由于地球的频繁遮挡,当地球卫星在低轨道运行时,卫星的可展开天线会处在高低温交替的环境中,从而形成剧烈变化的温度场.剧烈的温度梯度变化会导致柔性较大的可展开天线发生热致振动,降低卫星全极化探测头部等关键部件的寿命.首先建立某型号卫星的物理模型,然后利用有限元法对其进行在轨时的空间瞬态热分析,得到可展开天线的温度场,将温度作为约束映射到结构仿真中,再在结构有限元模型上分析卫星的热变形,实现卫星天线热致振动的预测并为天线结构优化设计提供数据支持.对卫星模型进行热分析可以监测各时期的温度场以及预测有可能发生的热致振动,从而在不断优化设计的基础上避免这种不利的扰动.%When the earth's satellite is in the low orbit, the deployable antenna of the satellite will be in high and low temperature environments alternatively due to the frequent shielding of the earth. Thus, severe temperature gradient changes can lead to thermal vibration of the deployable antenna with large flexibility. It will reduce the lifespan of some key components of the satellite such as the whole polarized detection head. In this paper, the physical model of the satellite is built. Then, the transient heat transfer analysis of the satellite in the orbit space is done by means of the finite element method and the temperature field of the deployable antenna is obtained. The temperature field is mapped into the structure simulation as a constraint and the thermal deformation of the satellite is analyzed using the structural finite element model. Finally, the thermal vibration of the satellite antenna is predicted and the data support is provided for the structural optimal design of the antenna. Thermal analysis of the satellite model can monitor the temperature field in different periods and predict the possibility of thermal induced vibration so as to avoid this kind of unfavorable disturbances through the successive optimization design.
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