Experimental Study on a Single Layer Two-Way Grid Shell with Tension Members

Single layer two-way grid shell with in-plane and out-of-plane tension members is a new type of single-layer latticed shell roofs. Compared with traditional single-layer latticed shells,this new type has a unique mesh form and excellent rigidity. In order to further understand the buckling behaviors of single layer two-way grid cylindrical shell roof with tension members,the buckling experiments have been undertaken to investigate the effect of tension members,in either out-of-plane or in-plane placement. A single layer two-way grid cylindrical shell roof with out-of-plane tension members has been tested under symmetric and asymmetric loading. The tension member placement,the introducing initial axial force to tension members and the load patterns are considered to investigate the buckling behavior. Experimental results indicate that four long out-ofplane tension members work well under symmetrical loading,but only two long out-of-plane tension members work under asymmetrical loading. It can be concluded that the PC bar members used as tension members for this study are useful in the construction of a single layer two-way grid cylindrical shell roof with structural members intersecting at small angles.

Structural optimization of four designed roof modules:Inspired by Voronax grid shell structures

Architects have been following nature in their constructions for a long time.Observations of nature reveal that it has many highly developed structures that provide scientists and engineers with a lot of useful clues for creating more efficient structures and building forms.Therefore,revealing systematic thinking about natural species is a crucial requirement for today’s buildings.A software analysis method was used to design four modules in the roof structure of the Iranian University of Science and Technology’s exhibition.The roof structure is based on the Voronax structure,which is a relaxed form of Voronoi,which is seen in the structures of many natural creatures.They were analyzed in terms of optimization and structural simulation using Grasshopper plugins and tools by taking into account Von Mises stress in the structural design.The results indicated that by increasing the density of Voronax cells in the areas with high Von Mises stress concentration,a more efficient structure could be achieved in terms of load-bearing and designing predefined free-form roof structures.By analyzing predefined roof structures in an optimum way,the study took a step toward optimizing these kinds of structures.