Effect of Rib Geometry in Steel-Concrete Composite Beams with Deep Profiled Sheeting

摘要

Presented are the results from a finite element model of steel-concrete composite beams with deep decks and a comparison with various analytical/design methods. Using a deck deeper than 80 mm are becoming popular with a desire for longer spanning capability and lower concrete volume. However, there are no design rules in either American or European design codes for using a deck deeper than 80 mm, as both codes limit the deck rib height to 75 and 85 mm, respectively for using the stud's capacity formula. Therefore, research is needed to establish the design stud capacity in beams with decks deeper than 80 mm. After extensive validation, the 3-D FE model is used for a parametric study with tests having decks deeper than 80 mm. The parameters include rib geometries, studs' layout and concrete slab reinforcements. The FE results showed that stud capacity with narrow and deep decks (100-150 mm) is about 70% of the conventional decking (60-80 mm deep). The stud capacities from the numerical results were compared to the predicted strengths from the design/theoretical models. While the equations from the concrete pull-out failure mode by Johnson and Yuan (Proc Inst Civ Eng Struct Build 128(3):252-263, 1998) gave reasonable predictions with a coefficient of variation as 11%, both EC4 and ANSI/AISC rules provided inaccurate and inconsistent predicted strengths. A generalised stud capacity formula should be developed in the design codes for decks deeper than 80 mm.