| Summary: In this study it is aimed to perform the stochastic dynamic analysis of fluid and fluid-structure systems by using the Lagrangian approach. For that reason, variable-number-nodes two-dimensional isoparametric fluid finite elements are programmed in FORTRAN language and incorporated into a general-purpose computer program for stochastic dynamic analysis of structure systems, STOCAL, and named as STOCALF. This Ph.D. thesis in which stochastic dynamic responses of fluid-structure systems are obtained consists of four main chapters. First chapter consists of literature investigation about the subject. Formulations of deterministic and stochastic dynamic analyses of fluid-structure interaction systems by Lagrangian approach are given. In the second chapter, developed computer program is introduced. For control of the frequencies, modal analysis of a rigid fluid tank which is modelled by finite element method is performed. Also, a fluid-structure interaction system is modelled as an example. Stochastic and deterministic dynamic analyses of fluid-structure interaction system are realized and comparisons are made. Informations about the finite element models of the interaction systems and earthquake motion which is chosen are given. In the third chapter, a sample dam is chosen; stochastic dynamic analysis of dam-reservoir and dam-reservoir-foundation interaction systems are performed. Mean of maximum values, frequency of occurence values of the responses and cumulative distribution functions are obtained. Also various parametric studies are performed. In the fourth chapter, conclusions derived from this study are evaluated in details. At the end of the study it is underlined that the stochasticity of the earthquake motion must be taken into account to determine the responses of the fluid-structure interaction systems. Keywords: Lagrangian Approach, Fluid-Structure Interaction, Concrete Gravity Dam, Dam-Reservoir-Foundation Interaction Systems, Stochastic Dynamic Analysis, Finite Element Method |
