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Algorithms for design and analysis of membrane structures
Lang, Rostislav ; Krejsa,, Martin (oponent) ; Kytýr, Jiří (oponent) ; Němec, Ivan (vedoucí práce)
The present thesis deals with membrane structures, focusing on the description of both the inherent physical necessitates which has to be dealt and the algorithms used when developing the FEM software. After introducing physical basis of the individual design and analysis steps, the specific issues associated with these calculation procedures as well as the particular solution processes are described. The first chapter deals with the form finding analysis, which is inherently associated with designing tensile structures. The equilibrium shape is derived from the requirement for the resulting prestress, given boundary conditions and applied external load. However, this process is also generally dealing with a complex task of searching for the equilibrium itself. Therefore, necessary stabilization techniques are an inherent part of the calculation procedures. The selected methods as well as the proposed technique specialized for the calculation of conical membranes are presented. In addition to the given thesis scope, the proposal of an algorithm for dealing with optimizing the shapes of arches and shells is described. In the chapter about the structural analysis, the main focus is given to the phenomenon of membranes wrinkling. This sudden loss of stability, when the compression occurs, strongly affects the structural response. The proposed algorithm is presented, which is modularly applicable to both the elastic and inelastic materials as described in detail. The chapter dealing with the cutting pattern generation process presents the proposal of the selected combination of two existing solution methods. This algorithms sequence focuses on reaching the optimum combination of the calculation speed, generality and precision. The individual chapters are complemented by presenting of the examples analyzed by using the described algorithms, which demonstrate the individual physical or implementation issues and the associated solution procedures.
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Algorithms for design and analysis of membrane structures
Lang, Rostislav ; Krejsa,, Martin (oponent) ; Kytýr, Jiří (oponent) ; Němec, Ivan (vedoucí práce)
The present thesis deals with membrane structures, focusing on the description of both the inherent physical necessitates which has to be dealt and the algorithms used when developing the FEM software. After introducing physical basis of the individual design and analysis steps, the specific issues associated with these calculation procedures as well as the particular solution processes are described. The first chapter deals with the form finding analysis, which is inherently associated with designing tensile structures. The equilibrium shape is derived from the requirement for the resulting prestress, given boundary conditions and applied external load. However, this process is also generally dealing with a complex task of searching for the equilibrium itself. Therefore, necessary stabilization techniques are an inherent part of the calculation procedures. The selected methods as well as the proposed technique specialized for the calculation of conical membranes are presented. In addition to the given thesis scope, the proposal of an algorithm for dealing with optimizing the shapes of arches and shells is described. In the chapter about the structural analysis, the main focus is given to the phenomenon of membranes wrinkling. This sudden loss of stability, when the compression occurs, strongly affects the structural response. The proposed algorithm is presented, which is modularly applicable to both the elastic and inelastic materials as described in detail. The chapter dealing with the cutting pattern generation process presents the proposal of the selected combination of two existing solution methods. This algorithms sequence focuses on reaching the optimum combination of the calculation speed, generality and precision. The individual chapters are complemented by presenting of the examples analyzed by using the described algorithms, which demonstrate the individual physical or implementation issues and the associated solution procedures.
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