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 for roofing. The strength, economy and fast installation were the main reasons for spreading this system around the world. The architectural design constraints of dome put the challenge on the structural design engineer especially when the span is large, small aspect-ratio or heavy design loads. The structural engineer looks for different methods to strengthen the single braced dome. This paper focused on three approaches to improve the structural performance of the braced dome i.e. grid-density, member geometry (size), and bracing systems with double layer. Four main types of the braced dome were studied i.e.  Schwedler, Ribbed, Geodesic, and Kiewitt-6. A total of 96 structural models were investigated including models with rigidly-connected and pin-connected, pin-supported at bottom ring and subjected to gravity load. The models were designed and analyzed using SAP2000 commercial software. The results indicated that the joint-rigidity had a great impact on the linear buckling load, and a little effect on the maximum displacement and internal forces. The increase of grid-density, enlarge member size, or using bracing systems significantly improves the structural performance but compromised the weight of the dome.