Research On Optical Fiber Monitoring Method Of Statics And Dynamics Response Of Mast

Truss type mast is the main load support component of spacecraft.It is widely used in space station,deep space telescope,deployable antenna array and solar sail because of its unique advantages,such as excellent unfolding and closing performance,light weight and good stability after structure unfolding.It is of great significance important to monitor and analyze the static and dynamic response characteristics of the mast for the accurate attitude perception,control and health assessment of the space truss structure.The research content of this paper includes the following aspects.Firstly,the dynamic and static response analysis of the mast are carried out.In this paper,the static analysis of truss type mast is carried out by the node method.The stress forms of each node and the main parameters that affect the bending rigidity of the mast are given.The three-dimensional mechanical model of the mast is established,and the strain distribution and response law of the arm structure under static load are obtained by finite element simulation.The modal analysis of the support arm,the dynamic response analysis of the structure under the excitation of transient signal and simple harmonic signal are carried out.Secondly,particle swarm optimization(PSO)is proposed to optimize the shape reconstruction of the mast.The initialization parameter setting method of particle swarm optimization(PSO)and its combination with shape reconstruction optimization objective are given.Two shape reconstruction algorithms based on slope and displacement equation and structure curvature and arc length information are studied respectively.Particle swarm optimization(PSO)algorithm is used to improve the inversion accuracy of truss arm shape reconstruction under static simulation loading.Thirdly,the distributed optical fiber monitoring and inversion system of truss type mast is constructed.The corresponding layout of FBG sensor is given,and the strain response characteristics of key nodes of the support arm structure under typical static load are obtained.Particle swarm optimization is used to improve the inversion accuracy of shape of the mast reconstruction.The real-time collected strain information is substituted into the deformation inversion algorithm to realize the real-time monitoring,inversion and visual display of shape of the truss type mast.Finally,the distributed optical fiber monitoring method for dynamic response of truss type mast is studied.The natural modal response of the support arm structure is obtained by the hammering method and the sweeping frequency method.The frequency response function of the mast is obtained by combining the vibration tester and the force hammer.Combined with the shape reconstruction algorithm,the dynamic displacement inversion of the free end of truss arm structure under dynamic load is realized.