The purpose of this study is to analyse the structural behaviour of beams with variable cross sections or conical shape. The main focus therefore is put on the effects of hall frameworks in the second order theory. In the introduction, this paper emphasises the interests and conveniences of conical frames, especially connected to the example of hall structures. One of the most important aspects is the potential material saving by modification of the profiles affine to the stress resultants. Consequently highly stressed areas are widened while lower stressed parts of the member are kept thin. This economisation assures profitability which is one of the most important issues of todays technology. With regard to the structural analysis of conical frames initially there is the description of the theoretical background like the second order theory. This theory is required because of the high axial forces in hall columns. In applying the direct stiffness method, also known as the displacement method, transformation of the stiffness matrix and the force-vector are the intentions to describe a conical beam. At first a variable cross-section is defined by innovative parameters. According to Petersen, who displays a conical profile with the geometry of a two-point cross-section, the most important parameter is ? relating the two moments of inertia at the members start a and the members end b with the formula. (23) Once the conical shape is defined exactly the differential equation in the second order theory and its solutions are adopted in this paper. Additionally there is also the explanation of a conical beam in the first order theory with the aid of cubical shape functions. As a result the modified stiffness matrices and its forces can be established and are then implemented in the finite element method program Stiff. Now its possible to calculate frameworks with variable cross-sections expressed by its two moments of inertia. To verify the accuracy of these calculations a study of convergence between the conical beam and a graded beam, the comparison with results of the commercial program RStab and a stability examination are important parts of this thesis. The final calculation of a typical hall structure with different variable cross sections shows a possibility for the practical application.
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The purpose of this study is to analyse the structural behaviour of beams with variable cross sections or conical shape. The main focus therefore is put on the effects of hall frameworks in the second order theory. In the introduction, this paper emphasises the interests and conveniences of conical frames, especially connected to the example of hall structures. One of the most important aspects is the potential material saving by modification of the profiles affine to the stress resultants. Cons...
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