Title: Hyperbolic Paraboloid Shell Structures
Author(s): W. C. Scnobrich
Publication: Symposium Paper
Appears on pages(s): 1-16
Keywords: hyperbolic parabolic shells; reinforced concrete; roofs; shells (structural forms); structural analysis; Design
Shell structures mobilize geometry to activate both the membrane and the flexural internal force systems to efficiently support any distributed loads applied to those structures. Based primarily on their efficiency, these geometric structural forms are employed in a number of industrial applications such as pressure vessels, containment structures, etc., where the principal function of the structure is to contain or sustain a particular loading environment. This selection is especially true when substantial loads such as high internal pressures are involved. The shell structures selected for these applications are simple forms, most frequently combinations of various shells of revolution such as cylinders, cones, spheres, and (for the pressure vessels) the torospherical or ellipsoidal shapes, because of their ability to respond to most loads by a membrane state over the major area of the shell. Edge effects are confined to a narrow zone near the edge or around a zone of discontinuity that may be present as a result of geometry changes. In addition, shell forms contain a number of functional, economic and aesthetic virtues that make them logical choices for applications to building structures. For repetitive structures and for those needing long, column-free spans, reinforced concrete shell roofs have often been chosen. Furthermore, these structures provide a clean inner surface, often in a pleasant geometric shape. They have good fire-resistance qualities. By proper orientation or shape selection, glass areas can be placed so that natural lighting can be directed onto all or nearly all the covered ground plan.