Effect of Bracing Stiffness on Stability of Unbraced Frames
Nazzal S. Armouti, Bassel J. Hanayneh

The effect of bracing stiffness on unbraced frames is evaluated. A single bay-one story frame having a span of 6 m and height of 4 m laterally supported by a spring (elastic support) at its joint is investigated. The frame stability is evaluated under various spring stiffness levels. It has been found that increasing lateral support stiffness increases the critical load to a point where spring stiffness reaches a threshold value to prevent the formation of the first buckling mode and triggers the second buckling mode without providing the frame with full lateral support. A two-bay two-floor frame laterally braced by shear wall is also investigated. It has been also found that providing unbraced frames with lateral supports with enough stiffness can convert the sway mode of buckling to non-sway mode of buckling which is a big advantage in the design of steel frames.

Full Text: PDF     DOI: 10.15640/jea.v7n2a11