Experimental Investigation of Thin-Steel Hyperbolic Paraboloid Structures

Extensive tests on inverted umbrella and saddle-shaped models indicate that the design of thin-steel hypar roofs is usually governed by stiffness, rather than by stress limitations. The rise-span ratio and the shear rigidity of cold-formed decks are the most important factors determining the stiffness of the structure. Deck buckling is causd by the uniform shear stresses in the shear-diaphragm type of action of the shell which dominates the response of hypar shells. This experimental investigation yielded empirical design information in thin-steel hypars and also provided checks on other analytical studies.