Design and construction of space frame structures with curved-crease origami-inspired flat-foldable nodes

Free-form space frames enable striking architectural designs but often require complex 3D nodes, leading to high construction costs. This paper presents a cost-effective solution using the curved-crease origami-inspired approach to achieve flat-foldable nodes. The proposed node features a self-locking mechanism that is activated upon reaching its 3D target state and is further reinforced by member insertion, preventing unfolding. Despite strict planarity and straightness design constraints, the proposed node can achieve vertex valences of two, three, and four, enabling diverse planar and non-planar configurations, demonstrated through a series of numerical and physical examples. Additionally, an optimization tool is developed to verify and modify input meshes for constructability. Results show that the proposed node can effectively realize double-ruled surfaces that naturally satisfy design constraints and support double-layer systems for free-form realizations. Beyond space frames, the node’s applications extend to tree-like structures, with key challenges and future research directions discussed.