Optimal Parameters Design For Spacecraft With Appendage Structures And Dynamics Of Coupled Rigid_Flexible System

As the development of spacecraft technology, it’s more and more urgent for the demand of the spacecraft with large appendage structures, just as the solar panels, and large antennas on the satellite. It’s important aspect to study the methods to minimize the mass of appendage structure in the section of structure optimization design with the condition of satisfying the function requirement of appendage structures. On the other hand, It’s turned to become coupled flexible_rigid multi-body system with the large appendage structures. In the condition of attitude adjusting and orbit changing for the spacecraft, it’s key problem for system research, integrated design and control of structures to analyze the perturbation of attitude system and the dynamic response with the dynamic loads. In allusion to the two problems, this paper studies the spacecraft structures with appendages, which include the ring truss deployable antennas, the solar panels, and the assembly antennas. The dynamics optimization design of deployable structures and coupled flexible_rigid system are lucubrated. The main contents of the paper are showed as follows:The mechanical properties of the honeycomb sandwich and ring truss structures are studied in the paper. The researches results are used for the design application of the spacecraft components. The equivalent parameters of the hexagonal honeycomb core are analyzed, and it’s validated the accuracy of the model with simulation method. The bending effect of the honeycomb sandwich structure is analyzed in analytical method. By comparison, the analysis with the flexural rigidity effect of the face sheets is done. And the equivalent model of the honeycomb sandwich structure is constructed for valuating analysis. Then, the characteristics of ring truss deployable antennas are studied. The finite element models of the antennas are established for the modal analysis. The similarity theory to predict the first natural frequency of ring truss deployable antennas is studied and applied in the paper.The sensitivity analysis for ring truss deployable antennas structural parameters is studied. The solution process for the sensitivity analysis of structural parameters is analyzed with global calculus of differences, semis analysis, and numerical simulation. The derivative numbers of structure stiffness matrix to the design variables are induced. The Newmark method of the sensitivity analysis for displacement response in dynamics is analyzed. The sensitivity characteristic for structural parameters of ring truss deployable antennas is studied, which contains the height of truss, the inner/outer diameter of member bar, and the aperture of the antennas. The relationships between the prestress in nets and the first natural frequency of ring truss deployable antennas are studied.The application of the ring truss deployable antennas using optimization algorithms with surrogated models is studied. The design of experiment applied in the structural optimization is analyzed by different sampling strategies. The surrogate models, include the PRS, Kriging, and RBF method, are induced in the paper. And the accuracy of the three surrogate models is evaluated. The structural parameters optimization for the ring truss deployable antennas is solved with GA algorithm, considering the Kriging models as fitness function and restraint function. The solutions are compared with the results by finite element method. The different parameters in PSO algorithm, included the inertia weight ω, self-learning factor 1c, and global learning 2c, affect the optimal performance. The application with PSO is studied to solve the optimal problem of structural parameters. Then the Kriging models, which are established by the relationship between the sample points and response values, are used to find the optimum solution with QPSO algorithm. Several modified surrogate models are presented in the paper, which includes the incremental response algorithm, modified Kriging models, such as EGO and SKO and so on. Two hybrid methods, such as HAM and MSGO algorithm, are presented based on the PRS, RBF, and Kriging models in the paper. The application on structural parameter optimization of ring truss deployable antennas is studied. The optimal results show the merits and drawbacks of all the algorithms.The coupled dynamics between the flexible appendages structures and the spacecraft is studied. The spacecraft attitude dynamics model with flexible beam structure is established. The research results are promoted to the complicated flexible structures. The effect to spacecraft attitude dynamics by flexible appendage structures is discussed, which include the assembly antennas, solar panels, and ring truss deployable antennas. The coupled effect between the solar panels and spacecraft attitude dynamics is studied. The co-simulation analysis scheme, which is based on structure dynamics, attitude dynamics, and structure optimization design, is established with integrated design, and the simulation results are analyzed. The rigid_flexible system affected by the solar panels, which are rolling on the orbit, is studied. The coupled mechanics of the rigid_flexible system is analyzed profoundly.The coupled system of spacecraft attitude and orbit is designed systematically. The integrated design scheme and software configuration system of coupled between spacecraft attitude and orbit is established. The effect to the spacecraft orbit by nonconservative force perturbation is studied. Based on GEO spacecraft, the effect to the spacecraft attitude and orbit by solar pressure model is studied. The function of the coupled system between spacecraft attitude and orbit is designed to realize the process, which includes the structural dynamics module, structure optimization module, attitude dynamics, orbit determination, and integrated modeling environment. The interface of the module and parameter list of the coupled system between spacecraft attitude and orbit are designed at the end of the paper.The dissertation combines the research domain of the traditional optimization design and coupled rigid_flexible system. There’s some theoretical significance for it can solve the structure design in engineering in a certain extent. Meanwhile, the developed theory, models, and algorithms in the paper combined with engineering constraints, can promote the applications of optimization design in engineering. There is some reference value for the spacecraft structure engineering design and verification.