An Efficient Approach into Finite Element Method for Lateral Buckling Analysis of Fiber-Metal Laminates Tapered I-Beams

In this paper, lateral stability analysis of fiber-metal laminated (FML) doubly-symmetric tapered I-beams with symmetrical lay-up for all section walls is perused by presenting a new finite element solution. Vlasov’s thin-walled beam theory is utilized to consider the bending–twisting coupling effect. Based on the classical lamination theory as well as the energy method, the total potential energy is derived for the flexural displacements and the twist angle. Using an auxiliary function, the variational formulation is then constructed only in terms of the twist angle. To precisely determine 4*4 elastic and buckling stiffness matrices, Hermitian cubic polynomial is applied as the shape functions into the resulting variational statement. The most beneficial feature of the present finite element model is to provide a two-node laminated I-beam element with a low number of degrees of freedom. Lateral buckling strength of thin-walled FML profile having varying I-section has been calculated for E-glass/epoxy as composite and aluminum as metal. The obtained results are compared with finite element solutions using ANSYS software and showed excellent agreement with them. Also, the effects of different consequential parameters such as fiber orientation, lay-up sequence, metal volume fraction, web tapering ratio, and transverse load height position on lateral stability resistance of fixed-free FML tapered I-beams subjected to uniformly distributed load are comprehensively investigated