Flexural strength of steel decks with square and rectangular holes: Numerical studies

Abstract Holes in steel roof decks are often provided to allow for the passage of services. Published information on structural properties and design methods of steel deck with holes is limited. To shed light on this topic, a numerical parametric study of the flexural strength of steel decks with single square and rectangular holes was performed. This paper presents results of the study. Nonlinear finite element deck models were developed in ANSYS and validated using published test results. Flexural strengths and load-deflection curves predicted by the developed models showed good agreement with the experimental data. The following parameters were varied in the study: deck type and thickness, hole width and length-to-width ratio, hole location along and across the deck span, and load type. Ultimate moment reductions due to the holes have been presented and discussed. The ultimate moments obtained numerically were compared with those predicted by the effective width and direct strength methods. Modifications of the direct strength method were proposed to allow for better predictions of the flexural strength of steel deck with holes. A method to account for the effects of hole location along and across deck span on the ultimate moment was also presented. The design methods predicted the simulation results well when the proposed design procedures were considered. It was shown that the direct strength method predictions for distortional buckling of solid decks depend on the compression-to-tension flange width ratio. The conservatism of the DSM predictions increases when the compression-to-tension flange width ratio increases.