CN107271301A - A kind of multiple Young's modulus measuring method of viscoelastic material extracted based on direct wave - Google Patents
A kind of multiple Young's modulus measuring method of viscoelastic material extracted based on direct wave Download PDFInfo
- Publication number
- CN107271301A CN107271301A CN201710413324.1A CN201710413324A CN107271301A CN 107271301 A CN107271301 A CN 107271301A CN 201710413324 A CN201710413324 A CN 201710413324A CN 107271301 A CN107271301 A CN 107271301A
- Authority
- CN
- China
- Prior art keywords
- mrow
- msub
- omega
- sample
- signal
- 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.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0001—Type of application of the stress
- G01N2203/001—Impulsive
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
- G01N2203/0075—Strain-stress relations or elastic constants
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/0202—Control of the test
- G01N2203/021—Treatment of the signal; Calibration
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/0202—Control of the test
- G01N2203/0212—Theories, calculations
- G01N2203/0216—Finite elements
Abstract
The present invention proposes a kind of multiple Young's modulus measuring method of viscoelastic material extracted based on direct wave, the impulse response function H (ω) of measuring system is obtained first, is secondly obtained according to H (ω) when the Fourier transformation result for requiring vibrator exciting end pumping signal is H3When (ω), signal generator needs the signal S (t) exported, then time-domain signal S (t) is sent to vibrator by signal generator, the extensional vibration signal of measurement sample fixing end and sample free end, the storage modulus E ' and fissipation factor tan (δ) of material are calculated finally according to formula respectively.The property calculation that the present invention is propagated by direct wave in thin rod obtains multiple Young's modulus, explicit physical meaning and easy to operate, pass through the extraction to direct wave in the thin rod of viscoplasticity, avoid the influence of two ends back wave, its parameter direct measurement frequency range is wider, sample resonant frequency is not limited to, and measurement result is continuous in wide frequency range.
Description
Technical field
It is specially a kind of based on gluing that direct wave is extracted the present invention relates to viscoelastic material dynamic mechanics parameter fields of measurement
Direct measuring method in the continuous wide frequency range of the multiple Young's modulus of elastomeric material.
Background technology
In viscoelastic material dynamic mechanics parameter fields of measurement, the conventional measurement skill of the multiple Young's modulus of current viscoelastic material
Art mainly forces non-resonance method, forced resonance method, wave velocity method and inverse finite element method.
Wherein, force non-resonance method to encourage sample using sinusoidal stress, it is made forced vibration and produce corresponding deformation,
The multiple Young's modulus of material is obtained by the measurement of the phase difference to being applied between the stress and strain on sample, its is typical
Direct measurement frequency range is 0.01~100Hz, and the parameter of high-frequency range need to be calculated by time temperature equivalence principle to be obtained.Its advantage
It is that low frequency measurement precision is high, shortcoming is to expand obtained high-frequency data indirectly measurement result by time temperature equivalence, and error can not
Estimate.
Forced resonance method mainly uses a broadband signal to enter row energization to rod-like samples, to the freedom of extensional vibration sample
The extensional vibration response of end and fixing end is measured, so that the Oscillation Amplitude ratio curve of its free end and fixing end is obtained,
Amplitude Ration obtains the multiple Young's modulus at resonant frequency when then by resonating.Its advantage is that signal to noise ratio is high, has the disadvantage measurement knot
Fruit is confined to discrete resonant frequency point.
Wave velocity method mainly uses simple signal to carry out longitudinal pumping to rod-like samples, using two laser vibration measurers to sample
The oscillation crosswise of two sides is measured respectively at product position, can be eliminated the influence of flexural vibrations after measured result superposition, be obtained
To the oscillation crosswise triggered because there is Poisson's ratio by extensional vibration, the oscillation crosswise to sample another position is measured,
Then the multiple Young's modulus of sample is obtained by the time delay and decay calculation of 2 vibratory responses.Its advantage is that principle is simple, is lacked
Point is that oscillation crosswise is difficult measurement, and due to the influence of reflected signal in sample, and measurement frequency is difficult too low, and the method essence
Upper is single-frequency measuring method.
Inverse finite element method is mainly by carrying out finite element modeling to viscoelastic material, and input parameter is the springform of material
Amount, is contrasted by the material surface vibratory response and experimental measurements that obtain FEM calculation, continues to optimize input parameter
So that both deviations meet error condition, so as to obtain the multiple Young's modulus of material, the method advantage is not limited to be surveyed parameter
At the resonant frequency of sample, shortcoming is under certain conditions, Inversion Calculation model can not restrain.
The content of the invention
Due in existing e measurement technology, forcing the direct measurement frequency range of non-resonance method relatively low, the survey of forced resonance method
Amount frequency be limited at discrete Frequency point, the measurement frequency scope of wave velocity method is higher, inverse finite element method exist model without
The convergent situation of method.The present invention proposes a kind of measuring method for the multiple Young's modulus of viscoelastic material extracted based on direct wave,
The property calculation propagated by direct wave in thin rod obtains multiple Young's modulus, explicit physical meaning and easy to operate.By right
The extraction of direct wave in the thin rod of viscoplasticity, it is to avoid the influence of two ends back waves, its parameter direct measurement frequency range is wider, no
It is limited to sample resonant frequency, and measurement result is continuous in wide frequency range.
To achieve the above object, the present invention proposes a kind of multiple Young's modulus measurement of viscoelastic material extracted based on direct wave
Method, using including measuring instruments such as vibrator, laser vibration measurer, power amplifier, signal generation apparatus, data acquisition devices
Device, signal generator provides excitation by power amplifier for vibrator, by laser vibration measurer to vibrator exciting end and sample
The vibration velocity signal of product free end measures and passes to data acquisition device.Specific measuring process is as follows：
Step 1：The impulse response function H (ω) of measuring system is obtained by procedure below：
Signal generator sends wideband pulse signal to vibrator, and the Fourier transformation result of the wideband pulse signal is
H1Extensional vibration is made at (ω), the exciting end of vibrator, and the extensional vibration signal at measurement exciting end obtains Fu of extensional vibration signal
In leaf transformation result be H2(ω)；The impulse response function for obtaining measuring system is H (ω)=H2(ω)/H1(ω)；
Step 2：The impulse response function H (ω) of the measuring system obtained according to step 1, obtains that vibrator exciting ought be required
The Fourier transformation result for holding pumping signal is H3When (ω), signal generator needs the Fourier transformation result of the signal exported
For H0(ω)=H3(ω)/H (ω), to H0(ω) carries out inversefouriertransform and obtains time-domain signal S (t)；
Step 3：Sample will be measured and be processed as the club shaped structure that cross section is rectangle；Measure sample one end free, the other end
The vertical exciting end for sticking in vibrator；Time-domain signal S (t) is sent to vibrator by signal generator, and sample is measured respectively and is consolidated
Fixed end and the extensional vibration signal of sample free end；The Fourier transformation result for obtaining sample fixing end extensional vibration signal is Vg
(ω), the Fourier transformation result of sample free end extensional vibration signal is Vz(ω)；
Step 4：The Fourier transformation result for obtaining direct wave at sample fixing end is Vg(ω), sample free end goes directly
The Fourier transformation result of ripple is VT(ω)：
Select amplitude in above-mentioned result of calculation straight as sample free end less than the solution of the through wave amplitude of sample fixing end
Up to the Fourier transformation result V of rippleT(ω)；
Step 5：At the sample fixing end obtained according to step 4 and sample free end direct wave Fourier transformation knot
Really, calculate and obtain the longitudinal wave velocity c (ω) and attenuation coefficient α (ω) of rod-like samples and be：
Wherein l is rod-like samples length, and ω is frequency,Represent the phase of direct wave at sample fixing end；
The phase of sample free end direct wave is represented, unwrap is phase unwrapping around function；
Step 6：The longitudinal wave velocity c (ω) and attenuation coefficient α (ω) of the rod-like samples obtained according to step 5, are calculated
To the storage modulus E ' and fissipation factor tan (δ) of material：
Wherein ρ is density of material, and δ represents the phase of multiple Young's modulus.
Beneficial effect
The present invention has the following effects that：
1st, the influence of sample rod two ends reflected signal is eliminated, the direct wave in extensional vibration sample rod is extracted.
2nd, it is used for the calculating of multiple Young's modulus due to extracting direct wave, overcomes the shadow of back wave in traditional wave velocity method
Ring, widened the test frequency scope of multiple Young's modulus.
3rd, the measurement result of multiple Young's modulus is not limited at resonant frequency, can be measured and be obtained gluing in continuous wide frequency range
The multiple Young's modulus of elastomeric material.
The additional aspect and advantage of the present invention will be set forth in part in the description, and will partly become from the following description
Obtain substantially, or recognized by the practice of the present invention.
Brief description of the drawings
The above-mentioned and/or additional aspect and advantage of the present invention will become from description of the accompanying drawings below to embodiment is combined
Substantially and be readily appreciated that, wherein：
Fig. 1：Experimental provision schematic diagram used of the invention；
Fig. 2：The measurement result of elastomeric material storage modulus and fissipation factor.
Embodiment
Embodiments of the invention are described below in detail, the embodiment is exemplary, it is intended to for explaining the present invention, and
It is not considered as limiting the invention.
The measurement of multiple Young's modulus has been carried out in this example to viscoelastic rubber material：
The measurement apparatus used in this example include laser vibration measurer, vibrator, power amplifier, signal generation apparatus and
Data acquisition device.Signal generator provides excitation by power amplifier for vibrator, and vibrator is swashed by laser vibration measurer
Shake end and the vibration velocity signal of sample free end measures and passes to data acquisition device.
Using said apparatus, the multiple Young's modulus measuring method of viscoelastic material is comprised the steps of：
Step 1：The impulse response function H (ω) of measuring system is obtained by procedure below：
Signal generator sends wideband pulse signal to vibrator, and the Fourier transformation result of the wideband pulse signal is
H1Extensional vibration is made at (ω), the exciting end of vibrator, and the extensional vibration rate signal at exciting end is measured using laser vibration measurer, is obtained
Fourier transformation result to extensional vibration rate signal is H2(ω)；The impulse response function for obtaining measuring system is H (ω)
=H2(ω)/H1(ω)；
Step 2：The impulse response function H (ω) of the measuring system obtained according to step 1, obtains that vibrator exciting ought be required
The Fourier transformation result for holding pumping signal is H3When (ω), signal generator needs the Fourier transformation result of the signal exported
For H0(ω)=H3(ω)/H (ω), to H0(ω) carries out inversefouriertransform and obtains time-domain signal S (t)；By resulting time domain
Signal S (t) is sent to vibrator by signal generator, you can generate the preferable wideband pulse signal of waveform at vibrator exciting end
For subsequently measuring；
Step 3：Sample will be measured and be processed as the club shaped structure that cross section is 5mm × 5mm rectangles, length is 150mm；Measurement
Sample one end is free, and the other end sticks in the exciting end of vibrator vertically；Time-domain signal S (t) is sent to sharp by signal generator
Shaken device, and the extensional vibration rate signal of sample fixing end and sample free end is measured respectively；Obtain sample fixing end extensional vibration
The Fourier transformation result of rate signal is Vg(ω), the Fourier transformation result of sample free end extensional vibration rate signal is
Vz(ω)；
Step 4：The Fourier transformation result for obtaining direct wave at sample fixing end is Vg(ω), sample free end goes directly
The Fourier transformation result of ripple is VT(ω)：
Because direct wave is constantly decayed in the sample, select amplitude in above-mentioned result of calculation straight less than sample fixing end
Up to wave amplitude solution as sample free end direct wave Fourier transformation result VT(ω)；
Step 5：At the sample fixing end obtained according to step 4 and sample free end direct wave Fourier transformation knot
Really, calculate and obtain the longitudinal wave velocity c (ω) and attenuation coefficient α (ω) of rod-like samples and be：
Wherein l is rod-like samples length, and ω is frequency,Represent the phase of direct wave at sample fixing end；
Represent sample free end direct wave phase, unwrap be matlab softwares in phase unwrapping around function, to eliminate ratio
Larger phase hit；
Step 6：The longitudinal wave velocity c (ω) and attenuation coefficient α (ω) of the rod-like samples obtained according to step 5, are calculated
To the storage modulus E ' and fissipation factor tan (δ) of material：
Wherein ρ is density of material, and δ represents the phase of multiple Young's modulus.
In this example, Butterworth broadbands short pulse is generated on vibrator as pumping signal, then according to survey
Amount principle is measured, and is contrasted with viscoelastic instrument test result and traditional wave velocity method test result, measurement result
As shown in Fig. 2 being the storage modulus and fissipation factor of the elastomeric material measured in example, it can be seen that this method measurement gained
As a result it is coincide with viscoelastic instrument measurement result preferable, demonstrates the validity of this method；Compared to traditional wave velocity method, this method is low
Frequency measurement is more accurate, that is, has widened the multiple Young's modulus of viscoelastic material low-frequency range measured directly.
Although embodiments of the invention have been shown and described above, it is to be understood that above-described embodiment is example
Property, it is impossible to limitation of the present invention is interpreted as, one of ordinary skill in the art is not departing from the principle and objective of the present invention
In the case of above-described embodiment can be changed within the scope of the invention, change, replace and modification.
Claims (1)
1. a kind of multiple Young's modulus measuring method of viscoelastic material extracted based on direct wave, it is characterised in that：Including following step
Suddenly：
Step 1：The impulse response function H (ω) of measuring system is obtained by procedure below：
Signal generator sends wideband pulse signal to vibrator, and the Fourier transformation result of the wideband pulse signal is H1
Make in extensional vibration, the extensional vibration signal at measurement exciting end, Fu for obtaining extensional vibration signal at (ω), the exciting end of vibrator
Leaf transformation result is H2(ω)；The impulse response function for obtaining measuring system is H (ω)=H2(ω)/H1(ω)；
Step 2：The impulse response function H (ω) of the measuring system obtained according to step 1, obtains to require that vibrator exciting end is swashed
The Fourier transformation result for encouraging signal is H3When (ω), signal generator needs the Fourier transformation result of the signal exported to be H0
(ω)=H3(ω)/H (ω), to H0(ω) carries out inversefouriertransform and obtains time-domain signal S (t)；
Step 3：Sample will be measured and be processed as the club shaped structure that cross section is rectangle；Measure sample one end free, the other end is vertical
Stick in the exciting end of vibrator；Time-domain signal S (t) is sent to vibrator by signal generator, and sample fixing end is measured respectively
With the extensional vibration signal of sample free end；The Fourier transformation result for obtaining sample fixing end extensional vibration signal is Vg
(ω), the Fourier transformation result of sample free end extensional vibration signal is Vz(ω)；
Step 4：The Fourier transformation result for obtaining direct wave at sample fixing end is Vg(ω), sample free end direct wave
Fourier transformation result is VT(ω)：
<mrow>
<msub>
<mi>V</mi>
<mi>T</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<msub>
<mi>V</mi>
<mi>g</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
<mo>&CenterDot;</mo>
<mo>&lsqb;</mo>
<mfrac>
<mrow>
<msub>
<mi>V</mi>
<mi>g</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
</mrow>
<mrow>
<msub>
<mi>V</mi>
<mi>z</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
</mrow>
</mfrac>
<mo>&PlusMinus;</mo>
<msqrt>
<mrow>
<msup>
<mrow>
<mo>(</mo>
<mfrac>
<mrow>
<msub>
<mi>V</mi>
<mi>g</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
</mrow>
<mrow>
<msub>
<mi>V</mi>
<mi>z</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
</mrow>
</mfrac>
<mo>)</mo>
</mrow>
<mn>2</mn>
</msup>
<mo>-</mo>
<mn>1</mn>
</mrow>
</msqrt>
<mo>&rsqb;</mo>
</mrow>
Amplitude in above-mentioned result of calculation is selected to be less than the solution of the through wave amplitude of sample fixing end as sample free end direct wave
Fourier transformation result VT(ω)；
Step 5：At the sample fixing end obtained according to step 4 and sample free end direct wave Fourier transformation result,
Calculate and obtain the longitudinal wave velocity c (ω) and attenuation coefficient α (ω) of rod-like samples and be：
<mrow>
<mi>&alpha;</mi>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<mfrac>
<mrow>
<mi>l</mi>
<mi>n</mi>
<mrow>
<mo>(</mo>
<mo>|</mo>
<msub>
<mi>V</mi>
<mi>g</mi>
</msub>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
<mo>|</mo>
<mo>/</mo>
<mo>|</mo>
<msub>
<mi>V</mi>
<mi>T</mi>
</msub>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
<mo>|</mo>
<mo>)</mo>
</mrow>
</mrow>
<mi>l</mi>
</mfrac>
</mrow>
Wherein l is rod-like samples length, and ω is frequency,Represent the phase of direct wave at sample fixing end；Represent
The phase of sample free end direct wave, unwrap is phase unwrapping around function；
Step 6：The longitudinal wave velocity c (ω) and attenuation coefficient α (ω) of the rod-like samples obtained according to step 5, calculating obtain material
The storage modulus E ' and fissipation factor tan (δ) of material：
<mrow>
<msup>
<mi>E</mi>
<mo>&prime;</mo>
</msup>
<mo>=</mo>
<mi>&rho;</mi>
<mi>c</mi>
<msup>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
<mn>2</mn>
</msup>
<mi>c</mi>
<mi>o</mi>
<mi>s</mi>
<mo>&lsqb;</mo>
<mn>2</mn>
<msup>
<mi>sin</mi>
<mrow>
<mo>-</mo>
<mn>1</mn>
</mrow>
</msup>
<mrow>
<mo>(</mo>
<mfrac>
<mrow>
<mi>&alpha;</mi>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
<mi>c</mi>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
</mrow>
<mi>&omega;</mi>
</mfrac>
<mo>)</mo>
</mrow>
<mo>&rsqb;</mo>
</mrow>
<mrow>
<mi>t</mi>
<mi>a</mi>
<mi>n</mi>
<mrow>
<mo>(</mo>
<mi>&delta;</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<mi>t</mi>
<mi>a</mi>
<mi>n</mi>
<mrow>
<mo>(</mo>
<mn>2</mn>
<msup>
<mi>sin</mi>
<mrow>
<mo>-</mo>
<mn>1</mn>
</mrow>
</msup>
<mo>(</mo>
<mfrac>
<mrow>
<mi>&alpha;</mi>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
<mi>c</mi>
<mrow>
<mo>(</mo>
<mi>&omega;</mi>
<mo>)</mo>
</mrow>
</mrow>
<mi>&omega;</mi>
</mfrac>
<mo>)</mo>
<mo>)</mo>
</mrow>
</mrow>
Wherein ρ is density of material, and δ represents the phase of multiple Young's modulus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710413324.1A CN107271301B (en) | 2017-06-05 | 2017-06-05 | It is a kind of based on direct wave extract viscoelastic material answer Young's modulus measurement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710413324.1A CN107271301B (en) | 2017-06-05 | 2017-06-05 | It is a kind of based on direct wave extract viscoelastic material answer Young's modulus measurement method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107271301A true CN107271301A (en) | 2017-10-20 |
| CN107271301B CN107271301B (en) | 2019-06-21 |
Family
ID=60065688
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710413324.1A Active CN107271301B (en) | 2017-06-05 | 2017-06-05 | It is a kind of based on direct wave extract viscoelastic material answer Young's modulus measurement method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107271301B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102184332A (en) * | 2011-05-17 | 2011-09-14 | 中国船舶重工集团公司第七二五研究所 | Method for expanding dynamic mechanical test data of viscous-elastic material out of test frequency |
-
2017
- 2017-06-05 CN CN201710413324.1A patent/CN107271301B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102184332A (en) * | 2011-05-17 | 2011-09-14 | 中国船舶重工集团公司第七二五研究所 | Method for expanding dynamic mechanical test data of viscous-elastic material out of test frequency |
Non-Patent Citations (4)
| Title |
|---|
| K. MAHATA, ETC.: "Using boundary conditions for estimation of complex modulus from flexural wave experiments", 《IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY》 * |
| LIANG SUN, ETC.: "Measurement of characteristic impedance and wave number of porous material using", 《JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA》 * |
| 侯宏等: "基于共振法的黏弹性细棒力学参数宽频测试", 《振动与冲击》 * |
| 贺西平等: "强迫振动方法确定粘弹性细棒的复杨氏模量", 《声学学报》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107271301B (en) | 2019-06-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2111535B1 (en) | Vibrating wire sensor using spectral analysis | |
| EP3987283B1 (en) | Method and system for analysing a test piece using a vibrational response signal | |
| US8671758B2 (en) | System and method for measuring the frequency of a vibrating object | |
| US20160108729A1 (en) | Method and device for the concurrent determination of fluid density and viscosity in-situ | |
| CN201408105Y (en) | Time-sharing fast steady-state sine sweep frequency shock excitation frequency response function measuring system | |
| Jain et al. | Magneto-acoustic sensors for measurement of liquid temperature, viscosity and density | |
| CN105738479A (en) | Method and device for testing small strain viscoelasticity parameter of geotechnical engineering material through bending elements | |
| Norisuye et al. | Simultaneous evaluation of ultrasound velocity, attenuation and density of polymer solutions observed by multi-echo ultrasound spectroscopy | |
| Schaeffer et al. | Dynamic modulus and damping ratio measurements from free-free resonance and fixed-free resonant column procedures | |
| JPH10160715A (en) | Measuring method for shear rigidity of soil | |
| CN107271301A (en) | A kind of multiple Young's modulus measuring method of viscoelastic material extracted based on direct wave | |
| CN105259373B (en) | Steel ball emitter and accelerometer Calibration of Dynamic system comprising the device | |
| JP4121426B2 (en) | Method and apparatus for measuring coefficient for vibration energy loss | |
| Muir et al. | Elastic softening of sandstone due to a wideband acoustic pulse | |
| Kulik et al. | Physical principles of methods for measuring viscoelastic properties | |
| Morrow et al. | Dynamic viscoelastic characterization of solid food materials | |
| Wei et al. | Complex Young's modulus measurement by incident wave extracting in a thin resonant bar | |
| CN108802195B (en) | Test device and method for measuring transverse wave velocity of core sample | |
| Burks et al. | An experimental-numerical investigation of the face-to-face sensor characterization technique | |
| Filipiak et al. | Surface acoustic waves for the detection of small vibrations | |
| CN106769561A (en) | A kind of lower Hollow Transmission Shafts mechanics parameter lossless detection method of temperature loading effect | |
| Hou et al. | Broadband dynamic parameters measurement by longitudinal vibration testing using pulse wave | |
| CN202939158U (en) | Young modulus measuring apparatus adopting resonance method | |
| Hou et al. | Estimation of dynamic paramaters for viscoelastic materials by longitudinal vibration testing using pulse method | |
| JP7352329B2 (en) | Viscoelasticity measurement method and viscoelasticity measurement device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |