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عنوان پایان نامه Laboratory and numerical study of buckling behavior cylindrical shells of GFRP under external uniform pressure
چکیده :
· Buckling and Nonlinear Analysis by Finite Element Method:
The ABAQUS software [14] has been used to provide finite element modeling. The models are 300 and 150 mm in height and 1.6 mm thick in tanks. In the modeling of multilayer composite cylindrical shell in ABAQUS software, used for the mesh of four-sided and four-node elements (S4R), which is a two-curved element and has the ability to analyze large strains. The loading and boundary conditions of the model are determined in the loading environment. To apply external pressure, the inner surface of the cylinder is first selected. The loading method is also such that uniform pressure is introduced into the tanks environmentally. The supporting conditions of the specimen are arranged in detail. The bottom part is tangential in the three radial, tangential, and axial directions. At the top, the specimens have only radial and tangential Constraint, and the axial movement is free. (Fig. 1) shows how to load and apply... ادامه
عنوان پایان نامه Buckling behavior of GFRP cylindrical shells subjected to axial compression load
چکیده :
The subject of buckling and post-buckling has a relatively short history for composite laminatedshells in comparison with isotropic homogenous shells. Nevertheless, during this short timeconsiderable research has taken place and a remarkable attention has been became to the stabilityof anisotropic shell. Numerous studies on the modeling and analysis of composite laminatedcylindrical shells have been performed. However, the theories used in these analyses are mostlyextensions of the various isotropic shell models. Recently, for the purpose of optimum design ofcomposite laminated shell structures, fully anisotropic laminated cylindrical shells attracted moreattention by Weaver, Wong and Weaver, Semenyuk and Trach and Takano. In compositelaminated cylindrical shells, when the angles of fibers are not parallel in the cylindrical axis or notin the circumferential plane, the bending-twist and twist-extension couplings are presented.Hilburger et al. developed an analytical solution to... ادامه
نام نویسنده:
رباب ناصری قلقاچی
مقطع تحصیلی:
دانشجوی دکترای عمران- سازه
عنوان پایان نامه Experimental and Numerical Investigation of Capacity of Large Cylindrical Tanks with Stepwise Thickness under Combined Loading
چکیده :
Steel tanks designed in cylindrical form are a commonly used shell structure in industrialfacilities. In geometric terms, these tanks have a very small thickness compared with their otherdimensions and thus are categorized as thin-walled structures for which buckling failure shouldbe considered. The buckling failure of tanks containing liquids can result from different modes.One important collapse mode is buckling caused by the influence of combined loading on thetank wall. In this way for envestigation of behavior these tanks under combined loading, seviralexperiments done.
نام نویسنده:
ندا فضلعلی پور
مقطع تحصیلی:
دانشجوی دکترای عمران- سازه
عنوان پایان نامه Numerical and experimental analysis of finite length thin walled pipeline under combined compressive axial and external pressure load
چکیده :
pipelines are considered as thin-walled structures in which relative compressive axial and external pressure load may be created in some cases of fluid transmission. numerical simulations based on a 3D finite element model of the imperfect tube using the software ABAQUS are carried out. in addition for applying imperfections direct method is conducted because ideal pipeline would not buckle in FEA. In this study the influence of different axial loads on the buckling strength of pipeline under external pressure is investigated and interaction between axial load and external pressure has been demonstrated by a curve. Comparison of the results between numerical and experimental modeling also indicate good agreement between these two methods. based on extensive parametric studies, some significant conclusions were drawn.
نام نویسنده:
کیا بادامچی
ایمیل:
k.badamchi@urmia.ac.ir
مقطع تحصیلی:
دانشجوی دکترای عمران- سازه
عنوان پایان نامه Experimental and Numerical Investigation of the Buckling Behavior of Variable Thickness Steel Cylindrical Tanks under Wind Loading
چکیده :
Vertical cylindrical welded steel tanks are widely used for fluid and bulk storage in industrial and agricultural plants. They usually consist of a thin bottom plate, a cylindrical shell with uniform or stepped thickness and a closed-roof or open-top (with or without floating roof). With the development of economy and oil industry, more and more oil storage tanks are put into service in recent decades, especially large tanks.As typical thin-walled structures, tanks are very susceptible to buckling under wind load especially when they are empty or partially filled. Over the past few decades, buckling failures of cylindrical steel tanks and silos during windstorm have occurred in many countries and regions. Buckling of tanks sometimes even occurs under moderate wind load during their construction. Because of serious economic losses and environmental problems due to the destruction of storage tanks, studies about buckling of tanks under wind load have been conducted extensively over the... ادامه
نام نویسنده:
علی اکبر آذرخش
مقطع تحصیلی:
دانشجوی دکترای عمران- سازه
