Ultimate behaviour of high-yielding low-hardening aluminium alloy I-beams

The work herein presented is devoted to the prediction of the ultimate response of high-yielding low-hardening aluminium alloy beams subjected to a moment gradient. To this scope, a wide parametric analysis has been performed by the ABAQUS computer program to investigate the response parameters characterising the ultimate behaviour of I-beams. The parameters affecting the ultimate performances of aluminium alloy I-beams subject to local buckling under non-uniform bending are the flange slenderness, the flange-to-web slenderness ratio and the non-dimensional shear length. The flange slenderness parameter is directly related to the occurrence of local buckling either in the elastic or in the plastic range. The flange-to-web slenderness ratio accounts for the interactive buckling of the plate elements constituting the member section. The non-dimensional shear length accounts for the longitudinal stress gradient due to non-uniform bending. These non-dimensional parameters define entirely the geometry of the three-point bending scheme usually adopted for evaluating the rotation capacity of metal members. The results of the parametric analyses are expressed by the moment-rotation curves whose response parameters are the subject of empirical formulations. The final goal is the setting up of formulations to predicting both the maximum bending resistance and the rotation capacity of aluminium beams made of high-yielding low-hardening alloys.