Deformation quasi-distributed fiber optic sensing system in geotechnical centrifuge model body

Abstract

The invention discloses a deformation quasi-distributed fiber optic sensing system in a geotechnical centrifuge model body. The deformation quasi-distributed fiber optic sensing system comprises an optical fiber grating sensing optical cable, an optical source input and optical fiber grating demodulator, a wireless transmission device, a geotechnical centrifuge model, a centrifuge, a communication optical cable and a computer terminal, wherein the optical fiber grating sensing optical cable is directly embedded in a corresponding position in the model body according to experiment design, and is connected with the communication optical cable fixed in a rotating arm of the centrifuge; the communication optical cable is connected with the optical fiber grating demodulator fixed in an instrument bin on the centrifuge; when the centrifuge is operated at high speed, the optical fiber grating sensing optical cable and the geotechnical centrifuge model perform coordination deformation, so that the central wavelength of a optical fiber grating sensing point on the sensing optical cable is modulated; optical wavelength signals of the optical fiber grating sensing optical cable is transmitted to the demodulator through the communication optical cable, and are converted into axial strain of the optical fiber grating sensing optical cable; the wireless transmission device transmits signals. The deformation quasi-distributed fiber optic sensing system realizes real-time and quasi-distributed sensing of the interior of the model during centrifugal modeling test.

Description

1. Technical field [0001] The invention relates to a quasi-distributed in-body deformation sensing system and sensing method of a geotechnical centrifuge based on fiber grating sensing technology. Through the fiber grating sensing optical cable buried inside the model and a series of transmission and modulation and demodulation technologies, It is used for sensing the internal deformation of the centrifugal geotechnical model, and realizes quickly and comprehensively grasping the deformation state inside the geotechnical model during the model test process, and belongs to the technical field of geotechnical engineering. 2. Background technology [0002] Geotechnical centrifugal model test is to use the centrifugal force of the centrifuge to simulate the gravity, so that the stress state of the model body is consistent with the prototype, so as to study the testing technology of related engineering properties. At present, this technical means has been widely used in various f...

AI Technical Summary

Problems solved by technology

In the current geotechnical centrifugal model test, there are quite mature observation methods for the change of the external shape of the geotechnical model, but in the process of the centrifugal model test, there are relatively few methods for observing the internal deformation of the geotechnical model

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