|
Descripción
|
|
|---|---|
| In this thesis a statistical procedure for the resolution of dynamic problems at high frequencies is proposed and analyzed. In Chapter 1, the existing literature on the current methods for calculation of dynamic response of structures is studied, and the advantages and disadvantages of the principal procedures are indicated. The Method of the Statistical Energy Analysis is especially analyzed, because it has been chosen as base for this work for its simplicity, and its margin of improvement, both in the stationary variant and in the transitory one. In Chapter 2 three cases of stationary load are solved by the Method of the Statistical Energy Analysis: a system composed by two structural unidimensional elements (two connected bars); a system consisting of a structural unidimensional element (a beam) and a structural two-dimensional element (a circular plate); and a case of coupling between a structural element and an acoustic one, of three-dimensional character, represented by a rectangular plate in an acoustic cavity. From the study of these systems several results are deduced: first that the energy of every subsystem diminishes as the frequency increases. Secondly, that there is a way to interpret, analytically and graphically, the different regions relative to the transmission or the wave blockage across a specific structure. In addition to this, a way of identifying the existence of discontinuities in a structure, due to a change of material or of geometry, with the Method of the Statistical Energy Analysis, is proposed. Finally, for the fluid - structure interaction, a graphical comparison between the solution obtained by a statistical method, and the one obtained by a deterministic method, is presented for the first time, and it is possible to verify that in both cases the results adjust, in spite of being based on very different analysing procedures. In Chapter 3, the transitory problem, which in the existing literature is not much developed by statistical methods, is presented. On the one hand, an analytical procedure is proposed in order to extend the range of validity of the Method of the Transient Statistical Energy Analysis. Specifically, a theoretical procedure is proposed with the purpose of extending its applicability to generic cases of transitory load and to continuous systems. On the other hand, a practical application of this statistical transitory procedure has been applied to discreet and continuous systems. Also, several parametric studies, that allow the identification of the energy flow transmission paths for the considered systems, are presented. The results obtained for the analyzed examples have been confirmed either against the exact solution of the problem, or against the solution calculated by deterministic methods, and it has been shown that the proposed theory predicts, with good approximation, the behaviour of the systems. | |
|
Internacional
|
No |
|
ISBN
|
|
|
Tipo de Tesis
|
Doctoral |
|
Calificación
|
Sobresaliente cum laude |
|
Fecha
|
31/03/2010 |