Comparison of classical and refined beam models applied on isotropic and FG thin-walled beams in nonlinear buckling response

In this work, nonlinear buckling analysis of thin-walled beams by two different models is investigated: first one, developed by MUL2 group, based on Carrera Unified Formulation, and THINWALL v.16 beam model based on classical Euler-Bernoulli-Vlasov beam theory. In former, the refined beam theories are obtained on the basis of Taylor and Lagrange-type expansions. Latter is performed in framework of updated Lagrangian formulation adopting nonlinear displacement field of thin-walled cross-section. Isotropic and FG beams are referred to. It is observed that numerical results obtained by these methods match very well.