Hyperbolic- and Elliptic-Paraboloid Roofs

Abstract

In the previous chapters, we have discussed cylindrical shells, which are special cases of doubly curved shells. We now proceed to more general cases of such shells, the elliptic paraboloid shell and the hyperbolic paraboloid shell. Structural engineers refer to the first category as elpar and to the second one as hyppar. If built, elpars have a rectangular plan with curved edges (left shell in Fig. 8.1). Hyppars also have rectangular plans, but may have either curved edges (middle shell in Fig. 8.1) or straight edges (right shell in Fig. 8.1). Because hyppars on straight edges are applied most, we will pay most attention to this type, and start with them.