中文摘要：

500 m口径球面射电望远镜（ FAST）采用柔性索网作为主要支承结构，通过促动器连接下拉索控制索网变位实现观测。 FAST已步入工程实施阶段，相对于理想计算模型，实际施工中存在许多偏差，因此基于结构安全考虑有必要进行索网结构参数敏感性分析。通过科学合理地设定不同结构参数偏差分布，结合单参数和多参数敏感性分析方法，建立有限元模型对结构受力特性进行分析，结果显示拉索下料长度偏差和索体弹性模量是影响拉索索力的主要因素。同时多参数偏差敏感性分析的结果表明，拉索索力变化范围在－19％～27％。

英文摘要：

The Five-hundred-meter Aperture Spherical radio Telescope （ FAST） is supported by a net of cables, which enables the FAST antenna surface to be a real-time paraboloid through active control.The FAST project is now entering the stage of construction and implementation.However, considerable errors exist in practice and can result in deformation of the net from its ideal shape.In order to maintain structural safety of the FAST it is necessary to perform certain sensitivity analysis of the net for value deviations of structural parameters.In this paper we reasonably consider the variation ranges of structural parameters.We then perform certain analysis of the sensitivities of the net structure to value deviations of single parameters and to simultaneous value deviations of multiple parameters.Specifically, we use a finite-element model to investigate influences of value variations of structural parameters on the static forces in the net.We conclude that value variations of several key parameters such as the cable blanking length and cable elastic modulus have large impact on the forces in cables.Our results for simultaneous value variations of multiple parameters indicate that the variation range of forces in cables of the net is -19%to 27%.