Experimental Study on Folding Patterns and Deployability of Inflatable Structures

Abstract

In this study, the authors experimentally investigate the relationship between folding patterns and performances of inflatable structures; compactness and deployability. Inflatable structures are widely applied in various engineering fields such as airbags in automobile industry, inflatable building in architectural field, and inflatable satellite antenna and landing equipment to Mars in space engineering field. However, these two requirements can be a tradeoff, as a compact product is hard to deploy in general. As a possible solution, circular spiral patterns are adopted in this study, because 1) they can be simultaneously deployed along spiral fold lines that is an advantage on deployability, and 2) the removal of the core of the circular sheet can make the sheet folded more compactly that is an advantage on compactness. Inflation models with different design parameters are created and tested. As experimental results, the inflation time (i. e. deployablity) and the initial width (i. e. compactness) can be optimized simultaneously in terms of four design parameters, but a trade-off relationship is observed in terms of the rest parameter; the folding angle formed by the V-shaped fold lines.