RESISTÊNCIA ÚLTIMA DE ESTRUTURAS DE NAVIOS SOB FLEXÃO (original) (raw)

The objective of this thesis is to develop a method for the evaluation of the behaviour of ship's strutures under bending moments, which includes not only the estimation of the ultimate moment support by the ship but also the pre and post collapse behaviour. The compression of plate elements is treated with special attention and dependence of the ultimate strength on the boundary conditions, slenderness, aspect ratio, initial imperfections and residual stresses is investigated. Regarding to stiffened plates under compression, the influence of different material properties in the plate and stiffener and different geometry of the stiffener is investigated. The results of the work on plates is also incorporated in the method of evaluation of the behaviour of stiffened plates. Five experiments on box girders under pure bending moments have been done in order to validated the method. Also they allow the study of residual stress relief and residual strength after collapse. These box girders have a geometry of typical ship's hulls so they may be taken as representative of them. Key-words: Box-girder tests, initial imperfections, longitudinal strength of ships, residual stresses, ultimate bending moment, ultimate strength of plates.