Static and dynamic analysis of partially wrinkled membranes for tethered spinning solar sail applications

In this paper, structural analysis of a tethered spinning solar sail with ultra-thin film and tensioned cables is performed. The aim of this paper is to study the effect of the tether tension and the rotation speed of solar sail spacecraft, on the sail structural deformations and vibration frequencies. The commercial finite element software ABAQUS are used. The analysis is performed on a full-scale solar sail. Shell S4 and S3 elements are used to model the thin-film. The cables are models by T3D2 truss elements. A multistep analysis method is present. An initial imperfection is formed and added to the original finite element mesh to produce a perturbed mesh configuration. First, pre-stress in cable is applied to pre-tension the whole solar sail membrane. Then, nonlinear static analysis is performed to determine structural behaviour at the incoming solar radiation. Vibration modes and frequencies are analyzed from the pre-stressed structure. The displacement, stress results and the first four vibration modes are obtained. It is found that the vibration modes are closely spaced. The structural deformation is strongly affected by the stress level of the sail membrane. An optimum spin rate is needed to keep pretension of sail films and reduce structural local stress concentration. Overall, this work gives some results for preliminary structural design of a tethered spinning solar sail.