Development of folding method for three dimensionally foldable cylindrical structure with base

Abstract

Folding method of structures which are composed of hinges and panels are studied in origami engineering.There is an open issue in the origami engineering that folding method of cylindrical structure with base is unknown. In this study, author had elucidated the folding method of a cylindrical structure with a flat bottom from combination and modification of the folding method proposed in previous research. Two types of foldable cylinder with flat base has developed. One is a combination of the Sogame fold and modified Guest fold (structure A), and the other is a combination of the modified stent fold and Guest fold (structure B). Here, modification has been done in order to coincide their trajectories at their juncture. Then we evaluate the dissimilarity of trajectories at the juncture of base and side, transition of strain value during folding process, and the shrink ratio which is the ratio which is the ratio of deployed volume to folded volume. From evaluation of those element, we clarified that structure A can shrink about twice smaller than structure B in its volume, and the dissimilarity of trajectories and magnitude of strain are smaller for structure A than structure B. So it can be said that structure A has an advantage over practicality. Shape of the base is expandable to dome type by combing the Sogame dome or dome type Guest fold with Sogame fold. In addition, Sogame dome's top flat surface can be replaced by the modified Guest fold. Note that these proposed foldable structures are not rigidly foldable, but elastically foldable. These results will cause the expansion of the application range of origami engineering.