FoldEX: A Rapidly Deployable Rigid-Foldable Structure for Disaster Relief Sheltering

Abstract

Deployable structures provide significant advantages over conventional systems, making them ideal for numerous applications in architecture and engineering. Foldable structures, a notable category of deployable structures, are particularly well-suited for disaster relief shelters owing to their durability, adaptability, compactness, and high customizability. They generally feature simple mechanisms that ensure efficient storage and transport, withstand varying weather conditions, and eliminate the need for additional covering systems by utilizing rigid plates. Despite their potential, foldable structures have been the subject of limited research in the context of developing disaster relief shelters. This paper introduces a rigid foldable structure, FoldEX, designed to achieve compact folding for efficient transportation and rapid deployment as a disaster relief shelter. The proposed shelter folds from an expanded configuration of 4 m x 2.7 m x 2.7 m to a compact form of 4 m x 0.8 m x 2.7 m, achieving approximately a 70% reduction in storage volume. The system is designed for vertical stacking, allowing up to nine FoldEX units to be transported on a single truck. The shelter mechanism incorporates hinges strategically positioned along the panel edges to guide the intended folding directions, with each hinge allowing rotational motion - 1800 for small triangular panels and 900 for rectangular ones - to enable full folding and unfolding while maintaining structural stability. Following a kinematic analysis to characterize the motion patterns during the folding and unfolding, the design is validated through 1:10-scale 3D-printed prototypes, which demonstrate precise motion. Furthermore, three different unit combinations are proposed to demonstrate flexible layout possibilities.