Finit elementanalys av cisterntak

Abstract

Cisterns are often used for storing liquids, these can in many cases be dangerous and are therefore subjected to inspection. Calculation in connection with design control is in many cases required and is largely performed using formula-based methods. For some parts of the cistern, calculations with finite element analysis (FEA) can be meaningful. One concern for these FEA calculations is the time required for the modeling of the design as well as the execution of different load cases. By developing an FE model, which can easily be adjusted to the desired dimensions and materials and can perform a realistic evaluation of the strength, both time and money will be saved. The FE model's analysis has been limited to contain only the roof of the cistern and should be located in the Gothenburg area. The model is based on full contact surface between neighboring parties, this being because it has been defined that welds should not be included in the model, this is to simplify the model and then welds are not considered critical to the design. The work has been carried out at Chalmers premises in Lindholmen as well as DEKRA industrial office on Gamlestadsvägen in Gothenburg. Where study of the supplied drawings has laid the foundation for the development of a reliable FE model. Through work in Solidworks, the model was developed which can easily be changed to the desired dimensions and materials. Hand calculations have produced the load cases that will be assigned to the model, which is based on excerpts from Eurocode standards. By performing the hand-calculated verification calculations, the FE model's reliability could be analyzed. The FE model's finite element analysis was carried out in the Ansys program, where its results have been analyzed against accepted Eurocode standards. The results of the work show a simple adjustable FE model which, with the FEA, provides a good and credible evaluation of the model's strength. The results from the verification calculations indicate that the model is correctly loaded and shows a credible result. The evaluation of the result does not take tilting and cracking into account.