Study On Structural Mechanics Of Space Elastic Thin Plate Equipped With Precision Instruments

Throughout the history of human spaceflight,the failure of space products often occurred caused by the external environment.Because the operation of spacecraft is in the harsh space environment,the complex external excitation or its own characteristics can easily affect the performance of all kinds of vulnerable equipment in the spacecraft.Therefore,the research on the mechanical properties and vibration characteristics of the local combination structure of the electronic components in the spacecraft is the premise to ensure the stable operation and work of the spacecraft.Therefore,in this paper,the mechanical properties and vibration characteristics of the composite structure system with cylindrical electronic components are studied by combining theoretical derivation and finite element simulation.It mainly includes the following research contents:Firstly,based on the elastic plate theory,the bending theory of orthotropic circular plates in polar coordinates is introduced and derived.Then the stiffness equivalent theory of the composite structure is derived and the calculation formula of electronic component-thin plate coupling system deflection under the corresponding example is solved.These theories lay a theoretical foundation for the analysis and discussion in the following chapters.The finite element model of a circular plate coupling system with a cylindrical electronic component in the center is established.The bending tests based on two-dimensional model and three-dimensional model were designed respectively to study the migration rule and position distribution of the neutral layer of strain in the cross section of the system,which proved the deformation coordination of the system.The changes of strain neutral layer and bending stiffness at the abrupt change of structure position are analyzed.A method for calculating the equivalent bending stiffness of spatial composite structures is introduced.According to the different section shape,the composite structure is divided into different structural regions.Based on the proportional relationship between each structural area and the whole structure,the formula for calculating the equivalent bending stiffness of the system is derived.Through the design of numerical experiments,the calculation solution and finite element simulation solution of the maximum deflection of the system under different physical and dimensional parameters are compared and analyzed,which verifies the accuracy of the stiffness formula.The mapping relationship between each parameter and stiffness is fitted to optimize the system structure.Finally,the natural vibration characteristics of the system are studied,and the influence of vibration on electronic components is analyzed.The first 15 order natural frequencies of the system are studied as a function of physical and dimensional parameters.The increasing coefficients of the first 3 orders of free vibration of the system are calculated.The influence of each parameter on the overall stability of the system is analyzed.The conclusion of this paper is convenient for more accurate study of mechanical properties and vibration characteristics of spatial composite structures.The optimization suggestions of the system are given in terms of physical parameters and dimension parameters,which can provide theoretical basis and technical scheme for the design and research of spatial composite structure.