Load Carrying Test And Optimization Research Of Carbon Fiber-Aluminum Honeycomb Structure

Honeycomb sandwich structure has been widely applied in various areas, including aerospace field. And the amount of usage of composite material has become an important symbol to measure the advancement of a spacecraft. Considering the status of the large cost of sending a spacecraft, scientists now pay more attention to the research on load carrying capacity characteristics of sandwich structure and overall quality light weighting under the premise of meeting the load requirement. This research project has both great practical and economic significance.In this paper, a kind of box structural spacecraft model has been chosen as the object of research, and the following works have been completed.(1) According to the "sandwich" panel equivalent theory, using finite element method to model and simulate, we have made an equivalent of carbon fiber laminated and aluminum honeycomb sandwich structures to a layer of quasi-isotropic homogeneous material. Then we have calculated the equivalent mechanical parameters of honeycomb sandwich and carbon fiber truss structures through simulation method. And we have considered the effects of thin wall thickness, cellular arm length and other geometric parameters on the mechanical properties.(2) Analytical and experimental methods have been used to compare and verify the equivalent mechanical parameters obtained from FEM results. For the aspect of errors existing among analytical, experimental and FEM methods in outer surface of elastic modulus of sandwich, a sandwich model containing buckling of thin-walled structure has been created. And we have analyzed eigenvalues and nonlinear buckling of structure to improve the mechanical parameters of the equivalent sandwich structure.(3) A overall program of spacecraft structural optimization and design has been proposed. The whole structure modeling and simulation of multiple loading conditions have been completed by FEM. Static, modal, harmonic and transient responses of each component have been calculated comprehensively, including displacement and stress analysis of carbon fiber panels, carbon fiber truss rods, aluminum honeycomb sandwich and joints. Through the results of simulation analysis, we have found the weak areas of structure load carrying and the corresponding load conditions.(4) A local refinement sub-model of the structure has been created. And through interpolation of weak boundary region, we have obtained the calculation loading conditions of representative unit. By simulation we have completed the optimal design of representative unit, including shakedown optimization of aluminum panel-aluminum honeycomb sandwich structure.