A new cross section hypothesis-based approach for quantifying deployment characteristics of deployable inflatable structures

Deployable structures have demonstrated significant potential in various applications, such as space solar power stations and deep space communication due to their intuitive design, high folding efficiency, and compact launch volume. As their use becomes more prevalent, understanding the deployment mechanisms of these structures is increasingly essential. This study focuses on a specific type of deployable structures, known as inflatable membrane beams. We introduce a novel cross section hypothesis, proposing a triangular shape instead of the conventional elliptical shape to represent the cross section of an inflatable membrane beam undergoing bending deformation. This new hypothesis is then integrated into the theoretical framework. Based on this enhanced theoretical formulation, we develop two beam models, i.e., one with full enclosure and one with partial enclosure. These models allow us to analyze the effects of various parameters, including the beam deployment angle, the length and radius of the membrane beam, and the internal pressure of the beam, on its deployment moment. Extensive experimental analysis is conducted to deepen our understanding of the intrinsic relationships between these parameters and the deployment moment. The experimental results indicate that the new theoretical analysis offers superior prediction accuracy compared to the original theoretical model. The findings of this research provide theoretical support for the efficient and orderly folding, shape formation, and maintenance of large-scale deployable structures in orbit, contributing significantly to the future space missions and technologies.