GRADEVINAR, vol.69, no.9, pp.841-850, 2017 (SCI-Expanded)
In this study, two new functionals are derived based on Gateaux differential in order to analyse buckling of symmetric cross-ply laminated composite straight beams. The functional comprises four independent variables, i.e. deflection, rotation, shear force and bending moment for Timoshenko beam, and two independent variables, deflection and bending moment, for Euler-Bernoulli beam. The application possibilities and performance of the proposed mixed finite element formulation are presented on several numerical examples.