From multiscale modeling to design of synchronization mechanisms in mesh antennas

Flexible multibody simulation is supposed to be a promising method for studying the deployment dynamics of large mesh antennas and assisting the design of the related crucial mechanisms. However, fulfilling a full-scale deployment simulation of a mesh antenna is so challenging that it can be rarely found in the literature. In our opinion, the bottleneck of modeling some mesh antennas is dealing with the multiscale physics mainly sourced from the cable-pulley systems that are frequently used to transfer forces for long distance range. A traditional model of a cable-pulley is based on contact method, which involves fine cable mesh, a large amount of contact detection, and small time step for numerical integration, resulting in low calculation efficiency. To cope with this difficulty, we proposed a novel and efficient multiscale method to handle the cable-pulley systems. The basic idea is avoiding the contact detection by separating a cable into two segments: non-contact and contact segments, according to which part of the cable is in contact with the pulley. The non-contact segment is meshed with variable-length elements based on the arbitrary Lagrangian-Eulerian (ALE) formulation. The contact segment is considered an invisible segment to constrain the variable-length cable element on the pulley; its border is dynamically located by the relative configuration between the pulley and the cable. The accuracy and efficiency of the proposed method were confirmed by a numerical example. Then, it was used to evaluate, compare and design the synchronization mechanism in a kind of mesh antenna. The obtained results can directly guide the actual design of mesh antennas, and the proposed multiscale method can be applied to simulating other similar mechanical systems.