Stiffness Requirements for Shear Diaphragms Used for Stability Bracing of Slender Steel Beams

Abstract

The buckling resistance of steel I-beams can be increased by providing lateral bracing along the length of the beams by either cross-frames or diaphragms. Metal sheeting that is often used in steel buildings and bridge constructions to support the fresh concrete, acts like a shear diaphragm and provides continuous bracing to steel beams. An adequate bracing system must possess sufficient stiffness and strength. A computational study was conducted to investigate stiffness requirements of shear diaphragms used to brace slender steel I-beams. Both double and single symmetrical axis sections were studied. Beams that are braced by cross-frames in addition to diaphragms have also been investigated. Stiffness requirements have been proposed for shear diaphragms used to brace slender steel I-beams.