A Servey of Using Eqale Truss in Analysis of Composite Double- Layer Barrel Vaults

Analysis of composite structures, including space frame structures with concrete shell have been taking meny attention from researchers and different methods is being used for analyzing such structures. In this paper, based on the substructures metod and the theory of equivalent section, analyzing the actual structural model, a transverse strip alone has been analyzed to show that if the structural and loading symmetry can be a single strip from the entire structure or not. For the ease, using the theory of equivalent section, composite structure including steel truss structure and concrete shell can also be changed to a equivalent of truss. On this way, three models including main structure, a single element of structure and equivalent steel truss, modeling and analyzing havebeen done by using SAP. In order to review and compare the results, while using symmetry, the results in four parts of the structure have been evaluated.Then the results of analyzing the models. Have been summarized in the tables and then changed to the graphs.The results show that in analyzing and studying the behavior of composite double-layer barrel vaults, we can make use of the single strip composite truss or its equivalent steel truss in place of the whole structure in case studies.