Figure 22: Dimpling Effect

Figure 22:  Dimpling Effect

With rubber leg struts and pressure on one of its vertexes, the tetrahedron would have to turn itself completely inside out (A) and thus retain its same volume negatively. Since its vertexial angles are more acute than are those of any other polyvertexia, the tetrahedron clearly has the greatest resistance of any structure to externally applied concentrated load. The octahedron folds into itself, leaving no interior volume (B), and the icosahedron (C), although dimpling locally and reducing its volume considerably when doing so, implies that it still has good resistance to concentrated load. The geodesic icosa-spheres (D and E) exhibit "very local" dimpling as the frequency increases, suggesting much less resistance to concentrated loads but very high resistance to distributed loads.

Back to Letter
Copyright 1999, Estate of Buckminster Fuller, all rights reserved.