Mohsen Bambaeechee - Ph.D. Student, Ferdowsi University of Mashhad

In this paper, a new exact formulation for calculating the elastic buckling load of semi-rigid steel frames withtapered columns will be obtained. The presented methodology is based on the precise solution of the governingdifferential equations for buckling of the uniform and non-uniform frames. Then, the effects of the non-prismaticmembers, with a parabolic stiffness variation, flexibility of connections, and lateral bracing on the buckling lengthfactor and corresponding critical load of a portal frame will be investigated parametrically. Results show thecombined effect of aforenamed parameter on the critical buckling load and corresponding equivalent bucklinglength factor of portal steel frames is very significant.

Buckling analysis, Tapered columns, Semi-rigid connections, Steel frames, Buckling length factor, Critical load