As ligações semirrígidas na análise avançada com zona plástica de portais planos de aço

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

In this work, the development of the Plastic-Zones Advanced Analysis of plane steel portals is studied, now including the connections effect. Firstly, this analysis is defined as inelastic second-order which capture the plasticity spread by slice technique and includes the Main Aspects as geometric (out-of-straight and out-of-plumb) and physical imperfections (residual stress). The connection effect is introduced, with bibliographic review ranging from history, properties, types, up to moment-rotation behavioral models (M-θ). A new connections model called Bi-linear Rigidity (BLR) is proposed. This model is applied in some analysis and allows the M-θ approaching by analogy. The numerical FE formulation with one end-connection and a new parameter called connections own-rotation index η, are presented. This influence of this index on formulation, values, changes and its effects on analysis are shown. The Axial Force Iterative Integration (AFII), that is a necessary task when section yielding happens, is adjusted and employed. The effect of plastic geometric centers move is studied, which arrived to plastic behaviors not covered in general literature. The computer implementation provides several connection models study, including the proposed one. Also are treated: how to define the connection rotation, the M-θ following path, and the non-linear cases of this graph control. There are analysis of beam, column and portals examples, at elastic and inelastic range, with non-linear and linear connections behavior, validating the contributions of this work. Further, the study defines the limiting geometric configuration as the one which brings the least limit load to design of the plane portal with connections. The Initial Configuration Theorem proposal validity is stated, as there are some cases where the found limit load doesnt modify because of initial imperfect geometry changes. Even in this situation, it is assured that the inelastic deformed shape can define this limiting configuration. When in doubt, simple tips (corollary) and a design rules for Advanced Analysis including semi-rigid connections are provided.

ASSUNTO(S)

ligações metálicas construcao civil métodos numéricos aço - estruturas

ACESSO AO ARTIGO

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