A failure theory for buckling of thin-walled RC compression members

Failure patterns arising out of instability of thin-walled axially and eccentrically loaded RC columns with channel cross section are identified and are presented. The characteristic load-lateral deflection interaction (P versus lateral displacement) of basic mechanisms are derived for reinforced concrete on the basis of the rigid plastic theory. Both isotropic and orthotropic reinforcement patterns are covered. The structural failure mechanisms are derived from the basic plate mechanisms such that they satisfy equilibrium and compatibility criteria. Collapse curve (load shedding curve) is drawn. The post buckling ultimate load is predicted, corresponding to characteristic deflection defined by a limiting curvature. Eccentrically loaded columns with positive eccentricity (away from centroid in the open side) are considered. However, the study is limited to columns with hinged end supports only.