CN111322952B - A high-sensitivity intelligent hoop for monitoring high-strength bolt looseness - Google Patents
A high-sensitivity intelligent hoop for monitoring high-strength bolt looseness Download PDFInfo
- Publication number
- CN111322952B CN111322952B CN202010164339.0A CN202010164339A CN111322952B CN 111322952 B CN111322952 B CN 111322952B CN 202010164339 A CN202010164339 A CN 202010164339A CN 111322952 B CN111322952 B CN 111322952B
- Authority
- CN
- China
- Prior art keywords
- strength bolt
- regular hexagonal
- hexagonal prism
- hoop
- prism sleeve
- 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
- 238000012544 monitoring process Methods 0.000 title claims abstract description 34
- 239000002184 metal Substances 0.000 claims abstract description 39
- 229910052751 metal Inorganic materials 0.000 claims abstract description 39
- 239000013307 optical fiber Substances 0.000 claims abstract description 32
- 238000001228 spectrum Methods 0.000 claims abstract description 7
- 230000003287 optical effect Effects 0.000 claims abstract description 6
- 230000008859 change Effects 0.000 claims abstract description 4
- 230000035945 sensitivity Effects 0.000 claims description 5
- 230000003595 spectral effect Effects 0.000 claims description 5
- 238000003466 welding Methods 0.000 claims description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 3
- 239000003822 epoxy resin Substances 0.000 claims description 3
- 229920000647 polyepoxide Polymers 0.000 claims description 3
- 229910001220 stainless steel Inorganic materials 0.000 claims description 3
- 239000010935 stainless steel Substances 0.000 claims description 3
- 230000001681 protective effect Effects 0.000 claims description 2
- 230000036541 health Effects 0.000 abstract description 5
- 238000005516 engineering process Methods 0.000 abstract description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- 230000009467 reduction Effects 0.000 abstract description 2
- 238000000034 method Methods 0.000 description 7
- 229910000831 Steel Inorganic materials 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000012806 monitoring device Methods 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 1
- 238000010009 beating Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 239000013013 elastic material Substances 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 238000011155 quantitative monitoring Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
- G01B11/18—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge using photoelastic elements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/26—Measuring arrangements characterised by the use of optical techniques for measuring angles or tapers; for testing the alignment of axes
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
Abstract
The invention provides a high-sensitivity intelligent hoop for monitoring looseness of a high-strength bolt, and belongs to the technical field of structural health monitoring. The high-sensitivity intelligent hoop for monitoring the looseness of the high-strength bolt comprises a regular hexagonal prism sleeve, an annular metal hoop, a continuous optical fiber and a protection hose. The device is based on the distributed optical fiber strain sensing technology and the principle that the looseness of the bolt can cause the optical fiber strain change, when the strain is changed, the back Rayleigh scattering spectrum of an optical signal in the optical fiber can deviate in frequency, the deviation value of the back Rayleigh scattering spectrum is in direct proportion to the change value of the strain, the real-time, quantitative and nondestructive monitoring of the looseness of the high-strength bolt is realized by monitoring the frequency shift value of the back Rayleigh scattering spectrum of the optical signal, so that the timely early warning of the looseness damage of the high-strength bolt is realized, and the safety of the structure is ensured. The invention has the advantages of simple manufacture, low economic cost, great reduction of manual work load, easy disassembly, strong applicability and convenient large-scale application.
Description
Technical Field
The invention relates to a high-sensitivity intelligent hoop for monitoring high-strength bolt looseness of an engineering structure, belongs to the technical field of structural health monitoring, and particularly relates to a high-sensitivity intelligent hoop for monitoring high-strength bolt looseness.
Background
The steel structure has the advantages of low cost, light dead weight, quick construction, energy conservation, environmental protection and the like, so that the steel structure is widely applied to civil construction and bridge engineering, and is one of the most applicable structural forms in the world. In the steel structure, common connection modes include bolt connection, weld joint connection and rivet connection, wherein high-strength bolt connection has become the most widely applied connection mode of the steel structure due to the advantages of reliable connection, convenient installation and disassembly and the like. However, in actual engineering, high-strength bolts are often loose and damaged due to factors such as temperature cyclic load, vibration, impact, corrosion and the like, so that the structure has huge potential safety hazards. The loosening of the high-strength bolts can cause the failure of key parts or the whole structure, even cause catastrophic accidents, and cause huge economic loss and casualties. Therefore, in order to timely find the high-strength bolt with potential safety hazard for replacement, the safe operation and the health state of the structure are ensured, and the high-strength bolt is monitored and warned very necessarily.
At present, common monitoring methods for high-strength bolt loosening can be divided into a visual method and a sound beating method. Wherein, the visual method is to visually observe whether the metal part changes color or other changes; the sound striking method is to strike the metal connection part with a hammer to determine whether there is slack or other abnormality from sound. However, both methods have the defects of high labor cost, incapability of long-term real-time monitoring and the like, and have strong dependence on technical experience, attitude, responsibility and the like of staff. In addition, at present, the methods of vibration analysis, acoustic emission signal analysis, piezoresistance theory and the like, which are researched by students around bolt loosening monitoring at home and abroad, are limited by various aspects of installation conditions, site environment and the like, and are difficult to apply in a large range in actual engineering at present.
In recent years, optical fibers are highly valued in structural health monitoring because of the advantages of compactness, portability, corrosion resistance, electromagnetic interference resistance, real-time monitoring, networking, reliable data and the like. The distributed optical fiber sensing technology takes an optical fiber as a sensing element, and utilizes a backscattering signal to sense physical information based on the functional relation between the backscattering signal spectrum information of an optical signal and the external physical quantity to be measured.
Therefore, aiming at monitoring the looseness of the high-strength bolt in the engineering structure, the high-sensitivity, real-time and nondestructive monitoring device is particularly important from a new technical perspective, so that an important guarantee is provided for the safe service of the engineering structure.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide the high-sensitivity intelligent hoop for monitoring the looseness of the high-strength bolt, which aims to realize the real-time monitoring of the looseness of the high-strength bolt, accurately judge the health state of the structure and further ensure the safety of the structure.
The technical scheme of the invention is as follows:
A high-sensitivity intelligent hoop for monitoring high-strength bolt loosening comprises a regular hexagonal prism sleeve 1, an annular metal hoop 2, a continuous optical fiber 3 and a protection hose 4;
the annular metal hoop 2 is sleeved on the outer side of the regular hexagonal prism sleeve 1, and six edges of the regular hexagonal prism sleeve 1 are fixed with the inner surface of the annular metal hoop 2 through welding;
The continuous optical fiber 3 surrounds the regular hexagonal prism sleeve 1 for one circle and is adhered and fixed on the outer side of the regular hexagonal prism sleeve 1 through epoxy resin;
the rest part of the continuous optical fiber 3 which is not adhered to the regular hexagonal prism sleeve 1 is protected by the outer sleeve of the protection hose 4.
The top and the bottom of the regular hexagonal prism sleeve 1 are open, the six surrounding side walls are rectangular elastic metal sheets, and the elastic metal sheets are made of stainless steel or copper or elastic materials.
The regular hexagonal prism sleeve 1 and the annular metal hoop 2 are concentric and coaxial, and the bottom surfaces of the regular hexagonal prism sleeve 1 and the annular metal hoop 2 are flush.
The bottom surface of the annular metal hoop 2 is used for welding connection with a bolt connecting piece structure.
The height of the regular hexagonal prism sleeve 1 is higher than that of the annular metal hoop 2.
The sizes of the regular hexagonal prism sleeve 1 and the annular metal hoop 2 are adjusted according to the size of an actual high-strength bolt to be detected (large hexagonal high-strength bolt), the side edge height of the regular hexagonal prism sleeve 1 is smaller than the side edge height of a nut of the high-strength bolt to be detected, and the side edge length of the bottom surface of the regular hexagonal prism sleeve 1 is larger than the side edge length of the nut of the high-strength bolt to be detected.
The working principle of the invention is as follows:
The high-strength bolts are divided into a large hexagon high-strength bolt and a torsion shear type high-strength bolt, and in practical engineering structure application, the large hexagon high-strength bolt is mostly adopted. The invention discloses a large hexagonal high-strength bolt loosening monitoring device, which is designed aiming at the loosening monitoring of a large hexagonal high-strength bolt, wherein the high-strength bolt is loosened to cause the high-strength bolt to rotate, and the high-strength bolt rotates to cause the side wall elastic metal sheet of a regular hexagonal prism sleeve to deform, so that the optical fiber adhered to the outer side of the elastic metal sheet is caused to stretch and deform. Analyzing the single side wall elastic metal sheet of the regular hexagonal prism sleeve, wherein the rotation angle of the high-strength bolt is theta, the width of the single side wall elastic metal sheet is l, the length of the corresponding optical fiber stuck on the outer side of the single side wall elastic metal sheet is l, and the length of the optical fiber after elongation deformation is l'.
The bottom surface of the nut of the large-hexagon high-strength bolt is regular hexagon, the bottom surface of the regular hexagonal prism sleeve is also regular hexagon (namely OA=OC=AC=l), the regular hexagonal prism sleeve is sleeved on the nut, the gap between the regular hexagonal prism sleeve and the nut is very small (namely OA approximately OB), the monitoring principle is shown in figure 5, according to the cosine theorem,
Each length l' of the elongated optical fiber is
Elongation of each length of optical fiber is shown as delta l
The strain epsilon of each section of optical fiber is
Based on the Rayleigh scattering distributed optical fiber strain sensing principle, when the strain changes, the back Rayleigh scattering spectrum of the optical signal in the optical fiber shifts in frequency, and the size of the shift is in direct proportion to the change of the strain, namely
v′＝v0+C·ε(6)
Wherein v 0 and v' are the spectral shifts when no strain and when strain are present, respectively; c is the strain coefficient (dv/dε); epsilon is the strain.
Substituting the relation (5) into the relation (6) to obtain the relation of the spectral frequency shift and the rotation angle theta of the high-strength bolt, namely
Therefore, the rotation angle theta of the high-strength bolt can be obtained through the spectral frequency shift measured by the continuous optical fiber and according to the relation (7).
Therefore, based on the principle of the invention, the high-strength bolt looseness and the rotation angle theta can be calculated through the spectral frequency shift measured by the continuous optical fiber.
Compared with the prior art, the invention has the following beneficial effects:
(1) According to the invention, the quantitative monitoring of the looseness of the high-strength bolt is realized by monitoring the frequency shift of the back Rayleigh scattering spectrum of the optical signal.
(2) The invention is sensitive to the micro rotation of the high-strength bolt, and has high sensitivity and stable performance.
(3) The invention can monitor the loosening condition of the high-strength bolt in real time on line and in a nondestructive way, thereby carrying out early warning maintenance on the structural safety.
(4) According to the invention, no grating is needed to be embedded, physical information of any point on the continuous optical fiber can be obtained through single measurement, and the resolution ratio is very high.
(5) The invention has the advantages of simple manufacture, low economic cost, great reduction of manual work load, easy disassembly, strong applicability and convenient large-scale application.
Drawings
FIG. 1 is a schematic diagram of a high sensitivity intelligent cuff for monitoring high strength bolt loosening in accordance with the present invention;
FIG. 2 is a cross-sectional view of A-A of the smart ferrule of the present invention for detecting high strength bolt loosening;
FIG. 3 is a cross-sectional B-B view of a high sensitivity intelligent cuff for monitoring high strength bolt loosening in accordance with the present invention;
FIG. 4 is a schematic illustration of one placement of the present invention for actual high strength bolt looseness monitoring;
fig. 5 is a schematic diagram of the monitoring principle of the present invention.
In the figure: 1, a regular hexagonal prism sleeve; 2 an annular metal hoop; 3, continuous optical fiber; 4, protecting the hose; 5, a high-sensitivity intelligent hoop for monitoring looseness of the high-strength bolt; 6, nuts of high-strength bolts; 7 bolt connection structure.
Detailed Description
In order to make the objects, features and advantages of the present invention more comprehensible, the technical solutions in the embodiments of the present invention are described in detail below with reference to the accompanying drawings, and it is apparent that the embodiments described below are only some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
As shown in fig. 1 to 5, the high-sensitivity intelligent hoop for monitoring the looseness of a high-strength bolt provided by the invention comprises a regular hexagonal prism sleeve 1, an annular metal hoop 2, a continuous optical fiber 3 and a protection hose 4;
the annular metal hoop 2 is sleeved on the outer side of the regular hexagonal prism sleeve 1, and six edges of the regular hexagonal prism sleeve 1 are fixed with the annular metal hoop 2 through welding;
The continuous optical fiber 3 surrounds the regular hexagonal prism sleeve 1 for one circle and is adhered and fixed on the outer side of the regular hexagonal prism sleeve 1 through epoxy resin;
the rest part of the continuous optical fiber 3 which is not adhered to the regular hexagonal prism sleeve 1 is sheathed and protected by a protective hose 4;
the top and the bottom of the regular hexagonal prism sleeve 1 are open, the six surrounding side walls are rectangular elastic metal sheets, and the elastic metal sheets can be stainless steel, copper and the like;
The regular hexagonal prism sleeve 1 and the annular metal hoop 2 are concentric and coaxial, and the bottom surfaces of the regular hexagonal prism sleeve 1 and the annular metal hoop 2 are level;
The bottom surface of the annular metal hoop 2 is used for welding connection with a bolt connecting piece structure;
the height of the regular hexagonal prism sleeve 1 is higher than that of the annular metal hoop 2;
the sizes of the regular hexagonal prism sleeve 1 and the annular metal hoop 2 can be adjusted according to the size of the large hexagon head high-strength bolt of the high-strength bolt to be detected actually, the side edge height of the regular hexagonal prism sleeve 1 is slightly smaller than the side edge height of the nut of the high-strength bolt to be detected, and the side length of the bottom surface of the regular hexagonal prism sleeve 1 is slightly larger than the side length of the bottom surface of the nut of the high-strength bolt to be detected.
The above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (7)
1. The high-sensitivity intelligent hoop for monitoring the looseness of the high-strength bolt is characterized by comprising a regular hexagonal prism sleeve (1), an annular metal hoop (2), a continuous optical fiber (3) and a protection hose (4);
the annular metal hoop (2) is sleeved on the outer side of the regular hexagonal prism sleeve (1), and six edges of the regular hexagonal prism sleeve (1) are fixed with the inner surface of the annular metal hoop (2) through welding; the bottom surface of the annular metal hoop (2) is used for being welded with the bolt connecting piece structure;
The continuous optical fiber (3) surrounds the regular hexagonal prism sleeve (1) for one circle and is adhered and fixed on the outer side of the regular hexagonal prism sleeve (1) through epoxy resin;
the rest part of the continuous optical fiber (3) which is not adhered to the regular hexagonal prism sleeve (1) is sheathed and protected by a protective hose (4);
The high-strength bolt loosens to cause the high-strength bolt to rotate, and the high-strength bolt rotates to cause the side wall elastic metal sheet of the regular hexagonal prism sleeve (1) to deform, so that the optical fiber stuck on the outer side of the elastic metal sheet is caused to elongate and deform;
Based on the Rayleigh scattering distributed optical fiber strain sensing principle, when the strain is changed, the back Rayleigh scattering spectrum of an optical signal in the optical fiber shifts in frequency, and the size of the shift is in direct proportion to the change of the strain;
The rotation angle of the high-strength bolt can be obtained through the spectral frequency shift measured by the continuous optical fiber.
2. The intelligent high-sensitivity hoop for detecting high-strength bolt looseness according to claim 1, wherein the top and bottom of the regular hexagonal prism sleeve (1) are open, the surrounding six side walls are rectangular elastic metal sheets, and the elastic metal sheets are stainless steel or copper.
3. The high-sensitivity intelligent hoop for monitoring high-strength bolt looseness according to claim 1 or 2, wherein the regular hexagonal prism sleeve (1) and the annular hoop (2) are concentric and coaxial, and the bottom surfaces of the regular hexagonal prism sleeve (1) and the annular hoop (2) are flush.
4. The smart high sensitivity ferrule for monitoring high-strength bolt looseness according to claim 1 or 2, wherein the height of the regular hexagonal prism sleeve (1) is higher than the height of the annular ferrule (2).
5. A smart high sensitivity ferrule for monitoring high strength bolt looseness according to claim 3, wherein the height of the regular hexagonal prism sleeve (1) is higher than the height of the annular ferrule (2).
6. The high-sensitivity intelligent hoop for monitoring high-strength bolt looseness according to claim 1,2 or 5, wherein the sizes of the regular hexagonal prism sleeve (1) and the annular metal hoop (2) are adjusted according to the size of the high-strength bolt to be detected actually, the side edge height of the regular hexagonal prism sleeve (1) is smaller than the side edge height of a nut of the high-strength bolt to be detected, and the bottom side edge length of the regular hexagonal prism sleeve (1) is larger than the bottom side edge length of the nut of the high-strength bolt to be detected.
7. The intelligent high-sensitivity hoop for monitoring looseness of a high-strength bolt according to claim 3, wherein the sizes of the regular hexagonal prism sleeve (1) and the annular metal hoop (2) are adjusted according to the size of the high-strength bolt to be detected actually, the side edge height of the regular hexagonal prism sleeve (1) is smaller than the side edge height of a nut of the high-strength bolt to be detected, and the side edge length of the bottom surface of the regular hexagonal prism sleeve (1) is larger than the side edge length of the nut of the high-strength bolt to be detected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010164339.0A CN111322952B (en) | 2020-03-11 | 2020-03-11 | A high-sensitivity intelligent hoop for monitoring high-strength bolt looseness |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010164339.0A CN111322952B (en) | 2020-03-11 | 2020-03-11 | A high-sensitivity intelligent hoop for monitoring high-strength bolt looseness |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111322952A CN111322952A (en) | 2020-06-23 |
| CN111322952B true CN111322952B (en) | 2024-06-14 |
Family
ID=71165711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010164339.0A Active CN111322952B (en) | 2020-03-11 | 2020-03-11 | A high-sensitivity intelligent hoop for monitoring high-strength bolt looseness |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111322952B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN211477013U (en) * | 2020-03-11 | 2020-09-11 | 大连理工大学 | High-sensitivity intelligent hoop for monitoring looseness of high-strength bolt |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3740500B2 (en) * | 2002-12-25 | 2006-02-01 | 独立行政法人 宇宙航空研究開発機構 | OFDR multi-point strain measuring device |
| CN102235921B (en) * | 2011-03-29 | 2013-12-04 | 徐峻锋 | Optical fiber sensor for detecting strain and temperature change simultaneously |
| KR101325710B1 (en) * | 2012-02-15 | 2013-11-06 | 삼성중공업 주식회사 | Apparatus for monitoring loose nut of wind turbine generator |
| JP3189322U (en) * | 2013-12-24 | 2014-03-06 | 株式会社シー・エス・シー | Thermal insulation for pipe end fittings |
| CN104266786A (en) * | 2014-09-05 | 2015-01-07 | 武汉理工光科股份有限公司 | Bolt fastening degree online detecting system and method based on OTDR technology |
| US9971114B2 (en) * | 2015-11-13 | 2018-05-15 | Ofs Fitel, Llc | Optical cable containing fiber bundles and thread for tying the bundles |
| CN107152449A (en) * | 2017-06-30 | 2017-09-12 | 大连理工大学 | It is a kind of that the intelligent gasket device that monitoring bolt loosens is used for based on fiber grating |
| CN108548516A (en) * | 2018-06-28 | 2018-09-18 | 国电联合动力技术有限公司 | A kind of high-strength bolt loosens intelligent monitoring device, method and its generating set |
| CN110220682B (en) * | 2019-05-30 | 2021-11-23 | 苏州热工研究院有限公司 | Monitoring device and monitoring method for monitoring bolt looseness |
| CN110736901A (en) * | 2019-10-09 | 2020-01-31 | 河海大学 | Cable partial discharge distributed online monitoring and positioning method based on phi-OTDR principle |
-
2020
- 2020-03-11 CN CN202010164339.0A patent/CN111322952B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN211477013U (en) * | 2020-03-11 | 2020-09-11 | 大连理工大学 | High-sensitivity intelligent hoop for monitoring looseness of high-strength bolt |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111322952A (en) | 2020-06-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203130381U (en) | Tower capable of online testing bolt shaft force | |
| CN107830898B (en) | Corrosion environment monitoring device based on optical fiber sensing and monitoring method thereof | |
| CN105890834A (en) | Shield segment connecting screw bolt stress state detection method | |
| CN103940903A (en) | Truss structured node damage detecting system and method | |
| CN102564875A (en) | Steel wire rope fatigue assessment system based on five point bending test | |
| CN114396968B (en) | Bolt loosening monitoring system and method based on FBG curvature sensor | |
| CN102431918B (en) | Method for judging damage position on steel structure of tower body of tower crane | |
| CN211626767U (en) | Force measuring support convenient for replacing sensing device | |
| CN107014530B (en) | Intelligent bolt capable of simultaneously realizing self-monitoring of axial force and shearing force and method | |
| CN211477013U (en) | High-sensitivity intelligent hoop for monitoring looseness of high-strength bolt | |
| CN111322952B (en) | A high-sensitivity intelligent hoop for monitoring high-strength bolt looseness | |
| CN206469864U (en) | A kind of intelligent bolt for bridge structural health monitoring | |
| CN111075819B (en) | Color-changing bolt | |
| Tikka et al. | Strain gauge capabilities in crack detection | |
| CN113640301B (en) | Bolt detection method for special equipment | |
| CN107655610A (en) | A kind of intelligent bolt, intelligent bolt calibration system and monitoring system | |
| CN102735461A (en) | Identification method for problem cables and angular support displacement on basis of temperature variation and cable force monitoring | |
| CN206270275U (en) | A kind of bridge sling monitors sensor | |
| CN205981524U (en) | Be used for civil engineering prestressing force shearing force detection device | |
| CN205679485U (en) | A kind of for surveying the experimental rig stretching slippage under bolt connection node low temperature | |
| CN110398306B (en) | Thermal power plant pipeline stress decoupling analysis system and analysis method | |
| CN209673268U (en) | A kind of device for testing the existing stress of concrete | |
| CN103293092B (en) | A kind of carbon nano-tube pick-up unit of corrosion of concrete bar in reinforced concrete | |
| CN210570470U (en) | Concrete structure's crack dynamic monitoring device | |
| CN204758192U (en) | Bolt mounting process performance aassessment equipment |
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 |