The Caravel heX-Mesh pavilion, illustration of a new strategy for gridshell rationalization

The fabrication of a freeform structural envelope is usually a highly complex task. The costliest aspect is often the connections between the constitutive parts. The Caravel heX-Mesh Pavilion is a prototype that demonstrates a new rationalization strategy. Its structure, composed of a hexagonal grid of beams and cladding panels, is based on a geometry that rationalizes connections at two levels. Firstly, nodes are free of geometrical torsion and are repetitive: only two types of nodes are used. Secondly, panels can easily be connected to the support beams as they are orthogonal to each other. The mechanical behavior is validated by finite-element analysis. We generate these meshes by numerical optimization from a smooth target surface, with an initialization derived from the asymptotic case and surface theory. The pavilion shows an alternative way of rationalizing a gridshell beyond the popular planar-quad meshes and circular/conical meshes. It also demonstrates a way to generate hexagonal gridshells which are not necessarily synclastic, this limitation being typically imposed to achieve planarity of cladding panels.