Experimental analysis of a reduced size offshore structure

Abstract

The behaviour of a truss structure system, with straight cylindrical members, similar to those used in some type of offshore platforms is studied experimentally. Based on the similitude criteria and on available facilities a model is designed in order to simulate approximately an actual system, with a geometrical scale 1:lOO.The tests are performed in a wave channel under free vibration and subsequel tly under the action of regular waves, Conclusions are reached concerning the dynamical characteristics of the system, the behaviour and magnitude of the response. The data are compared with the results of analysis by computer using relatively standard techniques.sults are compared with an analysis made by computer under the general design atitu des and conclusions are reached concerning the dynamic characteristics of the system, the behaviour and magnitude of the response.The experimental phase o f the work was made at "Instituto de Pesquisas Hidrovizrias (INPH)", in Rio de Janeiro. The Physical Model Site and ChannelThe tests were accomplished in a regu lar wave channel, 45 . O m long by 0.8m wide, with a maximum depth of 1.40 m. The maximum workable frequency of the wave generator is 1.0 hertz. This became a serious limitation since there were many noises around this frequency which might have dis figured the true response. IntroductionModel