Lateral Torsional Buckling of doubly symmetric web-tapered I beams, a numerical investigation.
Abdelrahmane B.BENYAMINA Abdelkader SAOULA
AbstractThe elastic lateral torsional buckling behaviour of doubly symmetric web tapered thin-walled beams is investigated in this work. For the purpose, a non-linear model is developed in large torsion context according to a new kinematics proposed model. Firstly, the elastic equilibrium governing equations are carried out from the stationary condition. Secondly, a numerical model based on Ritz's method is investigated for the lateral buckling stability of tapered thin-walled beams with doubly symetric cross-sections and simply supported boundary conditions. Total potential energy is derived for an elastic behavior from strain energy and work of the applied loads. The effects load eccentricities is considered in the study. The lateral-torsional equilibrium equations and the associated boundary conditions are obtained from the stationary condition. In presence of tapering, all stiffness coefficients are not constant. The Ritz's approximation is then used to solve the differential equations of tapered thin-walled beam with variable geometric parameters. The lateral buckling loads are determined by solving the eigenvalue problem of the obtained algebraic system. Several numerical examples of tapered thin-walled beams are presented to investigate the accuracy and the efficiency of the method. The obtained results are compared with finite element solutions using ABAQUS software and other available numerical approaches. It is observed that suggested method can be applied to stability of beams with constant cross-sections as well as tapered beams.