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COB802 PREDIÇÃO DE MOVIMENTO DE VEÍCULOS OCEÂNICOS/THE TIME PREDICTION OF OCEAN VEHICLES MOTION

Helio Mitio Morishita

Departamento de Engenharia Naval e Oceânica, Escola Politécnica, USP

Av. Prof. Mello Moraes, 2231 CEP 05508-900, São Paulo, Brasil - E-mail: hmmorish@usp.br

The study of the time prediction of ocean vehicle motions has always attracted the attention of naval architects due to its potential application to improve the performance of control systems of certain marine operations. The motion of an ocean vehicle is due to random action of wave and wind and it is influenced by its speed and load. Therefore, the vessel dynamics can be adequately modelled as a time variant stochastic system and an attempt to predict its motions can be based on adaptive approach developed to stochastic systems. In this paper the prediction of a ship roll motion based on an ARMA model is analysed. The coefficients of the model are estimated using the recursive prediction error method. The study is carried out using data collected during sea trial of a ship and a potential application is shown in the landing of a helicopter on the vessel.

Keyword: estimação recursiva, predição adaptativo, movimento de navios, recursive estimation, adaptive prediction, ship motion

COB1191 FLUXO DE ENERGIA VIBRATÓRIA ENTRE CHAPAS REFORÇADAS POR VIGAS / POWER FLOW BETWEEN BEAM-REINFORCED PLATES

Acir Edvam Ozelame¹, Arcanjo Lenzi¹ e Ayres Elias Sada²

1 - Laboratório de Vibrações e Acústica (LVA) Depto de Engenharia Mecânica, UFSC, cp. 476 - CEP 88040-900 -tel. 048 234 0689 - fax 048-234 1519 - Florianópolis - SC, email: arcanjo@emc.ufsc.br

2 - CENPES - PETROBRÁS - Ilha do Fundão, Rio de Janeiro, RJ

This work deals with modal density and coupling loss factors analysis of beam reinforced plates, by Finite Elements. The reinforcing beams were placed paralel and orthogonal direction with respect to the junction line. Experimental results showed good agreement with numerical predictions.

Keywords: Análise Estatística Energética, Fator de Acoplamento, Placa Reforçada por Vigas, Fluxo de Energia

Statistical Energy Analisys, Coupling Loss Factor, Beam Reinforced Plates, Power Flow

COB1195 APLICAÇÃO DA ANÁLISE ESTATÍSTICA ENERGÉTICA PARA A PREDIÇÃO DOS NÍVEIS DE VIBRAÇÃO ESTRUTURAL E DE RUÍDO EM PLATAFORMAS OFFSHORE / APPLICATION OF STATISTICAL ENERGY ANALYSIS FOR NOISE AND VIBRATION LEVELS PREDICTION IN OFFSHORE PLATFORMS

L. C. de Souza, A. Lenzi e E. L. Sztajnbok

Depto. Eng. Mecânica, Universidade Federal de Santa Catarina - UFSC, CEP 88010-970 Florianópolis, Santa Catarina, Brasil

E-mail: lucianosouza@hotmail.com, Fone 048 - 234 0689, Fax 048 - 234 1519

High Noise and Vibration levels usually existent in offshore platforms can cause severe discomfort and stress problems to their occupants. The vibrations of large machines and equipaments transfere large amounts of vibratory energy to the main structure which is propagated throughout the platform generating unpleasant noise levels. This work describes the characteristics of a software, based on Statistical Energy Analysis - SEA, for predicting noise levels at the accommodation area. Results are compared to those measured in operating platforms. An anlysis of some related parameters is also presented.

Keywords: vibração, ruído, análise estatística energética, plataforma offshore, microstation

vibration, noise, statistical energy analysis, offshore plataform, microstation