Deployable structures are rarely integrated into permanent architecture due to the inherent tension between structural self-weight requirements and the kinetic lightness necessary for deployment. Based on the analysis of the angled-rod linkages developed by Charles Hoberman, this paper explores a geometric solution and an approach to the construction of a hemispherical formwork that can be deployed in a variety of diameters to be used in the construction of curved masonry or concrete elements. Hoberman’s principle is adapted to the geometry of geodesic domes to develop a deployable hemisphere, modifying rods and nodes designs to ensure its optimal functionality based on the analysis of three prototypes of increasing scales, aiming to get closer to real-world architectural conditions. While balsa and acrylic models validated the geometric kinematics, the final laser-cut MDF prototype revealed critical structural limitations. As dimensions increased, the MDF prototype exhibited heightened torsional stresses at the connection points. These findings suggest that, while the Hoberman-geodesic hybrid is viable, as the scale approaches architectural reality, the complexity of its structural behavior increases.
Ferro et al. (Sun,) studied this question.