Batten plates effectiveness on the flexural and lateral - torsional buckling of steel I members

A way of mitigating the negative effects of flexural buckling and lateral torsional buckling (LTB) is the use of batten plates. Batten plates, at appropriate locations along the member are welded to the flanges thus resulting in an increase of flexural and LTB resistance.The aim of this paper is to investigate their effectiveness and to find theirs optimum position along the member in regard to the before mentioned buckling phenomena.First the effectiveness of batten plates on flexural buckling of I columns (pin ended columns) is investigated. A comprehensive study of different configurations and positions of batten plates together with different member sizes is carried out. Batten plates effectiveness is assessed through the elastic critical force of the member (Ncr) which is calculated analytically using a novel simplified expression.In the case of LTB the same approach is followed. Member sizes together with the batten plates configurations and locations are varied and elastic critical lateral torsional buckling moment (Mcr) is calculated. Only uniform bending of a simple beam is analysed.As a result of this study optimum positions of the batten plates in the cases of flexural and LTB are identified. Batten plates, depending on their width and thickness, can increase the Ncr from 7 % up to 50%. Theirs effectiveness is more pronounced in the case of LTB where this increase can be significantly more.Although an increase in Ncr or Mcr does not necessarily mean the same increase in member resistance the obtained results indicate that batten plates could be a good and cost effective way of increasing the flexural and LTB resistance of I members.This paper is meant to be a stepping stone towards further numerical and experimental investigations