Research On Deformation,Impact And Vibration Of Flexible Structure Based On Distributed Optical Fiber

In the structure health monitoring of Aeronautics and Astronautics,deformation,impact,vibration monitoring and control are the foundation of research.The spacecraft is caused failure by the surrounding complex environment in the long term space operation,causing failure.Therefore,deformation,impact and vibration are monitored accurate and timely which are also an important guarantee for ensuring the safe operation of the spacecraft.So,3D deformation monitoring and reconstruction of flexible rod structure are used distributed optical fiber sensing technology in this paper.flexible composite impact positioning and vibration test structure,and the vibration frequency of the wing model test,mainly includes the following aspects:First,a three-dimensional sensing method for three-dimensional deformation of flexible rod is studied structures based on based on the theory of spatial coordinate transformation and the deformation characteristics of flexible rod structure.Which realizes three-dimens ional deformation and reconstruction of flexible rod structures.On this basis,a 3D deformation monitoring software module of flexible rod structure based on LabVIEW is designed to realize real-time online display of flexible rod structure deformation.Secondly,in view of the low sampling frequency of FBG demodulator,the sampling rate of FBG sensor is improved by increasing sampling method.And the characteristic of fiber impact response of single s ide clamped flexible composite structure is extracted by Teager energy operator.On this basis,a method based on the time difference two points principle is put forward to achieve the impact location and coordinate location for the single side clamped flexible composite structure.Thirdly,the distributed f iber Bragg grating sensor(FBG)is used to construct the vibration monitoring system for the flexible composite structure,and the vibration characteristics of the flexible deployable structure are tested.Finally,a vibration monitoring and testing system based on Fiber Bragg grating sensor wing structure is built.The natural frequency of the wing model structure is measured,which is consistent with the measured result of the piezoelectric acceleration sensor.It verifies the practicability of FBG sensor in vibration testing.