Parametric study of the factors affecting the structural performance of braced domes subjected to gravity loads

Abstract

Nowadays, single-layer braced domes are widely used by architects and engineers. The strength, economy, and fast installation were the main reasons for spreading this system around the world. The architectural design constraints of a dome impose structural challenges for the design engineer, especially when the span is large, with a small aspect-ratio or heavy design loads. Therefore, the structural engineer looks for different methods to strengthen the single-layer braced dome. This paper studied three different methods for improving the structural performance of the single-layer braced dome, including the grid-density, the member geometry (size), and the bracing systems with double-layer. A total of 96 finite element models were analyzed and designed using SAP2000 commercial software. Four main types of braced domes were studied, including Schwedler, Ribbed, Geodesic, and Kiewit-6. Two different types of joint connections were modeled (i.e., rigidly-connected and pin-connected). In addition, all models were pin-supported at the bottom ring and subjected to static gravity load only.The results indicated that the joint rigidity had a significant impact on the linear buckling load and a minor effect on the maximum displacement and internal forces. Furthermore, it was found that the increase in grid-density, enlarging member size, or using bracing systems significantly improved the structural performance, but at the expense of increasing the of a single-layer brace dome 's weight.