Frei Otto’s doctoral thesis on roofs hung in tension from masts and cables, which founded the modern study of lightweight, form-finding structures.
Otto argued that structures in pure tension use the least material, and that their form cannot be imposed but must be found: by soap films, hanging chains and stretched fabrics, which settle naturally into the shapes of least tension and surface. He founded the Institute for Lightweight Structures at Stuttgart in 1964 and designed, with others, the German pavilion at Expo 67 in Montreal and the cable-net roofs of the Olympic park in Munich (1972).
The book, part by part
I Tension structures
Membranes and cable nets, prestressed into anticlastic (saddle) shapes; form-finding with models.
Rules: A membrane must be a saddle