ABSTRACT
Steel columns of hollow cross-sections and simply supported at their ends are considered in the paper. Columns of such shapes are recently frequently proposed by architects in public utility buildings of various types. In this work authors present the comparatively simple procedure which can be used by designers of steel columns of such shapes. The value of critical force required in the procedure was derived for columns of variable cross section by means of Mathematica™ system. The closed formulae were obtained for a rod with a certain, predefined geometry being the surface of revolution. Critical forces obtained by means of derived formulae were compared with numerical solutions. To assess the compression resistance of considered rods the general Ayrton-Perry approach was applied and bow imperfection with assumed amplitude was used in the analysis. Examples inserted in the paper confirm the correctness and the effectiveness of the proposed procedure.
