Deformation strategy optimization of FAST cable-net structure for fatigue problem

The reflector of Five-hundred-meter Aperture Spherical radio Telescope (FAST) is supported by cable-net structure, so that to enable its reflector surface to form a paraboloid from a sphere in real time through active control. However, such form-changing operation would lead to about 500 MPa stress range for the cable-net structure. Such stress range is nearly twice as much of that defined by the relative standard. So the cable-net structure is the most critical and expendable part of FAST reflector system. The service life of FAST would directly depend on the residual fatigue life of its cable-net structure. Then, the present paper would make an effort to find a more appropriate deformation strategy to decrease the stress amplitude of the cable during form-changing operation.