Optical Fiber Monitoring Technology On Actuator Structural Load And Torsional Deformation

The structure of aerospace spacecraft affected by various factors in long time working,there are a variety of flight safety problems.The normal operation of landing gear doors and other structures is of great significance to the flight safety of aircraft,and the ability of the door retraction actuator and the load strength of the door structure are two aspects to ensure the normal operation of aircraft doors.For this reason,this paper proposes a method based on fiber Bragg grating sensor for actuator pull plate load identification and rod torsion deformation monitoring,which can be used to monitor and evaluate the real-time service status of actuator structure,and provide a reference for the health monitoring of the whole cabin door structure,so as to ensure the safety of aircraft in service.The main research contents of this paper include the following aspects:Firstly,the finite element model of the actuator pull-plate sample is established,and the surface path of the actuator pull-plate is selected to carry out the finite element analysis of the strain response under typical load.Based on the analytical solution,the decoupling method of the actuator tension plate structure under the action of tension,pressure,bending and torsion load is presented.Secondly,the working mechanism of fiber Bragg grating strain sensor is given,and the load calibration method of actuator pull plate based on fiber optic sensor is studied.Based on the finite element simulation results,the layout of fiber optic sensor is designed and the calibration equation of bending load is obtained.In this paper,the ground stage loading experiment is carried out to calibrate the tension plate load of the actuator,and the tension plate load equation of the actuator is obtained.Thirdly,the curvature recursion method and spatial coordinate transformation algorithm for the shape identification of actuator-oriented linkage structure are studied.The finite element simulation verifies the feasibility of the morphological inversion method.On the basis of this,a curvature correction algorithm is proposed for the rotation/torsional deformation of the connecting rod,and the feasibility of the method is verified by finite element simulation.Finally,a monitoring system for the deformation of connecting rod structure based on fiber Bragg grating sensor is built,and a visualization program for the deformation of structure based on Lab VIEW graphics software is developed.By comparing the deformation obtained from the inversion of the linkage structure with the measured deformation,it is verified that the curvature correction algorithm can effectively improve the inversion accuracy of the knob deformation state under the condition of torsional deformation.