Nová metodika návrhu velkokapacitních environmentálních nádrží zvyšující jejich vybrané užitné vlastnosti

Abstract

The dissertation thesis deals with the design of a methodology for increasing selected utility properties of large-capacity tanks. The methodology is focused on bolted tanks, as the design procedures for bolted and welded tanks differ in various specifications and thus a universal procedure cannot be applied. The tank wall consists of thin metal plates which are bolted together. The height of the tank is determined by the number of rows, while the diameter corresponds to the number of plates around the circumference. An important structural elements are the wind girders (wind stiffeners), which are used to increase the resistance to buckling. The designed methodology combines analytical and numerical approaches. The analytical part uses simplified equations that are given in the European standards. On the other hand, the numerical approach allows a more detailed assessment of the structure, using more accurate mathematical equations and physical models that better correspond to the real behaviour of the structure. To make the design more efficient, an automatic tool has been developed that can be used to design the composition based on the specified dimensions, loads and climatic conditions. Based on the defined input parameters, the tool very quickly designs the tank wall composition and the location of the wind stiffeners, including the size of the sections. The proposed composition is then assessed in more detail using a parametric numerical model. The numerical model is validated by experimental modal analysis, which is performed on a prototype of the tank. The designed prototype included real metal plates, bolted joints and sealants. Two configurations are tested - without girders and with L-shaped girder.

The designed methodology is applied to a study of six selected tanks of different sizes. The results obtained showed that the use of simplified analytical equations can have a significant impact on the accuracy and efficiency of the design. For this reason, it is recommended to use the proposed methodology combining analytical and numerical models in the design of the structure, which can be used to assess the specific structure in more detail.