Slenderness ratio of telescopic cylinder-columns

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