SLAB BEHAVIOR IN COMPOSITE BEAMS AT OPENINGS .1. ANALYSIS

The load-carrying mechanism in concrete slabs of composite beams at web holes is studied. Using a truss analogy, the shear studs in the hole region are considered as vertical tension-carrying members, and inclined struts in the concrete are considered to act between bearing zones at the heads of the studs and at their bases at the steel beam flange. The structural action between the concrete slab and the shear connectors is clearly identified, and rational truss idealizations for determination of the slab shear-carrying capacity are developed. This approach relates the shear capacity to the location of studs, and three idealizations are used to provide solutions for three typical stud configurations. In this way, the ultimate resistance of composite beams containing large web holes is estimated. Both solid slabs and ribbed steel deck-supported slabs are considered.