System and method for measuring material strain by using fiber bragg grating

Abstract

The embodiment of the invention provides a system and a method for measuring material strain by using a fiber bragg grating. The system comprises a refrigeration device, a cover body, a test bench, a fiber bragg grating strain sensor, a fiber bragg grating temperature sensor and a fiber bragg grating demodulator, the cover body covers the outer sides of the refrigeration device and the test bench, the test bench is arranged on a cold head of the refrigeration device, and a fiber narrow slit for placing the fiber bragg grating temperature sensor is arranged in the test bench. And the fiber bragg grating demodulator is respectively used for collecting the fiber reflection wavelengths of the fiber bragg grating strain sensor and the fiber bragg grating temperature sensor under the temperature change. By adopting the measuring method, the heating and cooling rate of the to-be-measured material can be controlled, the problem that the fiber grating excessively depends on a low-temperature liquid cold source when measuring the strain of the material at low temperature in the prior art can be solved, the experimental operation is simplified, and the problem that a large amount of low-temperature liquid raw materials are wasted is avoided.

Description

technical field [0001] The invention relates to the field of optical fiber grating application technology, in particular to a system and a measurement method for measuring material strain by using an optical fiber grating. Background technique [0002] Fiber Bragg sensor is a functional fiber optic sensor using Fiber Bragg Grating (abbreviation: FBG) as a sensitive element. When the temperature or stress of the environment where the grating is located changes, it will cause changes in the period of the grating and the refractive index of the fiber core, so that the fiber Bragg The central wavelength of the grating fluctuates, and by detecting the Bragg wavelength shift, the temperature and stress changes of the material to be tested can be obtained. Due to the characteristics of small size, high accuracy, and anti-electromagnetic interference, fiber optic Bragg sensors are used in superconducting magnets to monitor the structural state of the system in real time. [0003] H...

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Problems solved by technology

[0004] Embodiments of the present invention provide a system and a measurement method for measuring material strain using fiber gratings, which are used to solve the uncontrollable temperature rise and fall rate of the environment caused by excessive reliance on low-temperature liquid cold sources in the prior art, and the experimental operation is complicated, resulting in low-temperature liquid The defect of a large waste of raw materials

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