The reflector of FAST (Five-hundred-meter Aperture Sphere Telescope) is a net mesh structure and can be considered as
a flexible parallel motion mechanism array which can form the varying paraboloid surface by controlling the motion of
the net mesh nodes. As a parallel mechanism, the motion of the nodes are coupled together. In order to release the
coupling, or to estimate the surface error of the reflector, the motion of FAST 30m Model was simulated combined with
ADAMS and SIMULINK. The net mesh mechanism was modeled as springs and spheres with mass in ADAMS software.
To control the large amount of actuators, and to analyze the motion of the net mesh motion mechanism, a control model
in SIMULINK has been built, which includes astronomical plan, actuator controlling and surface analysis. The model
can be used as the test tool of the actuator control strategy and optimization for the net mesh structure. With the
combined simulation, the amount of the couple phenomenon is estimated precisely. The paraboloid shape forming and
moving in the observing course is simulated, and the variation of the surface error of the reflector and the forces of each
cable are given. By the simulation, it can be concluded that the couple effect is small in the FAST 30m Model, and such a
method can be applied to the FAST prototype.