星载柔性可卷天线固有频率提升方法研究  

Study on Methods to Increase Natural Frequency of a Spaceborne Flexible Coilable Antenna

作　　者：陈夜 周徐斌[1] 杜三虎[1] 

机构地区：[1]上海卫星工程研究所,上海201109

出　　处：《航天器工程》2017年第5期40-45,共6页Spacecraft Engineering

基　　金：国家重大科技专项工程

摘　　要：柔性可卷天线是以卷曲方式收拢的新型可展天线,由于空间环境的复杂性,天线的动力学特性将直接影响其形状保持与形面精度,进而影响卫星的通信。针对天线展开后刚度不足的问题,采用有限元方法分析了天线的前两阶模态,对应的振型是阵面与伸展臂的耦合振动。为提升前两阶模态频率,从天线各组成部分的几何尺寸、材料等方面改变天线结构,发现天线整体的固有频率与伸展臂的刚度近似成线性关系,随柔性阵面的质量增大而降低。为此,结构加强的重点应放在伸展臂上,并优先选择轻质的阵面。此外,为避免悬臂式结构布局,提出了两种拉索设计方案,比较了拉索预紧力、拉索刚度对固有频率的影响,采用刚度足够大的拉索可使天线的固有频率提升至2Hz以上。Flexible coilable antenna is a new kind of deployable antenna which is stored by coiling.Due to the complex space environment,dynamic characteristic of the antenna has direct influence on the shape and accuracy of the surface,thus affecting the communication of a satellite.For the problem of the antenna's insufficient stiffness,the antenna's first two orders modes,corresponding to the coupling vibration of the surface and masts,are ana-lyzed based on the finite element method.In order to increase the first two orders' frequency,changes of components' geometric dimensions and materials are discussed.It is con-cluded that the natural frequency has a linear relation with the masts' stiffness,and it decreases with the increase of surface mass.Therefore,emphasis should be centered on the strengthening of masts and low-mass surface is preferred.In addition,two kinds of cable designs are provided to avoid cantilever layout,based on which,the influences of cable pretension and cable stiffness are discussed.With enough cable stiffness,the natural frequency could exceed2 Hz.

关 键 词：可卷天线 有限元 模态 固有频率 

分 类 号：V443.4[航空宇航科学与技术—飞行器设计]