Strength Requirements for Shear Diaphragms Used for Stability Bracing of Steel Beams

Light gage metal sheeting is often used in steel building and bridge industries as concrete deck formwork. Besides providing support to the fresh concrete, sheeting acts like a shear diaphragm and provides continuous warping restraint to the top flanges of beams that they are attached to. Strength requirements of shear diaphragms bracing steel beams are not well established. A computational study was conducted to investigate the bracing behavior of shear diaphragms used to brace stocky and slender beams. This paper focuses on developing strength requirements for end and sidelap fasteners that connect deck sheets to structural members at the ends of the sheets and to each other at sidelap seams, respectively; and present results for stocky beams. To the best of the authors' knowledge this study is the first study that quantifies the stability induced fastener forces in sidelap fasteners. Doubly symmetric sections were considered. The effects of deck width and number of end and sidelap fasteners on brace forces were investigated. Expressions were developed to estimate the stability induced brace forces in end and sidelap fasteners.

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