Performance Analysis And Application Research Of High Reliability Fiber Bragg Grating Sensor

Fiber Bragg Grating sensors are widely used in various fields because of their unique advantages.In order to accomplish long-term monitoring tasks,the reliability of the sensor itself is particularly important.Sensor performance is very different due to many factors such as design scheme,process flow,and service life.In this paper,the fiber grating strain sensor is taken as the research object,several typical failure modes of this type of sensor are analyzed.Through the microscopic observation of the microscope,the sensor solder joint is determined as the key part of the strain transmission failure,resulting in the slippage of the fiber and the strain cannot be transmitted.Analyzed the influence of laser spot welding process parameters and sensor structure size on the performance and size of solder joints.Made three reasonable predictions on the shape and size of solder joints by the surface dimensions of solder joints.On this basis,the reliability of the sensor is analyzed.The sensor is used to monitor the strain of the portal crane to further reflect the reliability of the sensor.The main research works are as follows:(1)By consulting a large number of relevant literatures,we can find out the multiple failure modes of the sensor,and based on a variety of failure modes,microscopic observation of the corresponding parts of multiple fiber Bragg grating sensors to determine the main failure mode of the fiber grating sensor is solder joint defect.(2)Analyzing the influence factors of solder joint quality and structure size by studying the laser spot welding process and the structure size of the sensor.Using the microscope to measure the surface dimensions of the solder joints,three reasonable predictions were made on the shape and size of the solder joints.(3)The combination of finite element method and experimental method is proposed to analyze sensor performance.Using the finite element method,the simulation analysis of three kinds of solder joint type sensors.For the sensor that meets the design requirements,the reliability is further verified by experiments to determine the type of solder joint of the high reliability FBG sensor.This can provide a basis for sensor selection.(4)Applying the fiber grating strain sensor to monitor the long-term strain of the portal crane under various working conditions,and analyze whether the strain change corresponds to the specific working conditions,and finally confirm the reliability of the sensor.At the same time ensure the safety of the crane in long-term work.