Comportamento estrutural de colunas de seção transversal cruciforme

Abstract

Cross-sections where the midlines of the plate elements converge at a single point, such as in cruciform sections, are highly susceptible to torsional instability phenomena due to their low torsional stiffness. The limited amount of research in the literature on the behavior of columns with this type of cross-section highlights the need for further investigations to fully understand the instability phenomena affecting these structural elements and to enable the development of more accurate design methods, particularly in the case of columns made of stainless steel. Therefore, this study presents a numerical analysis using the finite element method of the behavior of fixed-ended cruciform columns made of carbon steel and stainless steel and prone to failure by torsional buckling. Essential theoretical foundations for understanding the studied problem are initially provided. Subsequently, the numerical model developed in the Abaqus software is described in detail, and comparisons with experimental results available in the literature are made to validate its accuracy and reliability. Furthermore, buckling and post-buckling analyses were carried out to better understand the instability phenomena governing failure in these structural elements. In addition, a parametric analysis assessed the applicability of the Eurocode 3 design method, which was found to be safe but overly conservative. An alternative buckling curve is proposed for columns made of carbon steel, whereas for stainless steel columns, the lambda method has demonstrated greater efficiency.