Modal analysis of modular cylindrical deployable sunshield structure

The modular deployable sunshield is a rigid-flexible coupled multi-body system composed of a rigid support structure and a flexible film. To better understand the dynamic characteristics of the structure, a modal analysis of the modular cylindrical deployable sunshield structure is conducted. Firstly, the structural design and deployment principle of the deployable rigid support structure of the sunshield based on the Sarrus mechanism are explained. Secondly, a flexible deployable film design based on the Kresling origami model is carried out, and a prototype of the sunshield is developed and microgravity deployment tests are conducted. Thirdly, using the finite element simulation software ANSYS and the APDL parameterisation modelling method, finite element models of the cable-free rigid support structure, the cable-supported rigid support structure, and the overall sunshield structure are established. Finally, the correctness of the models is verified, and an analysis of the influence of tension cables and thin films on the natural frequency of the structure is carried out. The influence of geometric parameters and material properties on the natural frequency is studied, and a sensitivity analysis of the influencing factors is performed. The research results indicate: configuring tension cables increases the average natural frequency of the cable-free structure by approximately 130.98%; configuring the membrane reduces the average natural frequency of the cable-supported structure by approximately 37.27%; the maximum positive sensitivity is 0.4926 when the diameter of the third-order tension cable increased, and the minimum negative sensitivity is -0.3492 when the density of the fourth-order film increased. This research can provide a certain reference for basic research and engineering applications of similar deployable sunshields.