FEM dynamic simulation technique for membrane structure deployment and model evaluation

This study developed a finite element method (FEM) dynamic simulation to visualize the deployment behavior of thin membrane structures in the space environment. The proliferation of space debris resulting from accelerated space development threatens the future of space. Numerous researchers have explored strategies to prevent artificial structures from remaining in space and becoming space debris. One such method involves utilizing a drag sail device to de-orbit artificial structures, which reduces their kinetic energy by inducing additional atmospheric drag, allowing them to re-enter the Earth's atmosphere. Tohoku University and Nakashimada Engineering Works, Ltd. have successfully developed a deployable membrane structure for de-orbit purposes and demonstrated its effectiveness in space. Space structures, such as membranes, exhibit highly nonlinear behavior due to their flexible properties, and ground tests by actual devices cannot fully demonstrate their deployment stability in a microgravity environment. Therefore, evaluating the deployment behavior using simulation methods instead of relying solely on hardware development is crucial. In this study, we employed FEM to establish a simulation environment, which enables us to consider nonlinear oscillations of flexible structures, such as the membrane. The simulation results closely reproduce the deployment motion observed in ground tests by appropriately incorporating constraint conditions related to deployment forces and hardware interactions, such as a hub component initially wrapped by the membrane. The simulation facilitated an assessment of the impact of membrane properties on deployment without the need for physically developing an actual hardware device. We proposed evaluation methods for determining membrane properties in terms of the trend of propagation of deployed surface area and the tendency of deployment motion. This established simulation technique can be utilized to develop future flexible space structures.