Design And Performance Research Of Optical Fiber F-P Sensor For Static Ice Pressure Detection

Static ice pressure is the main control load of hydraulic structures,and it is the main basis for detecting the mechanical strength and variation rule of ice.It is important to detect the ice pressure in real-time and effective,obtain the change of static ice pressure during the process of ice generation and temperature change.Compared with the traditional method of electrical measurement,fiber optic sensor has advantages of compact structure,light weight,high insulation,strong anti-interference ability,multi point detection,no electricity and long distance monitoring,it can be used in harsh environment.It is very suitable for automatic,continuous and real-time observation of static pressure.Two optical fiber F-P structures based on the same external diameter and single mode fiber and glass tube are presented.They are optical fiber single ended hollow micro-bubble structure was fabricated by gas expansion assisted technology and fiber-glass tube-fiber optical fiber structure was fabricated by high-precision optical fiber cutting platform technology.The deformation caused by the expansion of ice volume is introduced.The change of the ice pressure is detected by the multi-channel static analysis system demodulating the displacement of the center wavelength of the reflection spectrum of the sensor.In order to obtain accurate and effective data,the Fiber Bragg Grating sensor is used as the static calibration first,the relationship between the location of the position of the Fiber Bragg Grating and the center wavelength of the reflection peak of the Fiber Bragg Grating is obtained by the calibration experiment.In this paper,a metal tube /PDMS/ AB glue combination method is used to encapsulate the sensor.By tracking the peak wavelength of the interference spectrum can be conveniently measured.From the experimental results,it can be concluded that the Fiber Bragg Grating hasthe greatest compression strain at-7 ?,and the relationship between strain and center wavelength can be obtained by grating strain calibration experiment.However,because ice strain is a complex process,the change of strain is not necessarily linear.The experiment shows that the structure has a good prospect in the static ice pressure detection.