Behavior of Gabled Hyperbolic Paraboloid Shells

Abstract

Previous studies on gabled hyperbolic paraboloid shells (gabled hypar) revealed that shell loads are transferred to the supports mainly through diagonal arch action, and the contribution of edge beams, which have been traditionally included based on the assumptions of membrane theory, is actually very limited. This finding introduced a new shape of gabled hypars in which the edge beams are removed. This paper investigated the behaviors of gabled hypars with and without edge beams for various cases considering the effects of rise-to-span ratio (RSR) and lateral support movement. The FE analyses results indicated that, when the RSR was low, distribution of shell stress showed large variations. Lateral support movement caused an increase of tensile stresses, a decrease of compressive stresses, and intensified stress variation. When edge beams were not used, deflections were increased substantially, and local fluctuation of stress in the vicinity of the supports was intensified. Such behaviors were aggravated when RSR was low and proper constraints against the lateral support movement were not provided, thus resulting in inefficient systems. As such, gabled hypars without edge beams should be designed with caution.