Parametric study of the catenary dome under gravity load

Abstract

The catenary form is optimal for arches and singly curved (non-gaussian) shells, i.e. the catenary arch is a momentless and tensionless structure under self-weight. This advantage is especially appealing for the construction of low-rise structures built from materials which perform poorly in tension, e.g. masonry and concrete. Though the catenary is particularly important in arch and vault design, it also engenders a form for domes which, although not momentless, is in pure compression under gravity load. In this paper, the structural efficiency of the catenary dome is presented by finite element analysis (FEA) and membrane stress solutions. These analyses confirm that catenary domes experience only compressive hoop and meridian stresses under gravitational (self-weight) load. The influence of materials and geometric characteristics (e.g. thickness and height) as well as support type for several concrete domes are also investigated. These analyses revealed that Poisson’s ratio and shell thickness had the largest impact on the hoop stress and bending moment, respectively, toward the dome base. Nevertheless, all catenary shells considered remained in pure compression, irrespective of the parameter changes. Finally, the catenary dome is compared with circular, elliptical, and parabolic profiles to highlight its structural efficacy over these more conventional forms.