The Transverse Stresses in Thin-Walled Beams and its Effect on Strength and Stability

Abstract

The transverse stresses are studied in thin-walled mono-symmetrical steel I beams. Equations are obtained to calculate these stresses in the three plates of the beam. The effect of these stresses on the beam strength has been analyzed. It is found that these transverse stresses in the flanges need to be considered carefully in strength checks at the supports and at the sections where concentrated loads act if the contact widths at the supports or at the loaded points are small.

There are two theories available at present for the stability of thin-walled beams. One is traditional, the other is a more recently presented newer theory. They give quite different buckling moments for mono-symmetrical simply supported beams under transverse loads. This paper presents a newly formulated buckling theory of thin-walled beams based on the general variational principle for stability of solid structures and the plate buckling theory in which the effect of the transverse stresses on the beam stability has been included. This new theory confirmed the traditional formula of the critical moment, but not the more recently presented newer one. The buckling analysis using ANSYS confirmed also the new theory presented in this paper.

Keywords

stability beam thin-walled members stress

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