Semi-supported steel shear walls (SSSW), whose steel plate is connected to secondary columns rather than main columns of the frame, have been considered as alternative steel shear walls to the traditional type. Many investigations have been made for proportionate designing of components of SSSW system. One of important issues in this regard is the out of plane buckling of the secondary columns. In this paper, the plastic theory of structures is utilized to find out the axial force distribution, along the compressive column. Then, using energy method, for an assumed shear wall with specific geometry and material and a given shear force, the maximum overturning moment that makes the compressive secondary column buckles, can be determined. Repeating this method, for various shear forces, makes it possible to draw some interaction curves between overturning moments and shear forces. These curves can be used to analyze and design of semi-supported steel shear walls.
