Fault analysis of the feed support system for the FAST telescope

China is now building the largest single dish radio telescope in the world in Guizhou province, which is called Five-hundred meter Aperture Spherical radio Telescope (FAST). The main purpose of this paper is to qualitatively analyze mechanical reliability of the feed support system for FAST. The design of the feed support system with a large complex hybrid mechanism is described. According to different functions, the feed support system is divided into three subsystems. Then, Fault Tree Analysis (FTA) is adopted to produce the failure logic diagram of each subsystem. Fault status of each subsystem is set as the top event, and all the underlying factors that cause the top event are finally found out. The study in this paper provides a theoretical basis for the coming reliability analysis of the feed support system for FAST in the next step.