Stiffness Experiment on Prototype Back-structure of FAST

Five hundred meter Aperture Spherical radio Telescope(FAST) will be the largest radio telescope in the world which has three innovative engineering concepts. One of them is the active main reflector. Back-structure is the connection between panel and cable mesh of the reflector,which is significant of the entire FAST project. Three prototype back-structures have been designed and manufactured. They are cable supporting single-layer structure,single-layer grids structure and triangular pyramid structure. Stiffness experiments of the three prototypes took place. Compared displacements of different back-structures,between experiments and analyses data,and compared through different temperatures.The stiffness features are obtained.This serial stiffness experiments confirm prior designs and optimization. And have great reference in the future design.