Two-dimensional FE model for evaluation of composite beams, I: Formulation and validation

This paper develops a two-dimensional finite element model for composite beams, based on the use of the commercial package ANSYS. Different degrees of continuity can be taken into account, permitting the investigation of systems ranging from simply-supported to fully-continuous. Beams with either full or partial shear connection can be considered, as well as different slab typologies. The model represents the behaviour of all components of the composite arrangement, based on the best available current understanding, including the reinforcing bars (considering the tension-stiffening effect), the load–slip characteristic of the shear connectors, and the key components of the beam to column connection. In addition, material nonlinearity for all components is taken into account. The model has been fully verified by extensive comparisons against experimental and numerical results and it has been demonstrated that it is suitable for comprehensive parametric studies of the behaviour of composite beams. A sensitivity study focusing on both the required and the available rotation capacities and their importance for moment redistribution in semi-continuous composite beams is presented in the companion paper.