Modelagem numérica de ligações viga-coluna em aço sob momento fletor e força normal.

Abstract

The joints develop a fundamental role in the global behaviour of steel structures. Several researches are being developed to understand the real behaviour of a joint and its influence in the global frame capacity and beam-to-column joints of the steel´s buildings. Nowadays, the Brazilian Code of the Steel Portal Frame Design, NBR 8800, considers the joint behaviour between two extreme situations: rigid, where any rotations don´t occur between the connected members, transfering substantial bending moments, and also shear and axial forces; or pinned, its characterised by almost free rotation movement between the connected elements that prevents the transmission of bending moments. However, some actual codes of the steel structures project, consider that the joints present an intermediate behaviour, in other words, semi-rigid, that may be subjected to a combination of bending moment and axial force. But, these codes don´t consider the presence of axial force (tension and/ or compression). A single empirical limitation of 5% of the beam s plastic axial capacity is the only enforced provision in Eurocode 3. This filosofy design is based on components method, for joint capacity evaluation and its classification concerning the joint rotation stiffness. This component method is based on mechanical models (spring model) created by an association of rigids and flexible joints components represented by a translacional spring. The objective of this present work is describing some results of flush endplate semi-rigids beam-to-column joints obtained across finite elements method and geometric and material non-linear analises. These consider the main parameters that influence the components behaviour about the stress and deformation distribution.