Frequency conversion damper, the output end of the magnetic rheology elastic body frequency conversion damper and the input terminal of charge amplifier connect, and charge
The output end of amplifier and the input terminal of controller connect, and the output end of the controller and the input terminal of signal source connect, and
The output end of signal source and the input terminal of power amplifier connect, the output end of the power amplifier and the input terminal of vibration excitor
The input terminal of connection, the magnetic rheology elastic body frequency conversion damper is connected by the output end of conducting wire and DC power supply, and direct current
The input terminal of power supply is electrically connected by the output end of conducting wire and controller, and the controller is by signal receiving/transmission device and calculates
The connection of machine signal.
Preferably, bolt is all made of between the mass block and support steel beam to be fixedly connected.
Preferably, the quantity of the mass block is at least one, and is bolted to connection between mass block.
One kind being based on magnetic rheology elastic body frequency conversion damper vibration damping test method, the specific steps are as follows:
Step 1: adjusting knob makes drive gears turn bar bull stick, and steel cable tightening is made to apply one to support steel beam both ends
Fixed axial constraint power, while controller control DC power supply carries out the electric current of magnetic rheology elastic body frequency conversion damper coil
Initialization；
Step 2: white-noise excitation signal is issued using controller control signal source, through power amplifier and vibration excitor pair
Main structure applies white-noise excitation；
Step 3: the measuring point response signal X that acceleration transducer is acquired1(t) it is transferred in controller, utilizes HHT+
The frequency identification of MRDT progress main structure；
Step 4: direct current control switch is opened using controller, according in magnetic rheology elastic body frequency conversion damper winding
Relationship between size of current and the natural frequency of vibration, using stiffness reliability strategy, the size for controlling direct current makes the parameter of damper
It is optimal, it is X that accelerated degree sensor, which measures response signal at this time,2(t)；
Step 5: adjusting knob or the quantity for changing mass block make the frequency of main structure change, and repeat step 2
To step 4, each group X is compared1(t) and X2(t) size of amplitude, and then verify the vibration damping of magnetic rheology elastic body frequency conversion damper
Effect.
It is in the present invention the utility model has the advantages that the present invention using improved Random Decrement Technique (MRDT) to main structure carry out frequency
Identification, MRDT simultaneously intercept signal using positive negative threshold value, increase average time, to improve free vibration response letter
Number quality, in main structure apply restraining force and change main structure quality with realize frequency adjust effect, apply restraining force
Strategy be to adjust the axial tension applied at girder steel both ends, support steel beam both ends are separately connected steel cable, the other end just restricted with
The bull stick connection of centre perforation, the rotation of bull stick are controlled by adjusting knob by transmission gear, are combined using HHT and MRDT
Mode frequency identification is carried out to the response signal of acquisition, as magnetic rheology elastic body frequency conversion damper stiffness control strategy according to
According to can effectively verify the effect of damping based on magnetic rheology elastic body frequency conversion damper.
Detailed description of the invention
Attached drawing is used to provide further understanding of the present invention, and constitutes part of specification, the implementation with invention
Example is used to explain the present invention together, is not construed as limiting the invention.In the accompanying drawings:
Fig. 1 is the schematic diagram of experimental rig of the present invention；
Fig. 2 is that beam-ends of the present invention applies restraining force structural schematic diagram；
Fig. 3 is the present invention just rope tension adjustment structure schematic diagram；
Fig. 4 is present system control principle flow chart.
In figure: just rope, 7 magnetic rheology elastic body frequency conversions damp for 1 pedestal, 2 pillars, 3 support steel beams, 4 connectors, 5 supports, 6
Device, 8 vibration excitors, 9 charge amplifiers, 10 controllers, 11 computers, 12 signal sources, 13 power amplifiers, 14 DC power supplies, 15
Acceleration transducer, 16 adjusting knobs, 17 bull sticks, 18 transmission gears, 19 mass blocks.
Specific embodiment
Combined with specific embodiments below the present invention is made further to explain.
Embodiment 1
One kind being based on magnetic rheology elastic body frequency conversion damper vibration damping experimental rig, including pedestal 1, the top of the pedestal 1
Both ends are respectively equipped with pillar 2, and the upper surface of pillar 2 is provided with support 5, and the upper end of the support 5 is provided with support steel beam 3,
The side of the support steel beam 3 is fixedly installed steel cable 6, and the end of steel cable 6 is wrapped on bull stick 17, the end of the bull stick 17
End is connected with transmission gear 18 by shaft, and the transmission gear 18 connects adjusting knob 16, the support steel beam 3 by shaft
Middle lower surface be equipped with mass block 19, and the middle part of mass block 19 is equipped with acceleration transducer 15, the middle part of the pedestal 1
Connector 4 is equipped at corresponding mass block 19, and the top of connector 4 is equipped with vibration excitor 8, on the middle part of the support steel beam 3
Surface is equipped with magnetic rheology elastic body frequency conversion damper 7, and the output end and charge of the magnetic rheology elastic body frequency conversion damper 7 amplify
The input terminal of device 9 connects, and the output end of charge amplifier 9 is connect with the input terminal of controller 10, the controller 10 it is defeated
Outlet is connect with the input terminal of signal source 12, and the output end of signal source 12 is connect with the input terminal of power amplifier 13, described
The output end of power amplifier 13 is connect with the input terminal of vibration excitor 8, the input of the magnetic rheology elastic body frequency conversion damper 7
End is connect by conducting wire with the output end of DC power supply 14, and the input terminal of DC power supply 14 passes through the defeated of conducting wire and controller 10
Outlet is electrically connected, and the controller 10 is connect by signal receiving/transmission device with 11 signal of computer.
It is all made of bolt between the mass block 19 and support steel beam 3 to be fixedly connected, the quantity of the mass block 19 is at least
It is one, and is bolted to connection between mass block 19.
One kind being based on magnetic rheology elastic body frequency conversion damper vibration damping test method, the specific steps are as follows:
Step 1: adjusting knob 16 makes transmission gear 18 drive bull stick bull stick 17, makes the tightening of steel cable 6 to 3 liang of support steel beam
End applies certain axial constraint power, while controller 10 controls DC power supply 14 in magnetic rheology elastic body frequency conversion damper 7
The electric current of coil is initialized；
Step 2: controlling signal source 12 using controller 10 and issue white-noise excitation signal, through power amplifier 13 and swashs
The device 8 that shakes applies white-noise excitation to main structure；
Step 3: the measuring point response signal X that acceleration transducer 15 is acquired1(t) it is transferred in controller 10, utilizes
The frequency identification of HHT+MRDT progress main structure；
Step 4: direct current control switch is opened using controller 10, according to 7 coil of magnetic rheology elastic body frequency conversion damper
Relationship between middle size of current and the natural frequency of vibration, using stiffness reliability strategy, the size for controlling direct current makes the ginseng of damper
Number is optimal, and it is X that accelerated degree sensor 15, which measures response signal at this time,2(t)；
Step 5: adjusting knob 16 or the quantity for changing mass block 19 make the frequency of main structure change, and repeat to walk
Rapid two, to step 4, compare each group X1(t) and X2(t) size of amplitude, and then verify magnetic rheology elastic body frequency conversion damper
Effect of damping.
The rotation of bull stick 17 is controlled by transmission gear 18 by adjusting knob 16, when bull stick 17 turns toward just rope direction is tensed
When dynamic, the axial force for being applied to 3 both ends of support steel beam increases, magnetic rheology elastic body frequency conversion damper 7 be fixed on support steel beam 3 across
Middle top, mass block 19 are applied among support steel beam 3, are all made of between different quality block, between mass block and support steel beam 3
Bolt is fixedly connected, and so that support steel beam 3 and mass block 19 is become the entirety without relative motion, in 3 both ends institute of support steel beam
Apply axial force it is constant when, 19 quantity of mass block increases, and the fundamental frequency of main structure reduces, on the contrary then increase, the mandril pair of vibration excitor 8
The center of quasi- mass block 19 applies white-noise excitation to girder steel span centre, and acceleration transducer 15 is main by the support steel beam 3 of acquisition
Structure acceleration response signal is transferred in controller 10 by charge amplifier 9, control algolithm used by controller 10 with
And control switch can use computer 11 and be operated, controller 10 can control signal source 12 and issue white-noise excitation signal
White-noise excitation is applied to main structure using vibration excitor 8 after power amplifier 13, also can control DC power supply 14 makes magnetic current
Become the controlled current flow in the coil in elastomer frequency conversion damper 7, realizes rigidity tunning effect in main structure.
The present invention carries out main structure using Hilbert-Huang transform (HHT) and improved Random Decrement Technique (MRDT)
Frequency identification, controller use MRDT controller, are intercepted simultaneously to signal using positive negative threshold value, increase average time,
To improve the quality of free vibration response signal, frequency identification process are as follows: firstly, for the acceleration responsive signal to measuring point
Fourier transform is carried out, fourier spectra is obtained, by the approximate range of former order frequencies in estimation fourier spectra, uses bandpass filtering
Response signal is handled, former rank modal responses of empirical mode decomposition (EMD) available model structure are then utilized,
Each rank modal response is handled using MRDT, the free damping response of available corresponding mode, finally, being rung to free damping
Induction signal carries out the instantaneous frequency that Hilbert transformation acquires main structure, need to only identify to the fundamental frequency of main structure, measuring point cloth
It sets at the maximum displacement of girder steel, response signal is acquired by acceleration transducer.
The foregoing is only a preferred embodiment of the present invention, but scope of protection of the present invention is not limited thereto,
Anyone skilled in the art in the technical scope disclosed by the present invention, according to the technique and scheme of the present invention and its
Inventive concept is subject to equivalent substitution or change, should be covered by the protection scope of the present invention.
Claims (3)
1. one kind is based on magnetic rheology elastic body frequency conversion damper vibration damping experimental rig, which is characterized in that including pedestal, the pedestal
Both upper ends thereof be respectively equipped with pillar, and the upper surface of pillar is provided with support, and the upper end of the support is provided with support steel beam,
The side of the support steel beam is fixedly installed steel cable, and the end of steel cable is wrapped on bull stick, and the end of the bull stick passes through
Shaft is connected with transmission gear, and the transmission gear connects adjusting knob, the middle lower surface of the support steel beam by shaft
Equipped with mass block, and acceleration transducer is installed in the middle part of mass block, the company of being equipped at the middle part corresponding mass block of the pedestal
Fitting, and the top of connector is equipped with vibration excitor, the middle part upper surface of the support steel beam is equipped with magnetic rheology elastic body frequency conversion
Damper, the output end of the magnetic rheology elastic body frequency conversion damper and the input terminal of charge amplifier connect, and charge amplifies
The output end of device and the input terminal of controller connect, and the output end of the controller and the input terminal of signal source connect, and signal
The output end in source and the input terminal of power amplifier connect, and the output end of the power amplifier and the input terminal of vibration excitor connect
It connects, the input terminal of the magnetic rheology elastic body frequency conversion damper is connected by the output end of conducting wire and DC power supply, and direct current
The input terminal in source is electrically connected by the output end of conducting wire and controller, and the controller passes through signal receiving/transmission device and computer
Signal connection.
2. according to claim 1 a kind of based on magnetic rheology elastic body frequency conversion damper vibration damping experimental rig, feature exists
In being all made of bolt between the mass block and support steel beam and be fixedly connected.
3. according to claim 1 a kind of based on magnetic rheology elastic body frequency conversion damper vibration damping experimental rig, feature exists
In the quantity of the mass block is at least one, and is bolted to connection between mass block.
Described one kind is based on magnetic rheology elastic body frequency conversion damper vibration damping test method, the specific steps are as follows:
Step 1: adjusting knob makes drive gears turn bar bull stick, applies steel cable tightening centainly to support steel beam both ends
Axial constraint power, while controller control DC power supply carries out initially the electric current of magnetic rheology elastic body frequency conversion damper coil
Change；
Step 2: white-noise excitation signal is issued using controller control signal source, through power amplifier and vibration excitor to main knot
Structure applies white-noise excitation；
Step 3: the measuring point response signal X that acceleration transducer is acquired1(t) be transferred in controller, using HHT+MRDT into
The frequency identification of row main structure；
Step 4: direct current control switch is opened using controller, according to electric current in 7 coil of magnetic rheology elastic body frequency conversion damper
Relationship between size and the natural frequency of vibration, using stiffness reliability strategy, the size for controlling direct current reaches the parameter of damper
Optimal, it is X that accelerated degree sensor, which measures response signal at this time,2(t)；
Step 5: adjusting knob or the quantity for changing mass block make the frequency of main structure change, and repeat step 2 to step
Rapid four, compare each group X1(t) and X2(t) size of amplitude, and then verify the vibration damping effect of magnetic rheology elastic body frequency conversion damper
It answers.
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| CN201810719685.3A CN108956070B (en) | 2018-07-03 | 2018-07-03 | variable frequency damper vibration reduction test device based on magnetorheological elastomer and method thereof |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112056092A (en) * | 2020-08-10 | 2020-12-11 | 华南农业大学 | Variable-frequency variable-amplitude excitation type vibration harvesting device and amplitude modulation and use method thereof |
| CN113139270A (en) * | 2020-01-20 | 2021-07-20 | 莆田学院 | Magneto-rheological vibration reduction system dynamics modeling device and method |
| CN113447247A (en) * | 2020-03-25 | 2021-09-28 | 广州汽车集团股份有限公司 | Shock absorber parameter testing device, shock absorber parameter obtaining method and device |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1869972A (en) * | 2006-06-15 | 2006-11-29 | 沈阳建筑大学 | Structural response analysing method of improving Hibert-Huang transform |
| CN101968398A (en) * | 2010-10-15 | 2011-02-09 | 合肥工业大学 | Dynamic property testing platform for movable mass simply-supported beam |
| CN104713721A (en) * | 2015-04-10 | 2015-06-17 | 株洲时代新材料科技股份有限公司 | Dynamic performance test platform of vibration isolator system and test method thereof |
| CN107121274A (en) * | 2017-06-09 | 2017-09-01 | 武汉理工大学 | One kind is based on magnetic rheology elastic body frequency conversion damper vibration damping experimental rig and system |
| CN206601223U (en) * | 2017-03-31 | 2017-10-31 | 华东交通大学 | A kind of MR damper vibration performance test system |
| CN107421729A (en) * | 2017-08-11 | 2017-12-01 | 南京理工大学 | A kind of MR elastomer vibration isolator dynamic performance testing system |
-
2018
- 2018-07-03 CN CN201810719685.3A patent/CN108956070B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1869972A (en) * | 2006-06-15 | 2006-11-29 | 沈阳建筑大学 | Structural response analysing method of improving Hibert-Huang transform |
| CN101968398A (en) * | 2010-10-15 | 2011-02-09 | 合肥工业大学 | Dynamic property testing platform for movable mass simply-supported beam |
| CN104713721A (en) * | 2015-04-10 | 2015-06-17 | 株洲时代新材料科技股份有限公司 | Dynamic performance test platform of vibration isolator system and test method thereof |
| CN206601223U (en) * | 2017-03-31 | 2017-10-31 | 华东交通大学 | A kind of MR damper vibration performance test system |
| CN107121274A (en) * | 2017-06-09 | 2017-09-01 | 武汉理工大学 | One kind is based on magnetic rheology elastic body frequency conversion damper vibration damping experimental rig and system |
| CN107421729A (en) * | 2017-08-11 | 2017-12-01 | 南京理工大学 | A kind of MR elastomer vibration isolator dynamic performance testing system |
Non-Patent Citations (2)
| Title |
|---|
| 施卫星 等: ""自调频调谐质量阻尼器及其减振性能试验"", 《同济大学学报（自然科学版）》 * |
| 涂建维 等: ""基于磁流变弹性体的调频TMD减振装置"", 《地震工程与工程振动》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113139270A (en) * | 2020-01-20 | 2021-07-20 | 莆田学院 | Magneto-rheological vibration reduction system dynamics modeling device and method |
| CN113139270B (en) * | 2020-01-20 | 2022-08-26 | 莆田学院 | Magneto-rheological vibration reduction system dynamics modeling device and method |
| CN113447247A (en) * | 2020-03-25 | 2021-09-28 | 广州汽车集团股份有限公司 | Shock absorber parameter testing device, shock absorber parameter obtaining method and device |
| CN112056092A (en) * | 2020-08-10 | 2020-12-11 | 华南农业大学 | Variable-frequency variable-amplitude excitation type vibration harvesting device and amplitude modulation and use method thereof |
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