Buckling analysis of castellated steel beams using beam elements

A study is undertaken to determine elastic critical moment of castellated beams. A beam element with warping degree of freedom is developed to study the effects of castellation on lateral tortional buckling. The concept of minimization of the total potential energy is used to derive the stiffness and geometric stiffness matrices. Section properties are calculated for the openings whereas the whole cross section properties are used for the remaining regions. Using this formulation, simply supported and cantilever columns and beam-columns are analyzed various loadings. It is found that the derived beam element generates comparable results with those from the literature. It is well known that if the aspect ratios of the holes are similar the LTB behavior will not be different. However, the present formulation can be used to study LTB of castellations with small and large openings.