| To meet the requirements of economic development and reinforcing our national defence, studying large deployable space antennas become more and more imperative. It is a complicated systems engineering to study space antennas, witch comes down to many science fields and key techniques. The natural frequencies of the antenna are low and dense because of its large dimension, light mass and large flexibility. Dynamic analysis is needed to avoid the coupling motion between the satellite and the antenna.Firstly the thesis sets up the dynamics model of the satellite-antenna system based on the hybrid coordinates. The dynamic equation of the rigid-flexible coupling nonlinear system is derived based on Lagrange Equation by adopting centralized parameters method. And we make a numerical simulation of the antenna's supporting beam's vibration when the satellite is rotated a little angle surrounding the Z axis. We acquired the system's dynamic response when the satellite attitude was adjusted and the mode of the antenna. Then modal analysis and dynamic analysis have been done to the satellite-antenna system by using the finite element analysis (FEA) software of ANSYS. Through the analysis we got the system's connatural characteristic, the amplitude-frequency characteristic of harmonic response, the power spectrum density of random vibration response, the maximal amplitude and resuming time of impact response.Across the rigid-flexible coupling dynamic analysis, we acquired the coupled effects between the three-dimensional attitude motion of the satellite and the flexible vibration of the antenna's supporting beam, and got the dynamic behaviors of the system. And we found the change pattern of the antenna's structure parameters, which decide the system's connatural characteristic and its dynamic response. The results in this paper have the advantage of attitude control of the satellite and structural optimization design of the antenna. |
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