Folding of sealed origami-inspired capsule with rigid panels and hyperelastic hinges

Origami structures have great potential for space applications owing to the advantages of high packaging ratio, diversified design and predetermined deployment. Inspired from a rigid origami pattern, a novel architecture for large-scale expandable capsules that incorporates a hybrid origami combining rigid panels and flexible hinges is proposed in this paper. The rigid panels ensure the structure with good loading capacity and reliable performance. The flexible hinges with hyperelastic behavior address the geometric mismatch and incompatibility when folding a 3D sealed structure. This paper focuses on the mechanical behavior of the expandable space capsule inspired from origami. Based on our previous work about kinematic analysis, two deformation modes of hyperelastic hinges are determined. Theoretical models to characterize the hyperelastic hinges are described using the hyperelastic constitutive model. Specific experimental devices are designed for the hinges with different deformation modes individually. The accuracies of theorical models are compared to finite element simulations and experiments, and the applicable ranges are evaluated respectively. Furthermore, the mechanical properties of a representative capsule unit are studied with the energy method. Using the theoretical model, a self-energizing deployment of the structure is discovered and then validated through simulation analysis and quasi-static folding tests. The results demonstrate that this proposed concept provides a novel approach to designing origami-inspired deployable structures for on-orbit construction in future space missions.