大型平面薄膜天线找形及张拉成形数值分析

Numerical Analysis of Form-finding and Tension Forming of Large Planar Membrane Antenna

大型平面薄膜天线具有质量轻、收纳比高、环境适应性好等优点,在航天领域受到了愈加广泛的关注。针对一大型平面薄膜天线结构,考虑一级张拉与二级张拉两种张拉系统,利用ANSYS有限元软件对该薄膜天线进行了找形分析,并分别推导了两种张拉系统计算薄膜花边索形状的理论公式。利用找形分析的结果,在ABAQUS软件中建立了张拉成型分析模型,探究在张拉过程中,考虑拉索和花边索套之间摩擦力的情况下,膜面和拉索的应力状态。研究结果表明,在考虑摩擦力的情况下,膜面应力会有所增大,与此同时,膜面应力也变得不均匀,摩擦因数越大,应力不均匀程度越大。对于二级张拉系统,由于内外索连接点附近的膜面产生了应力集中现象,使膜面的有效面积率低于采用一级张拉系统时膜面的有效面积率。

Large planar membrane antenna has attracted more and more attention in the field of aerospace because of its light weight, high deployed-folded ratio and good environmental adaptability. Form-finding analysis of a large planar membrane antenna structure is carried out employing the finite element software ANSYS, and theoretical formulae for calculating curved silhouette of the prestressed membrane are derived respectively for two kinds of tensioning systems. By taking the results of form-finding analysis as the initial configuration, a tension forming analysis model is established in the finite element software ABAQUS, and tension process is simulated taking into account the sliding and frictional contact between edge cables and membrane sleeves. The results show that the stress on the membrane will increase when the friction force is taken into account. Furthermore, the stress on the membrane will become non-uniform. The larger the friction coefficient is, the less uniform stress of the membrane becomes. For the inner and outer cable combined tensioning system, the effective area ratio of the membrane surface is lower than that of the inner cable only tensioning system because of the stress concentration near the connection points of the inner and outer cables.