Avaliação computacional do comportamento dinâmico estrutural de plataformas fixas submetidas a carregamento de ondas marítimas

Abstract

Oil platforms are influenced by loading conditions different from those encountered in usual structures onshore. Because of that, designers must consider a set of complemen-tary analysis for keeping the safety and efficiency of the operation. Within this context, steel jacket platforms are tubular structures, similar to towers, that remain fixed to the ocean beds and are widely used for exploration in shallow and intermediate waters. In these platforms, the collision of the sea waves in most of the cases is considered to be the main loading. Therefore, the characterization and measurement of the sea waves loa-ding is a fundamental stage for the modeling, analyses, and design of offshore structures. The main goal of this work is to present waves theories used in the modeling of the sea state, aiming to evaluate the loading on a jacket platform and its dynamic behavior. The structural analysis is done by using two-dimensional models obtained through the Finite Element Method. The results obtained were compared with consolidated data from mo-dels available in the literature and it shows convergence of the results of linear and Stokes theories in waves whose amplitude is small in relation to their length and local depth.