The Influence of the Chord Axial Load on the Resistance of RHS 'T' Joints with Axially Loaded Braces: A Parametric Study

摘要

The intensive worldwide use of rectangular hollow sections (RHS) structural elements, mainly due to its associated aesthetical and structural advantages, led designers to be focused on the technologic and design aspects of these structures. Consequently, the accuracy of the adopted design methods is of major importance both under the economical and safety points of view. Recent studies of connections in RHS structures pointed out for further research needs, especially for some particular geometries. This is particularly significant when the failure mode changes and the prediction of the failure load may be unsafe or uneconomical. In this paper a numerical based parametric study performed for the analysis of a "T" connection configuration where both the chord and the brace are made of RHS sections is presented. The connection was submitted to an incremental tension axial load in the brace up to failure while the chord was submitted to different levels of constant axial load, in tension or in compression. This task was repeated for different brace to chord width ratios and chord thicknesses, keeping the material properties constant. A critical analysis of the results focusing on the influence of the considered parameters for the connection behaviour is presented, with an emphasis on its resistance, elastic stiffness and membrane stiffness. In addition, the numerical results for the resistance of the connection are compared to deformation limits proposed in the literature to assess the connection resistance, and to the plasticity based results from Eurocode 3.