The Effect of Rounded Corners in the Moment Resistance of Steel Shuttering of Composite Slabs

Resumo

The objective of this paper is to analyze the influence of modeling rounded corners on the bending
moment resistance of steel formworks used in composite slabs. The Finite Strip Method (FSM), as well as the
constrained Finite Strip Method (cFSM) were implemented via the software CUFSM for trapezoidal cross-sections
to predict the bending moment resistance with the Direct Strength Method. The FSM was used to determine the
critical loads and the cFSM served to identify distinct buckling modes for signature curves without unique minima.
Five different steel sheet geometries were analyzed - four commercially available sections and one extracted from
the literature. Based on these, 4 additional geometries with no intermediate stiffeners and 5 with straight-line
models were designed. In total, this study investigated 5 and 9 cross-sections with straight-line and rounded corner
models, respectively. Results show a slight influence of the corners on the critical moment of local buckling, with
straight-line models reducing this value, as well as increasing the distortional critical moment. Overall, the
difference between the cFSM and the FSM decreases for the local mode when considering rounded corner models
with stiffeners and for the distortional mode when using straight-line models with stiffeners.