Abstract
Deployable gridshells are grid-like structures that can be deployed from a flat or collapsed configuration, simplifying the assembly and installation process. Additionally, the building elements can be fabricated using versatile manufacturing tools such as 3-axis CNC cutters. Typically, deployable gridshells are first assembled in a flat configuration and then shaped by applying increasing forces that induce elastic deformation of the beams and rotations at the joints. One of the major challenges in deploying these structures is achieving the correct opening of each joint to reach a predetermined target shape, as these structures often have many degrees of freedom. Moreover, once the desired form is achieved, the structure must be secured in place, either by locking the joint rotations or by adding bracing elements such as cables or bent beams. In this work, we address these challenges by introducing bistable collapsible gridshells structures that, due to their geometry, can collapse into a flat curve and maintain their deployed shape without the need for additional locking mechanisms. The structure can initially be assembled at rest in the planar collapsed state. Thanks to bistable equilibrium, the structure will snap into its target shape during deployment, as this represents the configuration with the minimum elastic energy among all possible deployed shapes. In the paper, we explain the geometric principles behind bistable equilibrium and design a demonstrator pavilion to showcase the potential of these structures.
