مشخصات پژوهش

Using web-tapered members in long span frames is popular among steel designers for its structural performance and economic advantages. In order to adequately follow flexural stiffness and strength demands in such buildings, it has been found more desirable and cost-effective to change the tapering ratio of sections, element thicknesses and/or width along members. Such section changes can strongly affect structural behaviour and may cause more troubles whilst assessing the sway stability of frames. In this paper a closed form solution is proposed to deal with Multi-Segment Web-Tapered (MSWT) members consisting of any number of segments and possessing any column base connection rigidity. In this regard, any deformation except those that arise due to flexure are disregarded and an available K-Factor alongside its relevant lateral stiffness formula has been upgraded to account for MSWT features in member and frame instability evaluations. Some examples have been solved to validate the proposed formula in cases with different column base fixities, existence of leaning columns, and asymmetric gravity loading. Based on this study’s results, it is concluded that the proposed formula can be considered as a sound, reliable and versatile tool in the analysis and design processes of gabled frames composed of MSWT members.