Volume 2 Issue 3
Authors: Ali Ehsani Farimani; Mohammad Reza Maghareh; Hosein Abhar
Abstract: During the ages, architects and engineers have tried to cover the wide spans without using the columns. To access this objective, they have used the different kinds of domes. The materials used in these structural systems include the weighty materials like stone and brick. Since The Industrial Revolution, the rapid progress in technology and finding new materials has caused to devise more kinds of structural systems, which were used for constructing the domes with wider spans. The goal of this article is to provide a proposal for the classification of structural systems of large domes, based on the Case Studies, and to specify the abilities of these systems. In order to this purpose, 50 Large Domes, which have been constructed between the years 1964-2009, are selected as Case Studies, in beginning. The criteria for selection are: First, Structures must have a clear span of 100m or greater. Second, the size of a clear span is taken to refer to the diameter of the largest horizontal circle that will completely fit inside the structure. Third, Structures must be fully covered, or capable of being fully covered. A few Small holes in the roof are permitted. Fourth, Structures must be multi curvature. Thereafter, the data of the domes inserted in a table and 17 structural systems have been specified. In this paper the methodology of the classification for this kind of structures has been presented and the results have been discussed and concluded in the end of the article.
Keywords: Large dome; Structural systems; Clear span
Authors: Mokhtar Bouazza; Fodil Hammadi; Sara Seddiki; El Abbas. Adda-Bedia
Abstract: In this article, an analytical approach for mechanical stability analysis of moderately thick functionally graded rectangular plates is presented. The equilibrium and stability equations are derived according to the first order shear deformation theory. Using Navier's-type solution these equations are solved for the functionally graded rectangular plate with simply supported under different types of mechanical loading. The excellent accuracy of the present analytical solution is confirmed by making some comparisons of the present results with those available in the literature. Furthermore, the effects of power of functionally graded material, plate thickness, aspect ratio, loading types on the critical buckling load of the functionally graded rectangular plate are studied and discussed in details.
Keywords: Buckling; first order shear deformation theory; functionally graded materials; mechanical loads
Authors: Xiaomei Wan; Folker H. Wittmann; Tiejun Zhao; Fuxiang Jiang
Abstract: A non-destructive method of evaluation of volumetric strain due to microcracking was used to characterise microcracking in concrete prisms under uniaxial compression. Chloride profiles were also measured after the same concretes were exposed to chloride environment. The relationship among microcracking, stress level and chloride penetration of concrete was analysed based on the experimental results. Under compressive load the apparent chloride diffusion coefficient decreases until about one third of the ultimate load. Further increase of compressive load increases the chloride diffusion coefficient again. There is a close link between microcracking and stress level. The index of volumetric strain due to microcracking can be used to indicate the microcracking and study chloride transport into concrete under the influence of microcracking.
Keywords: Concrete; Uniaxial Compression; Microcrack; Chloride; Volumetric Strain