Study On Dynamic Optimization Of Large Deployed Antenna And Structural Systematic Optimization

The research work in the paper is composed of two parts: the dynamic optimization of the deployable large flexible net antenna for satellite and the systemic optimization design of structure. The research work about the dynamic optimization of the deployable large flexible net antenna will be introduced as follows:1. In the paper, the research developments of satellite antenna are surveyed, which include its history of development and characteristic. The deficiencies and existent problems of study to deployable antenna are discussed, especially in dynamic optimization of deployable antennas. The significance about the research is pointed out.2. A classification is made to deployed antenna according to the difference of antenna reflector and the deploying force. This paper introduces applications of some new material in deployed antennas and forecasts the developments about satellite antenna.3. Considering the flexible cable net deployable antenna, the author have derived the nonlinear static analysis and dynamic analysis formulation of the tensegrity space structure and presented the calculation method. The dynamic properties of the structure are investigated by calculating a real example.4. The effects of pre-stressed cable, structural mass and the size of cable on shape accuracy and dynamic properties of the flexible cable net deployable antenna have been studied. The paper presents an optimum design model searching for minimum weight design with the constraints such as reflector precision, eigenfrequency, strength and forbidden frequency domain. The design variables include both the cross-sectional area of truss and stress of cable.5. The characteristics of the dynamic optimum design model of the deployable antenna are discussed, which is the highly nonlinear problem in terms of constraints and cable structure itself and the more complex problem for two kinds of variables, cross-sectional area of truss and stress of cable. To solve the difficult problem, an improved GAS is proposed by the author and used to deal with the problem.6. Based on the characteristic that the deployable antenna takes on two states, deployed state in the orbit of space and folded state in the freight rocket, an dynamic optimum design model is presented for the first time. The model is of pretty difference from the model with ordinary one for that it is a highly nonlinear problem and it is of two different states; i.e. deployed and folded states. The model is applied to a practical satellite antenna with good and useful results, which shows the validity of themethodology.7. It can be noted that the finite member analysis on the antenna structure in folded state is pretty difficult for its complexity. To solve the problem, the author presents a new method based on equivalent rigidity to deal with the structure with folded state. A simple effective modulus is founded. The effects of several material parameters on dynamic properties of the structure have been discussed.8. Considering the new flexible cable net deployable antenna, the author discusses the optimum design of cable system. An optimum design model is presented searching for minimum weight design while the constraints such as reflector precision is concerned. The design parameters are the number both of upper cable, below cable and adjustable cable. Through a numerical example, the theory above is tested to be correct and effective.The secondly research work is the systemic optimization design of structure. The followed work haven been done:1. The systemic optimum method based on GAS has been presented, in which the design variable is composed of topology, configuration and cross-section parameters simultaneously.2. This paper presents a new automatic truss layout optimization method. The method can grow least-volume trusses starting from the simplest layout rather than from a complex ground structure. The method has the advantage that it allows a structure to grow and degenerate towards an optimum topological layout.3. The type optimization was discussed for the first...