Lateral buckling of thin-walled beam-column elements under combined axial and bending loads

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• 作者：Foudil Mohri ; Cherif Bouzerira ; Michel Potier-Ferry
• 关键词：Beam-column ; Finite element ; Non linear ; Open section ; Stability ; Thin-wall
• 刊名：Thin-Walled Structures
• 出版年：2008
• 出版时间：March 2008
• 年：2008
• 卷：46
• 期：3
• 页码：290-302
• 全文大小：540 K

文摘

Based on a non-linear stability model, analytical solutions are derived for simply supported beam-column elements with bi-symmetric I sections under combined bending and axial forces. An unique compact closed-form is used for some representative load cases needed in design. It includes first-order bending distribution, load height level, pre-buckling deflection effects and presence of axial loads. The proposed solutions are validated by recourse to non-linear FEM software where shell elements are used in mesh process. The agreement of the proposed solutions with bifurcations observed on non-linear equilibrium paths is good. It is proved that classical linear stability solutions underestimate the real resistance of such element in lateral buckling stability especially for I section with large flanges. Numerical study of incidence of axial forces on lateral buckling resistance of redundant beams is carried out. When axial displacements of a beam are prevented important tension axial forces are generated in the beam. This results in important reduction of displacements and for some sections, the beam behaviour becomes non-linear without any bifurcation.