Analytical GNI Analysis for Lateral-torsional Behavior of Thin-walled Beams with Doubly-symmetric I-Sections

In this paper elastic lateral-torsional behavior of simple beams is discussed. The motivation the presented research observation that classic analytical prediction and finite element are, typically, considerably different, when second-order nonlinear with initial imperfections analyzed. order to understand explain observed differences, a novel solution for geometrically analysis geometric imperfection. derived doubly-symmetric cross-sections, but novelty it takes into consideration changing geometry as load increasing. most important steps derivations are summarized, resulted formulae briefly Numerical studies performed, too: results new compared those from shell analysis. suggest able capture elements behavior. By numerical results, proved solutions necessarily different obtained by incremental-iterative procedures.