多柔性附件卫星热致振动特性研究

Study on Thermally Induced Vibration Characteristics of Satellites with Multi-flexible Appendages

空间环境的温度突变是诱发卫星柔性结构振动的重要因素,对卫星的稳定度与有效载荷的性能带来不利影响。为研究进、出地影期间的温度突变在多柔性附件卫星上产生的振动效应,文章分析了热致动力学基本方程,提出了振动响应的解耦分析方法。以某遥感卫星为背景,建立了整星级有限元模型,以卫星进、出地影期间的动态温度场为载荷条件,运用ABAQUS软件隐式动力学模块开展动态响应分析,发现卫星在出地影后发生了明显的热致振动,其中高精度平面阵天线上的最大振幅约3μm,振幅在800 s内衰减了90%。为辨识振动的频率组成与源头,采用快速傅里叶变换将振动时域响应转换到频域,发现抛物面天线的弯曲振动在其他附件上产生了牵连振动,若要进一步提高平面阵天线的稳定性,应同时考虑柔性伸展臂与抛物面天线的振动抑制。

Temperature jump is a significant factor leading vibration of satellite flexible structures,which could arouse adverse effect on stability and payload performance of satellites.Aiming at the vibration of flexible satellites caused by temperature jump between sunshine and shadow,basic dynamic equations of thermally induced vibration are analyzed and the decoupling analysis of time domain response is presented.Based on a remote sensing satellite,a finite element model is established.Taking the dynamic temperature field as load condition,dynamic response is analyzed in the ABAQUS implicit dynamics module.It is found that thermally induced vibration occurs during the period of exiting shadow.Specially,the maximum amplitude of the planar array antenna is 3μm,and it declines by 90%over 800s.To identify the frequency composition and source of the vibration,the time domain response is transferred to frequency domain by FFT,finding that the bending vibration of parabolic antenna has aroused implicated vibrations on other appendages.To achieve higher stability of the planar array antenna,vibration suppression of the flexible boom and the parabolic antenna should be considered together.