Slenderness ratio of telescopic cylinder-columns

The present paper deals with the effective slenderness ratio of telescopic cylinders as a longcolumn having different cross sections. Firstly, the slenderness ratio defined in the current standard for thetelescopic cylinders is discussed to point out some difficulties which arise when the ratio is applied to thecolumn having different cross sections. Secondly, a new effective slenderness ratio is proposed for columnshaving different cross sections by introducing a partial effective slenderness ratio. Finally, the proposedslenderness ratio is applied, for extending and development of discussion, to a two-staged column havingpiece-wise constant cross sections and a cylindrical column having linearly varying diameters.