Structural Mechanics

Today there exists standards which describes how wind-loads, statical and dynamical, can be treated for different kinds of buildings. In some cases these standards are to coarse which might result in results that aren’t pre-cise enough. This might be the case when structures interact with the wind and creates resonance phenomenons between the structure and the wind. Accurate calculations of the airflow around structures and the fluid struc-ture interaction can be performed with numerical methods such as the finite element method. One program that can be used to perform such calculations is LS-Dyna. In this master thesis a description of how such a model can be created is described. The results from the calculations are then compared to known phenomenons such as vortex shedding. The results from the sim-ulations show that vortex shedding appears at frequencies that gets closer to theoretical values as the element size gets smaller. The simulations also show that the structures in the simulations move, although these movements have not been evaluated. In this master thesis a larger three dimensional model was created as well. In this model the airflow around an enclosure for a telescope i studied. The calculations in these simulations were costly and any accurate results were not found. The simulation where performed as a test of a simulation of a large three-dimensional structure with a relatively complex geometry. i Detta är en tom sida