A High Precision Fiber Bragg Grating Deformation Sensor Based on Curved Triangle

Abstract

The invention discloses a high-precision fiber grating deformation sensor based on a curved side triangle. The high-precision fiber grating deformation sensor comprises a closed stainless steel outer cylinder, a triangular copper plate (1), a vertical metal rod (2) and a transverse metal rod (3), wherein the triangular copper plate (1) is in the shape of an isosceles triangle, the triangular copper plate (1) is arranged at the center of the upper part inside the stainless steel outer cylinder in an inverted manner, the upper end of the vertical metal rod (2) is fixedly connected with a vertex angle at the lower part of the triangular copper plate (1), the lower end of the vertical metal rod (2) is connected with the internal end of the transverse metal rod (3), the external end of the transverse metal rod (3) is fixed to the inner wall of the stainless steel outer cylinder, a strain slot is formed in the vertex angle at the lower part of the triangular copper plate (1) along a central direction and the vertical direction, a strain fiber Bragg grating (FBG2) is installed in the strain slot, a temperature slot is formed in the bottom side at the upper part of the triangular copper plate (1) above the strain slot, and a strained fiber Bragg grating (FBG1) is installed in the temperature slot. The high-precision fiber grating deformation sensor is not susceptible to electromagnetic interference, is high in lightning resistance, and is easy to eliminate zero drift, thereby being suitable for monitoring crustal stress-strain signals.

Description

technical field [0001] The invention relates to the field of sensors and seismic observation, in particular to a high-precision optical fiber grating deformation sensor based on curved triangles. Background technique [0002] Huge destructive earthquakes are often accompanied by property losses and casualties, so the monitoring of earthquakes is of great significance. The internal tectonic movement of the earth's crust and its surface deformation are closely related to the action of in-situ stress, and changes in the state of in-situ stress are the root causes of faults, earthquakes, folds and other geological disasters, so the monitoring of in-situ strain is of great significance. The observational data of earth strain include the deformation of the earth's crust, the change of the earth's stress field, the influence of the solid tide of the sun and the moon, and the precursor information of the earthquake. It plays an important role and is an important way for us to under...

AI Technical Summary

Problems solved by technology

[0004] At present, the drilling strain instruments mainly include liquid level volumetric, hydraulic volumetric, all-solid volumetric, capacitive, etc. Most of these strain gauges use electrical sensors, which can better monitor the state changes of crustal stress and strain. Electrical measurement methods have problems such as susceptibility to electromagnetic interference, weak anti-lightning ability, and difficult to remove zero point drift, which limit the development of fine-grained geostress detection technology

Images