MODE INTERACTION IN NON-LINEAR MODELS FOR STEEL STRUCTURAL JOINTS

摘要

This paper presents and discusses non-linear equivalent elastic models that reproduce the behaviour of steel joints loaded in bending. In these models, each substitute sub-system for an elastic-plastic spring corresponds to a critical load of the global system, each arising at different load (moment) levels along the fundamental equilibrium path. It is shown that these modes present a highly interactive behaviour, resulting in a cascade of secondary bifurcations that yield a broken line with reducing stiffness, effectively reproducing the original response of the non-linear elastic-plastic joint model.