Modelling of virtual compressed structures through physical simulation

This paper presents a simple specific software tool to aid architectural heuristic design of domes, coverings and other types of complex structures. The tool aims to support the architect during the initial phases of the project, when the structure form has yet to be defined, introducing a structural element very early into the morpho-genesis of the building shape (in contrast to traditional design practices, where the structural properties are taken into full consideration only much later in the design process). Specifically, the tool takes a 3D surface as input, representing a first approximation of the intended shape of a dome or a similar architectural structure, and starts by re-tessellating it to meet user's need, according to a recipe selected in a small number of possibilities, reflecting different common architectural gridshell styles (e.g. with different orientations, connectivity values, with or without diagonal elements, etc). Alternatively, the application can import the gridshell structure verbatim, directly as defined by the connectivity of an input 3D mesh. In any case, at this point the 3D model represents the structure with a set of beams connecting junctions. User defined custom constraints (reflecting physical ones) can be imposed over this resulting structure in an quick and intuitive way. Points on the surface can be constrained to never leave a specific position, line or plane. A physical simulation is then run, with the objective of obtaining a surface that, while preserving to a certain degree the initial shape, and fulfilling the constraints, represents a valid compressed structure, i.e. one composed by sub-elements which are only subject to compression, without residual bending forces. It is a well established fact, in architecture, that this property allows for elegant structures which can be realized with lighter and cheaper materials (as testified for example by the pioneering work of Spanish Architect Antoni Gaudì, or, more recently, of the Deutsch architect Frei Otto). During or after the simulation, constraints can be made weaker or lifted, and a few simulation parameters can be reedited, in an interactive way: resulting changes in the final 3D shape of the structure are made visible on the screen. The user can thus easily explore through a set of viable solutions all sharing with the aforesaid structural property. The final result is exported in standard 3D digital formats for further processing. In summary the proposed standalone application represents a quick and focussed tool to address a specific task.