Stability Analysis of Cable-Stayed Rigid Frames

Abstract

The stability analysis of two-dimensional cable-stayed rigid frames containing a mixture of rigid and pin joints, may be conveniently performed on the computer to obtain the critical buckling load and its associated mode shape. The two-dimensional frame may contain a mixture of rigid and pin joints, as well as a mixture of members under combined bending and axial force and cables under axial force only. The primary state under the critical buckling load may be a deformed state by itself, to which the buckling mode shape is superimposed. The displacement method is used to establish the global stiffness matrix. The effects of the primary axial forces on the stiffness coefficients in bending and on the member equilibrium by their separate lines of action are both considered. The buckling load factor is obtained by raising the relative primary axial forces until the determinant of the global stiffness matrix becomes zero. Higher modes may be obtained by further increasing the relative primary axial forces.