500m口径射电望远镜(Five-hundred-meteraperturesphericalradiotelescope,FAsT)采用柔性索网+刚性面板的设计方案,变位观测过程中索网呈柔性,而面板单元则呈刚性,这就需要在面板和索网节点之间设计自适应连接机构,以避免面板在单元变位过程中受附加应力的影响。因应FAST的技术需求,主要完成了以下工作:进行自适应连接机构的自由度设计及机械设计,建立包含连接机构的FAST反射面整体有限元模型,并通过与理论分析结果的对比,验证了有限元模型的准确性;应用建立的有限元模型,计算索网在变位过程中自适应连接机构的运动范围,为FAST工程提供了必要的设计参数。
The reflector system of the five-hundred-meter aperture spherical radio telescope (FAST) is designed as rigid panels supported by a flexible cable-net structure. Shape-changing operation in process of observation will lead to relative displacements between the adjacent nodes of the cable-net. Meanwhile, three nodes on a rigid panel are fixed relatively. Thus, adaptive connecting mechanisms between panels and the cable-net are certainly needed to avoid the influence of additional stress during shape-changing operation. The present work focuses on the following aspects according to the technical requirements of FAST. The degrees of freedom and the structure of the adaptive connecting mechanisms are designed, and the finite element model of the reflector system with the adaptive connecting mechanisms is established. Then the theoretical algorithm is applied to verify the results calculated by the finite element analysis. The finite element analysis is carried out to calculate the scope of motion of adaptive connecting mechanisms during the shape-changing of the cable-net, thus providing input parameters for the design of adaptive connecting mechanisms.