Longitudinal Stiffeners for Compression Members

Simplified methods based on buckling strength are developed for proportioning stiffening lips on thin flanges and intermediate stiffeners on thin sheet subjected to uniform compression. Symmetrical and unsymmetrical stiffeners and lips are considered. Buckling strengths are determined from the equivalent slenderness ratio formulas presented and column buckling equations. The radius of gyration of stiffener or lip required to provide essentially a hinge support for the flange or sheet at the stiffener is developed. Compression tests of thingage hat sections of aluminum alloy 6061-T6 provide information on the buckling strength and behavior of sections with lipped flanges. These and other previously published test data substantiate the equations developed for buckling of lipped flanges.