Abstract: The middle flexible belt is an important part of the loop deployable antenna. With the explosion of retracting actuator, the composite belt and the loop truss are expanded synchronously. Due to the strong flexibility of the composite belt, it will rebound around the fixed end of the root. Therefore, there is a risk of collision between the metal joint and the composite thinwalled pipe on the truss during the deployment process. As the antenna diameter increases, the risk will continue to increase. Based on the flexible multibody dynamics theory, the dynamic modeling and simulation of the belt deployment process of the super large loop antenna were carried out. On this basis, the minimum distance between the metal joint and the loop truss during deployment process was mainly related to belt damping rate and the truss preview speed. After further research, it was found that the bigger the damping rate of the composite belt, the longer the minimum distance between the metal joint and the loop truss during deployment, and that the faster the truss preview speed, the shorter the minimum distance between the metal joint and the loop truss during deployment. In addition, the law of change of the minimum distance between the metal joint and the loop truss in the process of deployment under the condition of failure of ratchet device in space was obtained. This research can provide a basis for the optimal design of the super loop antenna structure and the prediction of the belt deployment in space.

Key words: super large loop antenna, flexible belt, dynamic modeling and simulation, damping rate, preview speed, betoken in space