Coaxial strain sensor filled with discontinuous media

Abstract

The invention discloses a coaxial strain sensor filled with discontinuous media. The coaxial strain sensor is provided with a coaxial inner conductor, an outer conductor, a protecting bush and a load, wherein the outer conductor, the protecting bush and the load are located outside the inner conductor. An insulation layer is filled between the inner conductor and the outer conductor and has an insulation section I and an insulation section II, wherein the dielectric constant of the insulation section I and the dielectric constant of the insulation section II are different. The coaxial strain sensor has the advantages that a coaxial cable mechanical structure is not changed, parts of the sensor can bear identical strain strength, local fracture is not prone to occurrence, and therefore great strain can be monitored. The seal state of an original coaxial cable is not broken, corrosion is not prone to occurrence, and the sensor can be used in a moisture environment and other complicated environments for a long period of time. The sensitivity of the sensor can be set. Additionally, the sensor is simple in structure, low in cost, easy to machine, produce and apply, high in reliability, and capable of being used for structural safety monitoring of coast dams, large hydropower stations, bridge tunnels, oil transportation and gas transportation pipelines, large stadiums and other large infrastructure.

Description

technical field [0001] The invention relates to a strain sensor with a discontinuous medium and a manufacturing method thereof. Involved patent classification number: G01 Measurement; Test, G01G Weighing, G01G3 / 00 Weighing instruments characterized by the application of elements that can produce elastic deformation, such as spring balances, G01G3 / 12 where the weighing part is under pressure or when weighing The solid form of tension, G01G3 / 14 measures the change in electrical resistance. Background technique [0002] The traditional resistance strain gauge measurement method cannot realize non-contact measurement in industrial occasions, cannot realize the internal strain measurement of the structure, cannot perform 3D strain measurement, cannot realize the distributed measurement of non-uniform strain, and is easily affected by electromagnetic interference, corrosion resistance weak. When the fiber grating sensor measures large strain, due to the restriction of the mechan...

AI Technical Summary

Problems solved by technology

Therefore, the FBG large strain sensor has the disadvantages of complex structure, fragile, and difficult to bend. At the same time, the large bend will also affect the transmission of optical signals, so its application in some extreme environments is limited.

[0003] In 2006, U.S. Patent US 20060086197 A1 introduced the coaxial cable with good signal transmission ability into the field of sensor design. The outer conductor layer of the coaxial cable was directly wound by manual spiral winding of the metal sheet outside the insulation layer of the coaxial cable. Improvement, the adjacent wound metal sheets are close together, when the structure is strained, the adjacent metal sheets are pulled apart, resulting in a change in the impedance of the coaxial cable and then reflecting the strain information, the sensitivity of the sensor and the strain measurement range It has been improved, but because it uses manual spiral winding to make the outer conductor layer of the coaxial cable sensor, there are poor contact of the wound metal sheet, large medium interference, and large signal attenuation, resulting in short effective test distance, difficult anti-corrosion treatment, and difficulty in laying out the project. Due to problems such as damage, it is impossible to realize industrial production and popularization and application of actual projects.

The preparation method of the electric grid is to drill a periodic array of holes on the skin, outer conductor and insulating layer of the coaxial line. This method also destroys the closed structure of the transmission line, which will inevitably cause leakage waves. The loss caused by leakage waves is not conducive to long-distance and large-strain Monitoring, the damage to the skin, outer conductor and insulation layer of the coaxial line during the processing reduces the anti-corrosion and moisture-proof ability of the sensor, which is not conducive to the long-term application of the sensor, and the local mechanical strength at the opening position is reduced

Another way to prepare the electric grid is to locally extrude and deform the outside of the coaxial line. Due to the extrusion deformation, the phenomenon that the mechanical strength of the electric grid is reduced has not been substantially improved.

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