CN206177728U - Hopkinson pressure bar test device - Google Patents
Hopkinson pressure bar test device Download PDFInfo
- Publication number
- CN206177728U CN206177728U CN201621256809.1U CN201621256809U CN206177728U CN 206177728 U CN206177728 U CN 206177728U CN 201621256809 U CN201621256809 U CN 201621256809U CN 206177728 U CN206177728 U CN 206177728U
- Authority
- CN
- China
- Prior art keywords
- bar
- load
- sample
- incident
- test device
- 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.)
- Withdrawn - After Issue
Links
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 title claims abstract description 27
- 230000005540 biological transmission Effects 0.000 claims abstract description 34
- 238000012545 processing Methods 0.000 claims abstract description 7
- 239000000523 sample Substances 0.000 claims description 67
- 239000000463 material Substances 0.000 claims description 23
- 238000013480 data collection Methods 0.000 claims description 6
- 230000001419 dependent effect Effects 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 2
- 230000006835 compression Effects 0.000 abstract description 35
- 238000007906 compression Methods 0.000 abstract description 35
- 238000012360 testing method Methods 0.000 abstract description 13
- 230000006378 damage Effects 0.000 abstract description 7
- 239000004429 Calibre Substances 0.000 abstract 1
- 238000010521 absorption reaction Methods 0.000 abstract 1
- 230000003466 anti-cipated effect Effects 0.000 abstract 1
- 238000003556 assay Methods 0.000 abstract 1
- 238000002474 experimental method Methods 0.000 description 14
- 238000007796 conventional method Methods 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 4
- 238000012669 compression test Methods 0.000 description 4
- 239000004519 grease Substances 0.000 description 4
- 230000001050 lubricating effect Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 239000002131 composite material Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000010422 painting Methods 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- 235000008331 Pinus X rigitaeda Nutrition 0.000 description 1
- 235000011613 Pinus brutia Nutrition 0.000 description 1
- 241000018646 Pinus brutia Species 0.000 description 1
- 208000037656 Respiratory Sounds Diseases 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000000805 composite resin Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
Landscapes
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The utility model belongs to the technical field of the test. Based on one -dimensional hopkinson pressure bar test device, introduce the suit and bear the impact load after the sample reaches anticipated meeting an emergency at the carrier ring between incident bar and the transmission bar, realize the accurate control of compression strain. The utility model relates to a hopkinson pressure bar test device, including emitter (1), hitting rod (2), incident bar (3), transmission bar (5), absorption pole (6) and data acquisition and processing system, set up the strain control structure of constituteing by carrier ring (8) and fixing sleeve (7) between incident bar and transmission bar, carrier ring and incident bar are the same with the transmission bar external diameter, and fixing sleeve is clearance fit with carrier ring, incident bar and transmission bar, the carrier ring suit is put at the inside central point of fixing sleeve. This test device, simple structure, convenient operation, compression strain are measured controllablely, are applicable to the dynamic mechanical capability test and the assay of destruction appearance that decide under the compression strain condition, and specially adapted heavy -calibre hopkinson pressure bar is experimental.
Description
Technical field
The utility model belongs to technical field of measurement and test, is related to material dynamic mechanical experimental technique, more particularly to Hopkinson
Depression bar tests compression strain control technology.
Background technology
In many cases, the load that material and its structure member are born in application process is Impulsive load, and big
Have significantly different under mechanical property of most materials under shock loading and quasistatic, dynamic force of the material under Impulsive load
The important mechanical property parameter that characteristic is materials application is learned, the test and analysis of mechanical property are to material under development material impact load
Material is developed and the design of part has great importance.
One-dimensional Hopkinson bar experimental rig is to carry out material dynamic mechanical performance test at present with the main experimental for characterizing
Means, typical one-dimensional Hopkinson pressure bar test schematic device such as Fig. 1.In conventional Hopkinson pressure bar test, by
The transmitting strike strike incident bar 3 of bar 2 of emitter 1, forms the incident stress wave pulse of compression in incident bar 3, and pulse propagation is extremely
The loading end of incident bar is compressed to sample 4 and compression transmission stress wave is produced in transmission bar 5, while adding in incident bar 3
Carrying end will produce a reverse tensile stress wave impulse.When back wave reaches the strike end (free end) of incident bar 3, again
Second-compressed ripple is reflected as, second-compressed loading can be carried out to sample, and circulate in this format.Due to load pulses duration very
Short, usually tens microseconds to hundreds of microseconds, whole impact compress process is loading of the compression incidence wave pulse to sample and goes through
Journey, compression moment completes.Therefore, for traditional one-dimensional Hopkinson pressure bar test device, in test cannot be to sample
Compressive strain is accurately controlled.
In material dynamic mechanical performance study, the impact compress for carrying out sample using Hopkinson pressure bar test device is tried
When testing, the result of the test for obtaining is the lower result of the test of whole load pulses effect, and the sample faulted condition after experiment be by
State after repeated loading, for the less material of failure strain amount, the sample after experiment is usually broken state.According to material
Expect the requirement of applying working condition, it is sometimes desirable in test sample compressive strain is set and controlled, is carried out research material and is existed
Mechanical property and material damage morphology analysis under specific strain amount.Accordingly, it would be desirable in traditional Hopkinson pressure bar test
Realize effectively compression strain control.
At present, the report on Hopkinson pressure bar compressive strain Control experiment technology is had no.
The content of the invention
The purpose of this utility model is to provide a kind of experimental rig of Hopkinson pressure bar compression strain control, effectively
Realize accurate control of the Hopkinson pressure bar test to sample compressive strain.
The purpose of this utility model is achieved in that, based on one-dimensional Hopkinson pressure bar test device, introducing is sleeved on
The strain control device of the periphery of sample 4 between incident bar 3 and the loading end of transmission bar 5, bears sample and reaches expection by load-carrying ring 8
Loading wave impulse after strain effectively limits subsequent load pulse and the continued compression of sample is added to the shock loading of sample 4
Carry, realize the accurate control of compression strain.
The Hopkinson pressure bar test device that the utility model is related to, including emitter 1, strike bar 2, incident bar 3, thoroughly
Penetrate bar 5, absorbing rod 6 and data Collection ＆ Processing System, it is characterised in that：Set by carrying between incident bar 3 and transmission bar 5
The strain controlling structure of ring 8 and the composition of fixes sleeve 7；Load-carrying ring 8 is identical with incident bar 3 and the external diameter of transmission bar 5, fixes sleeve 7
Gap is with load-carrying ring 8, incident bar 3 and transmission bar 5 to coordinate；Load-carrying ring 8 is sleeved on the inner hub location of fixes sleeve 7, Gu
The two ends for determining sleeve 7 are set with the loading end of incident bar 3 and transmission bar 5 respectively, and the structure after assembling is as shown in Figure 2；Load-carrying ring 8
With the intensity and elastic modelling quantity of intensity and elastic modelling quantity not less than load bar material of material；The structural parameters of load-carrying ring 8：
l1=l0(1-εL) (1)
d1>d0(1+μ·εL) (2)
Wherein：
l1It is the length of load-carrying ring；
l0It is the initial length of sample；
εLIt is the expected dependent variable of sample；
d1It is the internal diameter of load-carrying ring；；
d0It is the initial diameter of sample；
μ is the Poisson's ratio of sample material.
The Hopkinson pressure bar test device that the utility model is related to, including emitter 1, strike bar 2, incident bar 3, thoroughly
Penetrate bar 5, absorbing rod 6 and data Collection ＆ Processing System, it is characterised in that：Fixes sleeve 7 it is not small with the length difference of load-carrying ring 8
In 20mm.
The Hopkinson pressure bar test device that the utility model is related to, including emitter 1, strike bar 2, incident bar 3, thoroughly
Penetrate bar 5, absorbing rod 6 and data Collection ＆ Processing System, it is characterised in that：Fixes sleeve 7 and load-carrying ring 8, incident bar 3, transmission
Fit clearance 0.1mm~the 0.2mm of bar 5, independently of one another.
The Hopkinson pressure bar test device that the utility model is related to, including emitter, strike bar 2, incident bar 3, thoroughly
Penetrate bar 5, absorbing rod 6 and data Collection ＆ Processing System, it is characterised in that：The annular cross-sectional area of load-carrying ring 8 is not less than loading
The 1/2 of the area of section of bar.
The Hopkinson pressure bar test device that the utility model is related to, including emitter, strike bar 2, incident bar 3, thoroughly
Penetrate bar 5, absorbing rod 6 and data Collection ＆ Processing System, it is characterised in that：Load-carrying ring 8 is concentric with sample.
The experimental rig of Hopkinson pressure bar compression strain that the utility model is related to control, simple structure, it is easy to operate,
The dependent variable of compression is controllable, compressive strain precise control reliability.Suitable for dynamic mechanical of the sample under specific compression strain
Performance test and destruction morphology analysis, can obtain the dynamic forces such as stress of the sample under impact loading, strain and strain rate
Learn parameter.Back wave is asked the repeated loading of sample during the utility model can also be effectively prevented from one-dimensional Hopkinson pressure bar test
Topic；It is particularly well-suited to the dynamic mechanical carried out to sample under pulse loading environment in the experiment of heavy caliber Hopkinson pressure bar
Can characterize and analysis.
Brief description of the drawings
The one-dimensional Hopkinson pressure bar test schematic devices of Fig. 1
The Hopkinson pressure bar test device compression strain control section that Fig. 2 the utility model is related to is before Impulsive load
Assembly structure diagram
The Hopkinson pressure bar test device compression strain control section that Fig. 3 the utility model is related to is in sample compression strain
Reach structural representation during desired value
The stress wave signal curve on Φ 37mm depression bar load bars that Fig. 4 the utility model embodiment one is related to
The sample compression stress strain curve that the Φ 37mm depression bars that Fig. 5 the utility model embodiment one is related to are measured
Stress wave signal curve on Fig. 6 conventional method Φ 37mm depression bar load bars
The sample compression stress strain curve that Fig. 7 conventional method Φ 37mm depression bars are measured
The stress wave signal curve on Φ 100mm depression bar load bars that Fig. 8 the utility model embodiment two is related to
The sample compression stress strain curve that the Φ 100mm depression bars that Fig. 9 the utility model embodiment two is related to are measured
Stress wave signal curve on Figure 10 conventional method Φ 100mm depression bar load bars
The sample compression stress strain curve that Figure 11 conventional method Φ 100mm depression bars are measured
Wherein：1- emitters, 2- strike bars, 3- incident bars, 4- samples, 5- transmission bars, 6- absorbing rods, 7- fixed covers
Cylinder, 8- load-carrying rings
Specific embodiment
The utility model is further illustrated with reference to the accompanying drawings and examples.And provide Experimental Comparison with conventional equipment
Data, but not as the limitation to utility model content.
Embodiment one
By taking the compression test of Φ 37mm bore Hopkinson pressure bar devices as an example, Hopkinson pressure bar test device is carried out
Describe in detail.And provide Experimental Comparison data with conventional equipment.
The a diameter of Ф 37mm of load bar, the length of incident bar 3 is 2m, and the length of transmission bar 5 is 2m, and the length of absorbing rod 6 is 1m.
The material of sample 4 is fiber-reinforced resin matrix compound material, and length is l0=12mm, diameter d0=22mm, the pool of material
Pine is than being μ=0.33.Expected compression strain value is 5%.
The length of load-carrying ring is calculated l by formula (1)1=11.4mm；External diameter：Ф 37mm, internal diameter is calculated by formula (2)
Obtain d1More than 22.36mm, it is contemplated that the deformation of composite and damage feature, internal diameter d1Take 23mm.
Fixes sleeve：Internal diameter Ф 37.15mm, external diameter Ф 47mm, length 50mm.
Behind 8 sets of loading fixes sleeve 7 centers of load-carrying ring, one end and the loading end set of incident bar 3 of fixes sleeve 7
Dress, is placed in load-carrying ring 8 and in compression is docked with the loading end face of incident bar 3 after the both ends of the surface of sample 4 are applied into lubricating grease, and sample 4 is inhaled
The loading end center of incident bar 3 is attached to, load-carrying ring 8 is equidistant with sample 4.The other end of fixes sleeve and the loading end pair of transmission bar 5
Assembling is connect, incident bar 3, sample 4 and transmission bar 5 are compressed, sample end face is fully pasted with the loading end face of incident bar 3, transmission bar 5
Close, the compression strain control device structural representation after assembling is as shown in Figure 2.
Impact compression test is carried out to sample 4 according to a conventional method, the strain when the compression strain of sample reaches desired value
Control device configuration state schematic diagram is as shown in Figure 3.Specimen configuration after experiment is remained intact substantially, and part occurs in sample side
Crackle, incident bar and transmission bar upper stress ripple signal such as Fig. 4, compression stress strain curve such as Fig. 5 of sample, have effectively achieved
Accurate control to the compressive strain of sample 5%.
Contrast groups：Percussive pressure is carried out between incident bar 3 and transmission bar 5 by being placed directly within after the both ends of the surface of sample 4 painting lubricating grease
Contracting experiment, the stress wave signal such as Fig. 6 on incident bar and transmission bar, compression stress strain curve such as Fig. 7 of sample.After experiment
Sample is compression shear broken state, and sample reaches maximal destruction strain, it is impossible to which the compressive strain to sample is controlled, sample quilt
It is loaded onto failure strain 6.3%.
Embodiment two
The present embodiment by taking the compression test of Φ 100mm heavy caliber Hopkinson pressure bar devices as an example, to Hopkinson pressure bar
Experimental rig is described in detail.
The a diameter of Ф 100mm of load bar, the length of incident bar 3 is 5m, and the length of transmission bar 5 is 5m, and the length of absorbing rod 6 is 2m.
The material of sample 4 is dimension reinforced resin based composites, and the length of sample 4 is l0=40mm, a diameter of d0=60mm, examination
The Poisson's ratio of the material of sample 4 is μ=0.33.Expected compression strain value is 1.5%.
The length of load-carrying ring is calculated l by formula (1)1=39.4mm；External diameter：Ф 100mm, internal diameter is counted by formula (2)
Calculation obtains d1More than 60.3mm, it is contemplated that the deformation of composite and damage feature, internal diameter d1Take 62mm.
Fixes sleeve：Internal diameter Ф 100.15mm, external diameter Ф 110mm, length 100mm.
After by 8 sets of loading fixes sleeve 7 centers of load-carrying ring, one end of fixes sleeve 7 is set with the loading end of bar 3 is penetrated,
It is placed in load-carrying ring 8 and in compression is docked with the loading end face of incident bar 3 after the both ends of the surface of sample 4 are applied into lubricating grease, adsorbs sample 4
In the loading end of incident bar 3, make load-carrying ring 8 equidistant with sample 4.Again by the other end of fixes sleeve and the loading end pair of transmission bar 5
Assembling is connect, incident bar 3, sample 4 and transmission bar 5 are firmly compressed, make sample end face and incident bar 3, the loading end face of transmission bar 5
Fully laminating, then the compression strain control device structural representation after assembling as shown in Fig. 2 carry out impact compression test.Examination
Specimen configuration after testing is remained intact substantially, and specimen configuration is without significant change.Answering on the incident bar and transmission bar that experiment is measured
Wave signal such as Fig. 8, compression stress strain curve such as Fig. 9 of sample.Have effectively achieved in this experiment and sample 1.5% is pressed
The accurate control of shrinkage strain amount.
Contrast groups：Percussive pressure is carried out between incident bar 3 and transmission bar 5 by being placed directly within after the both ends of the surface of sample 4 painting lubricating grease
Contracting experiment.Sample after experiment is compression shear broken state, i.e. sample and has reached maximal destruction strain, the incident bar that experiment is measured
With such as Figure 10 of the stress wave signal on transmission bar, compression stress strain curve such as Figure 11 of sample.In this test cannot be to examination
The compressive strain (1.5%) of sample is controlled, and sample is loaded on failure strain 2.5%, and sample state is broken after experiment.
Claims (6)
1. a kind of Hopkinson pressure bar test device, including emitter (1), strike bar (2), incident bar (3), transmission bar (5),
Absorbing rod (6) and data Collection ＆ Processing System, it is characterised in that：Set by carrying between incident bar (3) and transmission bar (5)
The strain controlling structure of ring (8) and fixes sleeve (7) composition；Load-carrying ring (8) is identical with incident bar (3) and transmission bar (5) external diameter,
Fixes sleeve (7) is gap cooperation with load-carrying ring (8), incident bar (3) and transmission bar (5)；Load-carrying ring (8) is sleeved on fixed cover
Cylinder (7) inner hub location, the two ends of fixes sleeve (7) are set with the loading end of incident bar (3) and transmission bar (5) respectively；Hold
Carry the intensity and elastic modelling quantity of intensity and elastic modelling quantity not less than load bar material of ring (8) material；The knot of load-carrying ring (8)
Structure parameter：
l1=l0(1-εL) (1)
d1>d0(1+μ·εL) (2)
Wherein：
l1It is the length of load-carrying ring；
l0It is the initial length of sample；
εLIt is the expected dependent variable of sample；
d1It is the internal diameter of load-carrying ring；；
d0It is the initial diameter of sample；
μ is the Poisson's ratio of sample material.
2. Hopkinson pressure bar test device according to claim 1, it is characterised in that：Fixes sleeve (7) with carrying
The length difference of ring (8) is not less than 20mm.
3. Hopkinson pressure bar test device according to claim 1, it is characterised in that：Fixes sleeve (7) and load-carrying ring
(8), the fit clearance 0.1mm~0.2mm of incident bar (3), transmission bar (5), independently of one another.
4. the Hopkinson pressure bar test device according to claims 1 to 3 any one, it is characterised in that：Load-carrying ring (8)
Annular cross-sectional area be not less than load bar area of section 1/2.
5. the Hopkinson pressure bar test device according to claims 1 to 3 any one, it is characterised in that：Load-carrying ring (8)
It is concentric with sample.
6. Hopkinson pressure bar test device according to claim 4, it is characterised in that：Load-carrying ring (8) is concentric with sample.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621256809.1U CN206177728U (en) | 2016-11-23 | 2016-11-23 | Hopkinson pressure bar test device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621256809.1U CN206177728U (en) | 2016-11-23 | 2016-11-23 | Hopkinson pressure bar test device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206177728U true CN206177728U (en) | 2017-05-17 |
Family
ID=58685738
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201621256809.1U Withdrawn - After Issue CN206177728U (en) | 2016-11-23 | 2016-11-23 | Hopkinson pressure bar test device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN206177728U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106483028A (en) * | 2016-11-23 | 2017-03-08 | 山东非金属材料研究所 | A kind of Hopkinson pressure bar test device |
| CN109708956A (en) * | 2019-01-17 | 2019-05-03 | 浙江大学 | A kind of positioning device for dynamic splitting test |
| CN110057690A (en) * | 2019-05-09 | 2019-07-26 | 福州大学 | Hopkinson bar concrete material dual shear test device and its application method |
| CN107478501B (en) * | 2017-08-16 | 2020-04-17 | 北京有色金属研究总院 | Protection device and experimental method for reflection type Hopkinson pull rod sample |
| CN116698626A (en) * | 2023-06-08 | 2023-09-05 | 华中科技大学 | Single-pulse high strain rate tensile test device based on Hopkinson pressure bar |
-
2016
- 2016-11-23 CN CN201621256809.1U patent/CN206177728U/en not_active Withdrawn - After Issue
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106483028A (en) * | 2016-11-23 | 2017-03-08 | 山东非金属材料研究所 | A kind of Hopkinson pressure bar test device |
| CN106483028B (en) * | 2016-11-23 | 2024-02-06 | 山东非金属材料研究所 | Hopkinson pressure bar test device |
| CN107478501B (en) * | 2017-08-16 | 2020-04-17 | 北京有色金属研究总院 | Protection device and experimental method for reflection type Hopkinson pull rod sample |
| CN109708956A (en) * | 2019-01-17 | 2019-05-03 | 浙江大学 | A kind of positioning device for dynamic splitting test |
| CN110057690A (en) * | 2019-05-09 | 2019-07-26 | 福州大学 | Hopkinson bar concrete material dual shear test device and its application method |
| CN116698626A (en) * | 2023-06-08 | 2023-09-05 | 华中科技大学 | Single-pulse high strain rate tensile test device based on Hopkinson pressure bar |
| CN116698626B (en) * | 2023-06-08 | 2024-05-28 | 华中科技大学 | Single-pulse high strain rate tensile test device based on Hopkinson pressure bar |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN206177728U (en) | Hopkinson pressure bar test device | |
| CN106483028A (en) | A kind of Hopkinson pressure bar test device | |
| Petit et al. | Impact and compression after impact experimental study of a composite laminate with a cork thermal shield | |
| CN104792611B (en) | Concrete compression bursting stress strain full curve test device | |
| Pankow et al. | Split Hopkinson pressure bar testing of 3D woven composites | |
| Yang et al. | Statistical Fatigue of Graphite/Epoxy Angle-Ply Laminates in Shear1 | |
| CN201387410Y (en) | Tensile impact experimental device based on Hopkinson pressure bar technique | |
| CN106950101A (en) | Rivet draws and cuts Coupled Dynamic mechanical property test fixture | |
| Wu et al. | Acoustic emission characteristics and felicity effect of wood fracture perpendicular to the grain | |
| CN109811806A (en) | A kind of whole detection method of architectural engineering | |
| CN109632472A (en) | A kind of rock sample fixture and application method suitable for true triaxial tension test | |
| CN107255598B (en) | Confining pressure device for enabling soil sample to be taken out easily in Hopkinson test | |
| CN207396214U (en) | Tensile Strength of Rock measurement device in laboratory | |
| CN107884271B (en) | Impact-pulling converter for rock dynamic direct tensile test and impact-pulling test method | |
| CN217421234U (en) | Resistance type hollow anchor rod dynamometer | |
| CN203148657U (en) | Device for detecting comprehensive mechanical properties of anchor rods | |
| Bragov et al. | Deformation and Destruction at Deformation Rate of Order 10 3 s− 1 in Wood of Hardwood Trees | |
| Zhuge et al. | Material properties and impact resistance of a new lightweight engineered cementitious composite | |
| Takahashi et al. | Deformation and strength characteristics of Kimachi sandstone under confined compression and extension test conditions | |
| Degallaix et al. | Cyclic shearing behaviour of a unidirectional glass/epoxy composite | |
| Scarponi | Impact behavior of natural fiber composite laminates | |
| Gong et al. | Dynamic empirical Mohr-Coulomb criterion of marble under low loading rate | |
| CN111143975A (en) | Calculation method for compression mechanics structure of forged carbon fiber composite material | |
| CN203643265U (en) | High-strength concrete compression test cracking-proofing device | |
| Whitcomb | Composite materials: testing and design (eighth conference) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20170517 Effective date of abandoning: 20240206 |
|
| AV01 | Patent right actively abandoned |
Granted publication date: 20170517 Effective date of abandoning: 20240206 |
|
| AV01 | Patent right actively abandoned | ||
| AV01 | Patent right actively abandoned |