Lateral Buckling of Braced Multistory Frames

An approximate theory of buckling for multistory frames having shear bracing in the form of a vertical truss or shear panels is presented. The effects of the shear stiffness of the bracing and of the flexural stiffness of the girder are included in deriving the governing equations. Both the symmetrical mode and the unsymmetrical or sidesway mode of buckling are considered. Solutions to the systems of governing equations are given in closed form for the case in which the frame and the loading have certain regular characteristics. These solutions lead to formulas for the required girder stiffness when the bracing stiffness, column sizes and axial loads are prescribed. A method of solution for the general or irregular case is also described.