CN104101471A - Broadband damping treatment method of vibration test clamp - Google Patents
Broadband damping treatment method of vibration test clamp Download PDFInfo
- Publication number
- CN104101471A CN104101471A CN201410323131.3A CN201410323131A CN104101471A CN 104101471 A CN104101471 A CN 104101471A CN 201410323131 A CN201410323131 A CN 201410323131A CN 104101471 A CN104101471 A CN 104101471A
- Authority
- CN
- China
- Prior art keywords
- damping
- wideband
- test fixture
- vibration
- test
- 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
Landscapes
- Vibration Prevention Devices (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
The invention belongs to the vibration test technical field and relates to a method for improving the controllability and accuracy of vibration tests, in particular a broadband damping treatment method of a vibration test clamp. The method includes the steps of broadband damping glue production, test clamp preparation and broadband damping glue perfusion. According to the broadband damping treatment method of the invention, special viscoelasticity polymers are filled in the test clamp, and therefore, the modal damping of the vibration test clamp can be increased by 1 to 2 numerical levels, and the vibration test clamp has an excellent modification effect in a wide frequency range from 200 to 2000Hz; and the density of the produced broadband damping glue is adjustable, is low in cost and has a wide application range. With the test clamp treated by the method of the invention adopted, single-degree-of-freedom or multi-degree-of-freedom resonant system quality factors can be significantly reduced, and vibration control precision can be improved, and over-test and under-test can be effectively avoided, and test cost can be saved, and risks of damage to tested products which are caused by the amplification of vibration stress quantity values can be decreased.
Description
Technical field
The invention belongs to vibration test technical field, relate to a kind of method that improves vibration test controllability and accuracy, be specifically related to a kind of wideband damp treating method of vibration test fixture.
Background technology
Vibration test is upper by being arranged on vibration rig (platform) by trial product by test fixture, by controlling vibrational spectra shape and magnitude, and the pilot project of examination product to vibration environment tolerance.The test fixture using in vibration test comprises universal fixturing and unit clamp, and wherein universal fixturing is generally shaking table expanding table top.Test fixture is for the connection of shaking table and test specimen, and its one end rigidity is arranged on shaking table moving component, and the other end and test specimen are rigidly connected.The design of test fixture and application belong to the category of vibration test technology.
There is not resonance in desirable test fixture, the vibration force that shaking table can be produced passes to test specimen without distortion in its operating frequency range.Large-scale experiment fixture can produce resonance in operating frequency range, and resonance can be amplified vibration stress, makes to vibrate distortion, is unfavorable for that vibration stress applies.
The solution route of vibration test fixture resonance problem is mainly the resonant frequency that improves test fixture at present, mainly realizes by increasing fixture rigidity.But this method has often increased weight and the manufacturing cost of fixture, and cannot be suitable for large scale test fixture at all.
Suzhou Dongling Vibration Test Instrument Co., Ltd's disclosed patent " a kind of method that reduces quality factor in vibration environment " (publication number CN 101034046) in 2007, a kind of method that improves damping capacity by combine a kind of nonmetallic materials (rubber, plastic cement or resin material) on metal basic building block has been proposed, the field relating to is the design and production of vibration rig, not for vibration test technology.This patented method is applicable to the test product of metal cylinder structure, nonmetallic materials is combined in to the inwall of metal cylinder, to improve the damping of test product.For the test fixture of the configurations of applying in vibration test, this patented method is also inapplicable.In addition, this patented method does not provide the feature such as particular type, composition of required nonmetallic materials, does not clearly provide the applicable frequency range of the method yet.
T54/T60 damping material is the patented product (patent No. 93107379.0) that has Inst. of Marine Chemical Engineering exploitation, is mainly used in the vibration and noise reducing processing of naval vessel wall panel structure.The constrained damping structure that this material adopts damping layer to coordinate with restraint layer in application process.Its damping layer part has good damping characteristic, but, directly after perfusion T54/T60 damping layer material, although the damping ratio of test fixture increase to some extent, exist easily take off with metal construction after solidifying close, the problem such as effective vibration damping frequency range narrow (low-frequency effect is limited).
Summary of the invention
The object of the invention is to propose a kind of test fixture that improves, particularly large scale fixture is in the damping ratio of resonant frequency, reduce quality factor q, reduce vibration and transmit distortion, significantly reduce vibration test control difficulty, guarantee the wideband damp treating method of vibration test success, the efficient vibration test fixture of implementing.Technical solution of the present invention is,
(1) prepare wideband, high damping glue
The damping layer material of T54/T60 damping paint is carried out to modification, and damping layer material comprises A, two kinds of components of B, and concrete grammar is as follows:
(1) in the A component of the damping layer material of T54/T60 damping paint, adding massfraction is 10～30% liquid rubber constituents;
(2) in the B component of the damping layer material of T54/T60 damping paint, adding massfraction is 2～10% polyvalent alcohol, the heavy filling material that massfraction is 15～50%, the density adjuster that massfraction is 0～3%;
(2) preparation of test fixture
(1) design and manufacture test fixture and cavity is set on fixture according to the specific requirement of vibration test and by the size of trial product, structure, Modal Features, the ratio of the volume of cavity and fixture cumulative volume is greater than 0.2, cavity inside surface to test fixture carries out oil removal treatment, and the cavity inside surface after to oil removing is dried processing with pressurized air or hot-air;
(2) the wideband damping processing of test fixture
The wideband damping glue A preparing, B component are mixed according to mass ratio 4:1～1:1 in the temperature environment of 0～40 DEG C, and potpourri is fully stirred, mixing time is 1～10min, until A, B component mix, after mixing, static 1～10min, overflows the bubble entraining into;
(3) perfusion wideband damping glue
The A mixing, B component mixture are filled in test fixture cavity, and carry out encapsulation process leave standstill curing 24～72h in the temperature environment of 0～40 DEG C after, the wideband damping glue of perfusion accounts for 10%～50% of the rear test fixture gross mass of perfusion, obtains thus wideband damping test fixture.
Described liquid rubber constituents is carboxylated nbr, hydroxyl styrene-butadiene rubber or liquid butylhydroxy rubber.
Described polyol component is diglycol or dipropylene glycol.
Described heavy filling material is barium sulphate powder or ground chalk powder.
Described density adjuster is glass fibre or hollow glass micro-ball.
Described test fixture cavity inside surface is anodic oxidation, aluminum alloy chemically oxidation, the chemical oxidation of magnesium alloy or the passivated surface of steel of bare metal surface or aluminium alloy anode oxide, magnesium alloy.
Beneficial effect of the present invention is, the present invention is by filling the mode of special viscoelastic polymer at test fixture, the modal damping of vibration test fixture can be improved to 1～2 order of magnitude, and in the wider frequency range of 200～2000Hz, all there is good modified effect; The wideband damping glue density of preparation is adjustable, and cost is low, applied widely; Solidify after, damping material stability is high, long-lasting good, remains high viscoelasticity state, there will not be the later stage harden gradually lost efficacy problem; Can in vibration environment, keep and the combining closely of metal construction; Application is through the test fixture of processing of the present invention, can significantly reduce single-degree-of-freedom or multiple degrees of freedom resonator system quality factor, improve vibration control precision, effectively avoid the generation of overtesting and undertesting, save test funds, and reduce because vibration stress value expands and cause the risk of being damaged by trial product.
Embodiment
Below will be specifically described the present invention, but the present invention's scope required for protection is not limited to the described scope of embodiment.
Embodiment 1
60 × 60 × 5cm aluminium alloy universal fixturing (net weight 10.6kg) is carried out to wideband, high damping processing, and concrete implementation step is:
1, the preparation of wideband damping glue product: add massfraction and be 15% carboxylated nbr in T54/T60 damping paint damping layer material A component.In the B of original product component, add massfraction and be 2% diglycol; To add massfraction be 50% barium sulphate powder, and to add massfraction be 2.5% glass fibre.
2, the preparation of aluminium alloy universal fixturing: adopt acetone to carry out oil removal treatment to the universal fixturing being obtained by the machine work of aluminium alloy thick plate material, and adopt pressurized air to be dried processing.
3, the wideband of aluminium alloy universal fixturing, high damping processing: wideband damping glue A, B component are mixed in the temperature environment of 25 DEG C to mechanical raking 2min according to the mass ratio of 5:2.After mixing, static 5min.Wideband damping glue A, the B component mixture of 6.5kg are filled in the bottom cavity of aluminium alloy universal fixturing, and in the temperature environment of 25 DEG C, leave standstill curing 24h.Obtain thus the aluminium alloy universal fixturing of wideband, high damping processing.The wideband damping glue of pouring in the present embodiment accounts for 38% of perfusion rear jig gross mass.
Use hammering method to measure wideband, high damping aluminium alloy universal fixturing after treatment Free Modal, testing apparatus is LMS SCADAS310 data acquisition equipment and LMS Test.Lab model analysis software, when test, make fixture in elasticity status of support, selection is positioned at the point of one jiao of fixture as vibratory response measurement point, knock successively 25 measuring points on table top, obtain 25 groups of frequency response functions of table top, use time domain multiple degrees of freedom modal identification method identification fixture mode, obtain thus modal damping result as shown in table 1.
In table 1 embodiment 1, wideband high damping is processed the modal damping test result of rear aluminium alloy universal fixturing
| Mode | Frequency (Hz) | Damping ratio (%) |
| 1 | 281 | 2.11 |
| 2 | 356 | 3.90 |
| 3 | 516 | 7.69 |
| 4 | 755 | 15.79 |
| 5 | 926 | 11.61 |
| 6 | 1186 | 18.37 |
| 7 | 1359 | 7.55 |
| 8 | 1818 | 14.55 |
Comparative example
Use hammering method to measure undressed aluminium alloy universal fixturing Free Modal in embodiment 1, obtain modal damping result as shown in table 2.
According to method described in embodiment 1, directly adopt the damping layer material of T54/T60 damping paint to carry out damping processing to identical aluminium alloy universal fixturing, the mass ratio of component A, B is 5:2, pouring quality is all 6.5kg.Use hammering method to measure the Free Modal of processing rear jig, result is as shown in table 3.
Can be found out by embodiment 1 and comparative example thereof, adopt the art of this patent the modal damping of aluminium alloy universal fixturing can be improved to 1～2 order of magnitude; With respect to the T54/T60 damping layer material without wideband, high damping modification, low frequency part (200～800Hz) damping ratio improves 2～3 times, and HFS damping ratio improves 1～2 times.
The modal damping test result of the undressed aluminium alloy universal fixturing of table 2 (60cm)
| Mode | Frequency (Hz) | Damping ratio (%) |
| 1 | 338 | 0.08 |
| 2 | 442 | 0.12 |
| 3 | 639 | 0.26 |
| 4 | 877 | 0.15 |
| 5 | 1332 | 0.18 |
| 6 | 1336 | 0.17 |
| 7 | 1429 | 0.08 |
| 8 | 1657 | 0.14 |
The modal damping result of aluminium alloy universal fixturing (60cm) after table 3 adopts T54/T60 damping layer material to process
| Mode | Frequency (Hz) | Damping ratio (%) |
| 1 | 286 | 0.69 |
| 2 | 360 | 1.25 |
| 3 | 519 | 2.74 |
| 4 | 706 | 7.70 |
| 5 | 1117 | 5.30 |
| 6 | 1306 | 11.24 |
| 7 | 1701 | 10.81 |
Embodiment 2
1.25 × 1.25 × 0.6m magnesium alloy universal fixturing (net weight 680kg) is carried out to wideband, high damping processing, and concrete implementation step is:
1, the preparation of wideband damping glue product: add massfraction and be 20% hydroxyl styrene-butadiene rubber in T54/T60 damping paint damping layer material A component.In the B of original product component, add massfraction and be 6% diglycol; To add massfraction be 30% ground chalk powder, and to add massfraction be 1% hollow glass micro-ball.
2, the preparation of magnesium alloy universal fixturing: adopt monoblock cast to manufacture fixture blank, machining obtains accurate dimension, and carries out anodized surface processing.Adopt the magnesium alloy universal fixturing internal cavities inside surface after the oxidation of anhydrous alcohol antianode to carry out oil removal treatment, and adopt pressurized air to be dried processing to cavity inside surface.
3, the wideband of magnesium alloy universal fixturing, high damping processing: wideband damping glue A, B component are mixed in the temperature environment of 5 DEG C to mechanical raking 10min according to the mass ratio of 4:1.After mixing, static 10min.Wideband damping glue A, the B component mixture of 300kg are filled in the part cavity of magnesium alloy universal fixturing inside.In the temperature environment of 5 DEG C, leave standstill and solidify 72h.Obtain thus the magnesium alloy universal fixturing of wideband, high damping processing.The wideband damping glue of pouring in the present embodiment accounts for approximately 30% of perfusion rear jig gross mass.Finally adopt papery adhesive tape to carry out encapsulation process to cavity opening, table top side plate is installed.
Use hammering method to measure wideband, high damping magnesium alloy universal fixturing after treatment Free Modal, when test, make fixture in elasticity status of support, selection is positioned at the point of one jiao of fixture as vibratory response measurement point, knock successively 36 measuring points on fixture, obtain 36 groups of frequency response functions, use time domain multiple degrees of freedom modal identification method identification vibration test fixture mode, obtain thus modal damping result as shown in table 4.
The modal damping test result of magnesium alloy universal fixturing (1.25m) after table 4 adopts wideband damping glue to process
| Mode | Frequency (Hz) | Damping ratio (%) |
| 1 | 434 | 7.52 |
| 2 | 526 | 8.64 |
| 3 | 967 | 13.78 |
| 4 | 1263 | 9.47 |
| 5 | 1655 | 9.90 |
Comparative example
Use hammering method to measure in embodiment 2 Free Modal without the magnesium alloy universal fixturing of wideband, high damping processing, obtain modal damping result as shown in table 5.
The original modal damping result of table 5 magnesium alloy universal fixturing (1.25m)
| Mode | Frequency (Hz) | Damping ratio (%) |
| 1 | 509 | 2.33 |
| 2 | 645 | 0.56 |
| 3 | 676 | 0.99 |
| 4 | 708 | 0.96 |
| 5 | 732 | 0.75 |
| 6 | 1005 | 1.73 |
| 7 | 1144 | 0.69 |
| 8 | 1206 | 0.77 |
| 9 | 1288 | 0.74 |
| 10 | 1564 | 1.85 |
| 11 | 1678 | 1.22 |
Embodiment 3
To diameter 35cm, the aluminium alloy unit clamp of high 40cm (net weight 7.5kg) carries out wideband, high damping processing, and concrete implementation step is:
1, the preparation of wideband damping glue product: add massfraction and be 30% hydroxyl phenylpropyl alcohol rubber in T54/T60 damping paint damping layer material A component.In the B of original product component, add massfraction and be 10% dipropylene glycol; The ground chalk powder that interpolation massfraction is 15%.
2, the preparation of aluminium alloy unit clamp: according to by the feature of trial product, adopt the method for casting, machine work refine to manufacture aluminium alloy unit clamp, and carry out anodized surface processing.Adopt acetone to carry out oil removal treatment to the aluminium alloy unit clamp internal cavities surface through anodized, adopt pressurized air to be dried processing to cavity inside surface.
3, the wideband of aluminium alloy unit clamp, high damping processing: wideband damping glue A, B component are mixed in the temperature environment of 35 DEG C to mechanical raking 5min according to the mass ratio of 1:1.After mixing, static 2min.Wideband damping glue A, the B component mixture of 1.7kg are filled in the cavity of fixture inside.And in the temperature environment of 35 DEG C leave standstill solidify 48h.Obtain thus the aluminium alloy unit clamp of wideband, high damping processing.The wideband damping glue of pouring in the present embodiment accounts for approximately 18% of perfusion rear jig gross mass.
Use hammering method to measure aluminium alloy unit clamp Free Modal after treatment, knock successively 20 measuring points on fixture, obtain 20 groups of frequency response functions, use time domain multiple degrees of freedom modal identification method identification fixture mode, obtain thus modal damping result as shown in table 6.
The modal damping test result of aluminium alloy unit clamp (35cm) after table 6 adopts wideband damping glue to process
| Mode | Frequency (Hz) | Damping ratio (%) |
| 1 | 866 | 9.64 |
| 2 | 1117 | 8.11 |
| 3 | 1439 | 10.65 |
| 4 | 1726 | 7.12 |
Comparative example
Use hammering method to measure in embodiment 3 Free Modal without the aluminium alloy unit clamp (35cm) of wideband, high damping processing, obtain modal damping result as shown in table 7.
The original modal damping test result of table 7 aluminium alloy unit clamp (35cm)
| Mode | Frequency (Hz) | Damping ratio (%) |
| 1 | 958 | 0.03 |
| 2 | 1321 | 0.04 |
| 3 | 1648 | 0.15 |
| 4 | 1993 | 0.17 |
Claims (6)
1. a wideband damp treating method for vibration test fixture, is characterized in that,
(1) prepare wideband damping glue
The damping layer material of T54/T60 damping paint is carried out to modification, and damping layer material comprises A, two kinds of components of B, and concrete grammar is as follows:
(1) in the A component of the damping layer material of T54/T60 damping paint, adding massfraction is 10～30% liquid rubber constituents;
(2) in the B component of the damping layer material of T54/T60 damping paint, adding massfraction is 2～10% polyvalent alcohol, the heavy filling material that massfraction is 15～50%, the density adjuster that massfraction is 0～3%;
(2) preparation of test fixture
(1) design and manufacture test fixture and cavity is set on fixture according to the specific requirement of vibration test and by the size of trial product, structure, Modal Features, the ratio of the volume of cavity and fixture cumulative volume is greater than 0.2, cavity inside surface to test fixture carries out oil removal treatment, and the cavity inside surface after to oil removing is dried processing with pressurized air or hot-air;
(2) the wideband damping processing of test fixture
The wideband damping glue A preparing, B component are mixed according to mass ratio 4:1～1:1 in the temperature environment of 0～40 DEG C, and potpourri is fully stirred, mixing time is 1～10min, until A, B component mix, after mixing, static 1～10min, overflows the bubble entraining into;
(3) perfusion wideband damping glue
The A mixing, B component mixture are filled in test fixture cavity, and carry out encapsulation process leave standstill curing 24～72h in the temperature environment of 0～40 DEG C after, the wideband damping glue of perfusion accounts for 10%～50% of the rear test fixture gross mass of perfusion, obtains thus wideband damping test fixture.
2. the wideband damp treating method of a kind of vibration test fixture according to claim 1, is characterized in that, described liquid rubber constituents is carboxylated nbr, hydroxyl styrene-butadiene rubber or liquid butylhydroxy rubber.
3. the wideband damp treating method of a kind of vibration test fixture according to claim 1, is characterized in that, described polyol component is diglycol or dipropylene glycol.
4. the wideband damp treating method of a kind of vibration test fixture according to claim 1, is characterized in that, described heavy filling material is barium sulphate powder or ground chalk powder.
5. the wideband damp treating method of a kind of vibration test fixture according to claim 1, is characterized in that, described density adjuster is glass fibre or hollow glass micro-ball.
6. the wideband damp treating method of a kind of vibration test fixture according to claim 1, it is characterized in that, described test fixture cavity inside surface is anodic oxidation, aluminum alloy chemically oxidation, the chemical oxidation of magnesium alloy or the passivated surface of steel of bare metal surface or aluminium alloy anode oxide, magnesium alloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410323131.3A CN104101471B (en) | 2014-07-08 | 2014-07-08 | The wideband damp treating method of a kind of vibration test fixture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410323131.3A CN104101471B (en) | 2014-07-08 | 2014-07-08 | The wideband damp treating method of a kind of vibration test fixture |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104101471A true CN104101471A (en) | 2014-10-15 |
| CN104101471B CN104101471B (en) | 2016-06-08 |
Family
ID=51669802
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410323131.3A Active CN104101471B (en) | 2014-07-08 | 2014-07-08 | The wideband damp treating method of a kind of vibration test fixture |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104101471B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112765839A (en) * | 2020-12-17 | 2021-05-07 | 哈尔滨工程大学 | Design method of metal rubber component |
| CN114459716A (en) * | 2022-04-13 | 2022-05-10 | 天津航天瑞莱科技有限公司 | Multi-frequency-band vibration amplifying device with adjustable synchronous amplification |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN85201134U (en) * | 1985-04-30 | 1986-04-09 | 西安交通大学 | Air compressor exhaust unit with noise silencer |
| JP2006126125A (en) * | 2004-11-01 | 2006-05-18 | Sony Corp | Vibration tester |
| CN2848517Y (en) * | 2005-12-14 | 2006-12-20 | 霍玉杰 | Vibration shaped building block and composite inner carity of ground tile mould |
| CN101034046A (en) * | 2006-12-29 | 2007-09-12 | 苏州东菱振动试验仪器有限公司 | Method for lowering quality factoring in vibration environment |
| CN203585184U (en) * | 2013-08-02 | 2014-05-07 | 南京龙吟精密科技有限公司 | Vibration absorber based on polyurethane fillers |
-
2014
- 2014-07-08 CN CN201410323131.3A patent/CN104101471B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN85201134U (en) * | 1985-04-30 | 1986-04-09 | 西安交通大学 | Air compressor exhaust unit with noise silencer |
| JP2006126125A (en) * | 2004-11-01 | 2006-05-18 | Sony Corp | Vibration tester |
| CN2848517Y (en) * | 2005-12-14 | 2006-12-20 | 霍玉杰 | Vibration shaped building block and composite inner carity of ground tile mould |
| CN101034046A (en) * | 2006-12-29 | 2007-09-12 | 苏州东菱振动试验仪器有限公司 | Method for lowering quality factoring in vibration environment |
| CN203585184U (en) * | 2013-08-02 | 2014-05-07 | 南京龙吟精密科技有限公司 | Vibration absorber based on polyurethane fillers |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112765839A (en) * | 2020-12-17 | 2021-05-07 | 哈尔滨工程大学 | Design method of metal rubber component |
| CN112765839B (en) * | 2020-12-17 | 2022-04-01 | 哈尔滨工程大学 | Design method of metal rubber component |
| CN114459716A (en) * | 2022-04-13 | 2022-05-10 | 天津航天瑞莱科技有限公司 | Multi-frequency-band vibration amplifying device with adjustable synchronous amplification |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104101471B (en) | 2016-06-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Chen et al. | Experimental study on fatigue properties of normal and rubberized self-compacting concrete under bending | |
| CN102564856B (en) | M integral measurement method based on plastic multi-defect material relevant to digital image | |
| Bai et al. | Study on vibration alleviating properties of glass fiber reinforced polymer concrete through orthogonal tests | |
| Lee et al. | Effect of fiber orientation on acoustic and vibration response of a carbon fiber/epoxy composite plate: Natural vibration mode and sound radiation | |
| CN108225950B (en) | Roadbed soil dynamic resilience modulus estimation method based on substrate suction and stress state | |
| Wang et al. | Experimental investigation and FE analysis on constitutive relationship of high strength aluminum alloy under cyclic loading | |
| CN104101471A (en) | Broadband damping treatment method of vibration test clamp | |
| CN112051141B (en) | Construction method of composite material strain rate related compression constitutive model | |
| CN107784190A (en) | Ship Structure wideband line spectrum vibration noise Fast Prediction method | |
| CN104792485A (en) | Testing method of motor damping feature recognition | |
| CN105001594A (en) | Earthquake physical model material and model | |
| CN106197915A (en) | A kind of position the method that oscillating aging controls timeliness part fatigue life | |
| CN111783332B (en) | Finite element simulation method for vibration accumulation deformation of compression non-linear change and shear sudden change characteristic material | |
| Ren et al. | Correction of transducers mass effects from the measured frfs in hammer impact testing | |
| CN106706190A (en) | Method of determining impact-load equivalent static load | |
| Żymankowska-Kumon et al. | Comparison of the emission of aromatic hydrocarbons from moulding sands with furfural resin with the low content of furfuryl alcohol and different activators | |
| RU2553862C1 (en) | Vibration-and-noise absorbing sheet material and method of vibration-and-noise killing | |
| CN104502575A (en) | Target, and device and method for testing early-age shrinkage of magnesium phosphate cement by use of target | |
| CN103226053A (en) | Operational modal shape testing system for nonlinear material structure | |
| RU140137U1 (en) | VIBRATING-ABSORBING SHEET MATERIAL | |
| Mo et al. | Simulation and Random Vibration Test of Structural Dynamic Characteristics of Vacuum Tube | |
| Wang et al. | Damage processes of polypropylene fiber reinforced mortar in different fiber content revealed by acoustic emission behavior | |
| Ren et al. | Correction of multiple transducers masses effects from the measured FRFs | |
| Li et al. | Analytical solution for vibration of continuously varying-Thickness beams resting on pasternak elastic foundations | |
| Li et al. | Structural Design and Characteristic Research of Product Vibration Test Fixture Based on High Frequency Response Characteristics |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |