Repetitive Structures

Abstract

This paper presents a theoretical framework of repetitive structures and illustrates its potential for the design and construction of strained gridshells. Throughout the history of architecture, the use of repetitive building parts has been a key goal to simplify fabrication, ease construction, and save costs and time. This may be achieved by laying identical bricks or using identical ball joints, dividing a sphere into congruent triangles or rationalizing a curved façade to only use planar glass panels. In any case, using repetitive parts inevitably effects the overall shape and layout of a structure. In geometry the term “repetitive” is used to describe congruent elements, such as nodes, edges or faces, within a network, while an architectural structure aims at identical building parts to achieve repetition. These two perceptions do not always coincide: In practice, adjustable joints, tolerances or deformation allow the use of repetitive parts, even for geometrically variable elements. The following paper combines insights from differential geometry and building construction to create a holistic theory of “repetitive structures” considering both the geometric and constructive parameters. This theory offers more than an analysis of existing structures. Through computational design we can systematically investigate the morphology of repetitive networks, define parametric relationships, identify fundamental principles of form and deduce parameter combinations for future designs.