Abstract:

As the supporting structure of the active reflector of the Five-hundred-meter Aperture Spherical radio Telescope, the cable-net is connected with reflector elements through special mechanisms, to change its shape and form in paraboloid or sphere by active control actuators. In this process, reflector elements should adapt to shapes of the cable-net and avoid collisions. In order to provide complement protection for the operation of shape-changing, we obtain the basic principle and criterion of collision analysis of reflector elements. The structural relationship between cable-net and reflector elements enables the collision analysis to be transformed into the stress analysis of the corresponding cables. Through the stress calculation of the corresponding cables under a certain condition, the collision problem of reflector elements is analyzed. A basic criterion is given to show whether collision happens or not during normal shape-changing of the cable-net. Based on the analysis, a method is presented to analyze collisions of reflector elements by calculating the stress change of cables, and the analytical example and result are given. In some sense, the rationality of shape-changing of the cable-net and reflector under normal conditions is explained.

Key words: five-hundred-meter aperture spherical radio telescope, radio telescopes, antenna reflectors, reflector elements, collision analysis