Two-dimensional strain flexible high temperature fiber grating sensor based on braided structure

Abstract

The invention relates to a two-dimensional strain flexible high-temperature fiber grating sensor based on a braiding structure, belonging to the field of high-temperature environment strain detection of fiber sensing technology. The sensor comprises a rectangular high-temperature-resistant flexible substrate formed by braiding a T300 carbon fiber material, three long period fiber gratings LPFG1, LPFG2 and LPFG3 are braided in the substrate, the long period fiber gratings are connected via fibers, and the intrinsic wavelengths of the long period fiber gratings are different. The LPFG1 and LPFG3 are braided in the vertical direction, the LPFG2 is braided in the horizontal direction, and temperature compensation is realized. The flexible high-temperature fiber grating sensor is characterized by comprising the flexible braided substrate, resisting the high temperature of 300 DEG C and being capable of temperature compensation,; the sensor has the advantages of being intrinsically safe, resistant to electromagnetic interference and convenient to form the distributed sensing network; and the sensor is suitable for two-dimension strain detection for surface of complex high-temperature members, and extremely excellent in high-temperature performance.

Description

technical field [0001] The invention belongs to the field of high-temperature environment strain detection of optical fiber sensing technology, and in particular relates to a two-dimensional strain flexible high-temperature optical fiber grating sensor based on a braided structure. Background technique [0002] In modern society, many places need to use strain sensors to measure the strain on the surface of the material structure, so as to detect and monitor the material structure in real time, and prevent safety accidents of the material structure, such as: high-temperature pressure pipeline leakage and pipe burst accidents, these The accident is caused by high temperature or fatigue failure of the vessel wall. The external effect is the strain change on the vessel surface. The strain is a nonlinear process. If real-time failure monitoring data of high-temperature pressure pipelines and vessels can be provided, accidents can be effectively avoided. Therefore It is of great ...

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Problems solved by technology

[0007] The purpose of the present invention is to solve the problem that the strain sensor made based on FBG cannot be applied to a high temperature environment above 200°C, cannot be better fitted on the surface of an uneven component, and cannot perform two-dimensional strain detection, and provides a strain sensor based on a braided structure. LPFG sensor for two-dimensional strain detection. At the same time, the device has the characteristics of flexibility, high temperature resistance of 300°C and temperature compensation function, which can be better attached to the surface of the component. It is especially suitable for the health detection of the surface structure of uneven high-temperature components such as high-temperature pressure pipes.

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