CN104101471B - The wideband damp treating method of a kind of vibration test fixture - Google Patents
The wideband damp treating method of a kind of vibration test fixture Download PDFInfo
- Publication number
- CN104101471B CN104101471B CN201410323131.3A CN201410323131A CN104101471B CN 104101471 B CN104101471 B CN 104101471B CN 201410323131 A CN201410323131 A CN 201410323131A CN 104101471 B CN104101471 B CN 104101471B
- Authority
- CN
- China
- Prior art keywords
- wideband
- test fixture
- damping
- fixture
- 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.)
- Active
Links
Landscapes
- Sampling And Sample Adjustment (AREA)
- Vibration Prevention Devices (AREA)
Abstract
The invention belongs to vibration test technical field, it relates to a kind of method improving vibration test controllability and accuracy, it is specifically related to the wideband damp treating method of a kind of vibration test fixture. The inventive method comprises (one) and prepares wideband damping glue, the preparation of (two) test fixture, and (three) pour into wideband damping glue. The present invention by filling the mode of special viscoelastic polymer at test fixture, it is possible to the modal damping of vibration test fixture is improved 1��2 order of magnitude, and all has good modified effect in the wider frequency range of 200��2000Hz; The wideband damping glue density of preparation is adjustable, and cost is low, applied widely; Apply the test fixture through the present invention's process, can significantly reduce single degree of freedom or multiple degree of freedom resonance system figure of merit, improve vibration control precision, effectively avoided testing and owing the generation of test, save test funds, and reduce owing to vibratory stress value expands the risk causing tested product to damage.
Description
Technical field
The invention belongs to vibration test technical field, it relates to a kind of method improving vibration test controllability and accuracy, it is specifically related to the wideband damp treating method of a kind of vibration test fixture.
Background technology
Vibration test is arranged on vibration test equipment (platform) by tested product by test fixture, and by control vibration spectrum shape and magnitude, examination product is to the test subject of vibration environment tolerance. The test fixture used in vibration test comprises universal fixturing and unit clamp, and wherein universal fixturing is generally shaking table expanding table top. Test fixture is used for the connection of shaking table and test specimen, and its one end rigidity is arranged on shaking table moving parts, and the other end and test specimen are rigidly connected. The design and devdlop of test fixture belongs to the category of vibration test technology.
There is not resonance in desirable test fixture, the vibration power that shaking table produces can be passed to test specimen without distortion in its operating frequency range. Large-scale experiment fixture, can produce resonance in operating frequency range, and vibratory stress can be amplified by resonance, makes vibration distortion, is unfavorable for that vibratory stress applies.
The solution route of vibration test fixture resonance problem mainly improves the resonant frequency of test fixture at present, realizes mainly through increasing fixture rigidity. But, this kind of method often adds weight and the manufacturing cost of fixture, and cannot be suitable for by large size test fixture at all.
Patent disclosed in Suzhou Dongling Vibration Test Instrument Co., Ltd 2007 " a kind of method reducing quality factor in vibration environment " (publication number CN101034046), propose a kind of method being improved damping capacity by a kind of non-metallic material (rubber, plastic cement or resin material) of combination on the basic component of metal, the field related to is the design and production of vibration test equipment, not for vibration test technology.This patented method is applicable to the test product of metal cylinder structure, and non-metallic material are combined in the inwall of metal cylinder, to improve the damping of test product. For the test fixture that the structure of application in vibration test is different, this patented method is not suitable for. In addition, this patented method does not provide the features such as the particular type of required non-metallic material, composition, does not clearly provide the range of frequency that the method is suitable for yet.
T54/T60 damping material is the patented product (patent No. 93107379.0) having Inst. of Marine Chemical Engineering to develop, and is mainly used in the vibration and noise reducing process of naval vessel wall panel structure. This material adopts the constrained damping structure that damping layer coordinates with restraint layer in application process. Its damping layer part has good damping characteristic, but, after directly pouring into T54/T60 damping layer material, although the subsidence ratio of test fixture increases to some extent, but deposit the problems such as easy after hardening and the de-conjunction of metal construction, effectively vibration damping range of frequency narrow (low-frequency effect is limited).
Summary of the invention
It is an object of the invention to propose a kind of raising test fixture, particularly large size fixture is in the subsidence ratio of resonant frequency, reduce quality factor q, reduce vibration passing distortion, much slower vibration test control difficulty, it is ensured that the wideband damp treating method of the vibration test fixture of vibration test success, efficient implementation. The technical solution of the present invention is,
(1) wideband, high damping glue is prepared
The damping layer material of T54/T60 damping paint is carried out modification, and damping layer material comprises A, B two kinds of components, and concrete grammar is as follows:
(1) in the component A of the damping layer material of T54/T60 damping paint, the fluid rubber constituents that massfraction is 10��30% is added;
(2) adding the polyvalent alcohol that massfraction is 2��10% in the B component of the damping layer material of T54/T60 damping paint, massfraction is the heavy matter weighting material of 15��50%, and massfraction is the density adjuster of 0��3%;
(2) preparation of test fixture
(1) design according to the size of the specific requirement of vibration test and tested product, structure, mode feature and manufacture test fixture and cavity is set on fixture, the volume of cavity and the ratio of fixture cumulative volume are greater than 0.2, the cavity internal surface of test fixture is carried out oil removal treatment, and with pressurized air or warm air, the cavity internal surface after oil removing is dried process;
(2) the wideband impedance bundary of test fixture
The wideband damping glue A prepared, B component are mixed according to mass ratio 4:1��1:1 in the temperature environment of 0��40 DEG C, and fully stirred by mixture, and churning time is 1��10min, until A, B component mix, after mixing, static 1��10min, makes the bubble entrained into overflow;
(3) wideband damping glue is poured into
The A mixed, B component mixture are filled in test fixture cavity, and carry out encapsulation process after leaving standstill solidification 24��72h in the temperature environment of 0��40 DEG C, the wideband damping glue of perfusion accounts for the 10%��50% of the rear test fixture total mass of perfusion, thus obtains wideband damping test fixture.
Described fluid rubber constituents is carboxylated nbr, hydroxyl styrene-butadiene rubber(SBR) or liquid butylhydroxy rubber.
Described polyhydroxy reactant is glycol ether or dipropylene glycol.
Described heavy matter weighting material is barium sulfate powder or water-ground limestone powder.
Described density adjuster is glass fibre or hollow glass micro-ball.
Described test fixture cavity internal surface is the naked surface of metal or aluminium alloy anode oxide, the anodic oxidation of magnesium alloy, aluminum alloy chemically oxidation, the chemical oxidation of magnesium alloy or the passive surface of steel.
The useful effect of the present invention is, the present invention by filling the mode of special viscoelastic polymer at test fixture, the modal damping of vibration test fixture can be improved 1��2 order of magnitude, and all there is good modified effect in the wider frequency range of 200��2000Hz;The wideband damping glue density of preparation is adjustable, and cost is low, applied widely; After solidification, damping material stability height, long-acting property is good, remains high visco-elastic state, there will not be the problem that the later stage hardens and lost efficacy gradually; Can keep and the combining closely of metal construction in vibration environment; Apply the test fixture through the present invention's process, can significantly reduce single degree of freedom or multiple degree of freedom resonance system figure of merit, improve vibration control precision, effectively avoided testing and owing the generation of test, save test funds, and reduce owing to vibratory stress value expands the risk causing tested product to damage.
Embodiment
Hereinafter the present invention will be specifically described, but the claimed scope of the present invention is not limited to the scope described by embodiment.
Embodiment 1
60 �� 60 �� 5cm aluminium alloy universal fixturing (net weight 10.6kg) carries out wideband, high damping process, and concrete implementation step is:
1, the preparation of wideband damping glue product: add, in T54/T60 damping paint damping layer material component A, the carboxylated nbr that massfraction is 15%. The B component of original product is added the glycol ether that massfraction is 2%; Add the barium sulfate powder that massfraction is 50%, and add the glass fibre that massfraction is 2.5%.
2, the preparation of aluminium alloy universal fixturing: adopt acetone to carry out oil removal treatment the universal fixturing obtained by aluminium alloy thick plate material machining, and adopt pressurized air to be dried process.
3, the wideband of aluminium alloy universal fixturing, high damping process: wideband damping glue A, B component are mixed in the temperature environment of 25 DEG C according to the mass ratio of 5:2, mechanical stirring 2min. After mixing, static 5min. The wideband damping glue A of 6.5kg, B component mixture are filled in the bottom cavity of aluminium alloy universal fixturing, and in the temperature environment of 25 DEG C, leave standstill solidification 24h. Thus obtain the aluminium alloy universal fixturing of wideband, high damping process. In the present embodiment, the wideband damping glue of perfusion accounts for the 38% of the rear fixture total mass of perfusion.
Aluminium alloy universal fixturing Free Modal after using hammering method to measure wideband, high damping process, testing apparatus is LMSSCADAS310 data acquisition equipment and LMSTest.Lab modal analysis software, make fixture be in elasticity during test and support state, select the point being positioned at fixture one jiao as vibratory response measurement point, knock 25 measuring points on table top successively, obtain table top 25 groups and frequently ring function, use time domain multiple degree of freedom modal identification method identification fixture mode, thus obtain modal damping result as shown in table 1.
The modal damping test result of the rear aluminium alloy universal fixturing of wideband high damping process in table 1 embodiment 1
| Mode | Frequency (Hz) | Subsidence 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 adopting the damping layer material of T54/T60 damping paint that identical aluminium alloy universal fixturing is carried out damping process, the mass ratio of component A, B is 5:2, and pouring quality is all 6.5kg. The Free Modal of fixture after use hammering method measurement processing, result is as shown in table 3.
By embodiment 1 and comparative example thereof it may be seen that adopt the art of this patent the modal damping of aluminium alloy universal fixturing can be improved 1��2 order of magnitude; Relative to the T54/T60 damping layer material without wideband, high damping modification, low frequency part (200��800Hz) subsidence ratio improves 2��3 times, and high frequency part subsidence ratio improves 1��2 times.
The modal damping test result of the undressed aluminium alloy universal fixturing (60cm) of table 2
| Mode | Frequency (Hz) | Subsidence ratio (%) |
| 1 | 338 | 0.08 |
| 2 | 442 | 0.12 |
| 3 | 639 | 0.26 |
| 4 | 877 | 0.15 3 --> |
| 5 | 1332 | 0.18 |
| 6 | 1336 | 0.17 |
| 7 | 1429 | 0.08 |
| 8 | 1657 | 0.14 |
Table 3 adopts the modal damping result of the rear aluminium alloy universal fixturing (60cm) of T54/T60 damping layer material process
| Mode | Frequency (Hz) | Subsidence 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) carries out wideband, high damping process, and concrete implementation step is:
1, the preparation of wideband damping glue product: add the hydroxyl styrene-butadiene rubber(SBR) that massfraction is 20% in T54/T60 damping paint damping layer material component A. The B component of original product is added the glycol ether that massfraction is 6%; Add the water-ground limestone powder that massfraction is 30%, and add the hollow glass micro-ball that massfraction is 1%.
2, the preparation of magnesium alloy universal fixturing: adopting monoblock casting to manufacture fixture blank, mechanical workout obtains accurate dimension, and carries out anodized surface process. Magnesium alloy universal fixturing internal cavities internal surface after adopting raw spirit antianode to be oxidized carries out oil removal treatment, and adopts pressurized air that cavity internal surface is dried process.
3, the wideband of magnesium alloy universal fixturing, high damping process: wideband damping glue A, B component are mixed in the temperature environment of 5 DEG C according to the mass ratio of 4:1, mechanical stirring 10min. After mixing, static 10min. The wideband damping glue A of 300kg, B component mixture are filled in the part cavity of magnesium alloy universal fixturing inside. The temperature environment of 5 DEG C leaves standstill solidification 72h. Thus obtain the magnesium alloy universal fixturing of wideband, high damping process. In the present embodiment, the wideband damping glue of perfusion accounts for about the 30% of the rear fixture total mass of perfusion. Finally adopt Paper adhesive tape that cavity opening is carried out encapsulation process, table top side plate is installed.
Magnesium alloy universal fixturing Free Modal after using hammering method to measure wideband, high damping process, make fixture be in elasticity during test and support state, select the point being positioned at fixture one jiao as vibratory response measurement point, knock 36 measuring points on fixture successively, obtain 36 groups and frequently ring function, use time domain multiple degree of freedom modal identification method identification vibration test fixture mode, thus obtain modal damping result as shown in table 4.
Table 4 adopts the modal damping test result of the rear magnesium alloy universal fixturing (1.25m) of wideband damping glue process
| Mode | Frequency (Hz) | Subsidence ratio (%) |
| 1 | 434 | 7.52 |
| 2 | 526 | 8.64 |
| 3 | 967 | 13.78 4 --> |
| 4 | 1263 | 9.47 |
| 5 | 1655 | 9.90 |
Comparative example
Use hammering method to measure in embodiment 2 Free Modal of the magnesium alloy universal fixturing processed without wideband, high damping, 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) | Subsidence 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 (net weight 7.5kg) of high 40cm carries out wideband, high damping process, and concrete implementation step is:
1, the preparation of wideband damping glue product: add the hydroxyl phenylpropyl alcohol rubber that massfraction is 30% in T54/T60 damping paint damping layer material component A. The B component of original product is added the dipropylene glycol that massfraction is 10%; Add the water-ground limestone powder that massfraction is 15%.
2, the preparation of aluminium alloy unit clamp: according to the feature of tested product, adopts the method manufacture aluminium alloy unit clamp of casting, machining refine, and carries out anodized surface process. Adopt acetone that the aluminium alloy unit clamp inner cavity surface through anodic oxidation treatment is carried out oil removal treatment, adopt pressurized air that cavity internal surface is dried process.
3, the wideband of aluminium alloy unit clamp, high damping process: wideband damping glue A, B component are mixed in the temperature environment of 35 DEG C according to the mass ratio of 1:1, mechanical stirring 5min.After mixing, static 2min. The wideband damping glue A of 1.7kg, B component mixture are filled in the cavity of fixture inside. And in the temperature environment of 35 DEG C, leave standstill solidification 48h. Thus obtain the aluminium alloy unit clamp of wideband, high damping process. In the present embodiment, the wideband damping glue of perfusion accounts for about the 18% of the rear fixture total mass of perfusion.
Use the aluminium alloy unit clamp Free Modal after hammering method measurement processing, knock 20 on fixture measuring point successively, obtain 20 groups and frequently ring function, it may also be useful to time domain multiple degree of freedom modal identification method identification fixture mode, thus obtains modal damping result as shown in table 6.
Table 6 adopts the modal damping test result of the rear aluminium alloy unit clamp (35cm) of wideband damping glue process
| Mode | Frequency (Hz) | Subsidence ratio (%) 5--> |
| 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 of the aluminium alloy unit clamp (35cm) processed without wideband, high damping, 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) | Subsidence ratio (%) |
| 1 | 958 | 0.03 |
| 2 | 1321 | 0.04 |
| 3 | 1648 | 0.15 |
| 4 | 1993 | 0.17 |
Claims (4)
1. a wideband damp treating method for vibration test fixture, is characterized in that,
(1) wideband damping glue is prepared
The damping layer material of T54/T60 damping paint is carried out modification, and damping layer material comprises A, B two kinds of components, and concrete grammar is as follows:
(1) adding the fluid rubber constituents that massfraction is 10��30% in the component A of the damping layer material of T54/T60 damping paint, described fluid rubber constituents is carboxylated nbr, hydroxyl styrene-butadiene rubber(SBR) or liquid butylhydroxy rubber;
(2) in the B component of the damping layer material of T54/T60 damping paint, the polyvalent alcohol that massfraction is 2��10% is added, massfraction is the heavy matter weighting material of 15��50%, massfraction is the density adjuster of 0��3%, and described polyhydroxy reactant is glycol ether or dipropylene glycol;
(2) preparation of test fixture
(1) design according to the size of the specific requirement of vibration test and tested product, structure, mode feature and manufacture test fixture and cavity is set on fixture, the volume of cavity and the ratio of fixture cumulative volume are greater than 0.2, the cavity internal surface of test fixture is carried out oil removal treatment, and with pressurized air or warm air, the cavity internal surface after oil removing is dried process;
(2) the wideband impedance bundary of test fixture
The wideband damping glue A prepared, B component are mixed according to mass ratio 4:1��1:1 in the temperature environment of 0��40 DEG C, and fully stirred by mixture, and churning time is 1��10min, until A, B component mix, after mixing, static 1��10min, makes the bubble entrained into overflow;
(3) wideband damping glue is poured into
The A mixed, B component mixture are filled in test fixture cavity, and carry out encapsulation process after leaving standstill solidification 24��72h in the temperature environment of 0��40 DEG C, the wideband damping glue of perfusion accounts for the 10%��50% of the rear test fixture total mass of perfusion, thus obtains 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 heavy matter weighting material is barium sulfate powder or water-ground limestone powder.
3. 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.
4. 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 internal surface is the naked surface of metal or aluminium alloy anode oxide, the anodic oxidation of magnesium alloy, aluminum alloy chemically oxidation, the chemical oxidation of magnesium alloy or the passive surface of steel.
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 CN104101471A (en) | 2014-10-15 |
| CN104101471B true 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) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112765839B (en) * | 2020-12-17 | 2022-04-01 | 哈尔滨工程大学 | Design method of metal rubber component |
| CN114459716B (en) * | 2022-04-13 | 2022-07-26 | 天津航天瑞莱科技有限公司 | Multi-frequency-band vibration amplifying device with adjustable synchronous amplification |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006126125A (en) * | 2004-11-01 | 2006-05-18 | Sony Corp | Vibration tester |
| 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 |
Family Cites Families (2)
| 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 |
| CN2848517Y (en) * | 2005-12-14 | 2006-12-20 | 霍玉杰 | Vibration shaped building block and composite inner carity of ground tile mould |
-
2014
- 2014-07-08 CN CN201410323131.3A patent/CN104101471B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006126125A (en) * | 2004-11-01 | 2006-05-18 | Sony Corp | Vibration tester |
| 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 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104101471A (en) | 2014-10-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Vichit‐Vadakan et al. | Measuring permeability of rigid materials by a beam‐bending method: III, Cement Paste | |
| Bai et al. | Study on vibration alleviating properties of glass fiber reinforced polymer concrete through orthogonal tests | |
| CN104101471B (en) | The wideband damp treating method of a kind of vibration test fixture | |
| EP2839940A1 (en) | Process for producing concrete formed body | |
| Haddad et al. | Influence of moisture content on the thermal and mechanical properties and curing behavior of polymeric matrix and polymer concrete composite | |
| CN103759814A (en) | Method for multi-frequency hybrid calibration of vibration measuring sensor | |
| Zhang et al. | Preparation and damping properties of Al2O3 hollow spheres/epoxy composites encapsulating Q195 steel pipes | |
| CN104359602A (en) | Rigidity-adjustable type ship model sea load vertical bending moment measuring device | |
| CN105001594A (en) | Earthquake physical model material and model | |
| Huang et al. | Characterization and damping property of a modified polyurea material | |
| Ehsani et al. | The positive effects of power ultrasound on Portland cement pastes and mortars; a study of chemical shrinkage and mechanical performance | |
| CN106633634A (en) | Epoxy resin foam material containing perforated structure and preparation method thereof | |
| KR101276468B1 (en) | Method for durability test of cement mixed soil | |
| Xu et al. | Enhancement of strength and water resistance of macro-defect free (MDF) gypsum modified by pregelatinized starch and hydrogen silicone oil | |
| Li et al. | The microstructure evolution of cement paste modified by cationic asphalt emulsion | |
| 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 | |
| RU2553862C1 (en) | Vibration-and-noise absorbing sheet material and method of vibration-and-noise killing | |
| CN102701623A (en) | Spraying vibration pre-processing method of aggregate of resin-mineral composite material and application in preparation of composite material | |
| CN102745927B (en) | Method and application for pressure impregnation pretreatment of aggregate of resin mineral composite | |
| CN205538528U (en) | Multi -functional ultrasonic wave cavitation test machine | |
| RU140137U1 (en) | VIBRATING-ABSORBING SHEET MATERIAL | |
| Longlong et al. | Ultrasonic propagation characteristics and microstructure analysis of cement paste doped with cellulose ether | |
| Wang et al. | Modification of Hydrophobicity of Concrete by Nanocomposite Particles | |
| CN106950339A (en) | The assay method of sulfur content in curing agent |
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 |