中文摘要：

500m口径射电望远镜（FAST）3E要以短程线索网作为反射面支承结构。该文通过对三种短程线分型的索网进行对比分析，建议五轴对称分型方法作为优先选择索网分型方案。同时，该文的优化设计工作进一步减少了主索网与圈梁连接节点的种类及数量，并使索网能满足馈源仓检修升级功能。在此基础上，针对现有两种反射面单元自重情况，优化了索网截面和内力水平，讨论了下拉索节点位置精度对索网变位精度的影响，量化了索网变位过程中主索节点的侧偏量。

英文摘要：

The geodesic meshed cable-net structure has been designed as the supporting structure of a Five-hundred-meter Aperture Spherical radio Telescope （FAST）. The compartive invetigation was proformed among three types of geodesic meshed cable-nets in the present work, then a five-symmetry axis-plan was thusly sugguested as a preferred mesh plan. Furthermore, the optimization work, according to the suggested mesh plan, has been performed to reduce the types and quantity of the connection joints between the cable-net and the ring beam. Finnally, the finite element model has been established to study the influnce of the selfweight of the relector element on the force distribution of the cable-net, to discuss the sensitivty charactor of the position of a down tied cable to the precision of cable net deformations, and to caculate the tangential displacement of a cross node of cable in its deformation procedure.