Parametric study of composite beam-column connections using 3D finite element modelling

• Creation of a refined 3D numerical model to study the composite connection behavior.
• Validation of a 3D numerical model with previous obtained experimental results.
• Numerical analysis of the influence of some parameters in the connection’s stiffness.

This paper addresses the behaviour of composite beam-column connections that consist of concrete-filled steel tubes (CFTs), beams, bolts, endplates, and slabs. The composite connection under study was simulated with a tridimensional numerical model using the Diana software, which is based on the finite element method (FEM). A reference model was validated with previously obtained experimental results and was used as a reference for the parametric study. The parameters considered in the study included the bolt diameter, stud spacing, and slab reinforcement ratio. Analysis of the results led to the conclusion that changing a single parameter did not increase the connection stiffness because the failure was transferred to other structural elements in the connection. Instead, the connection dimensioning procedure should consider the entire set of parameters to guarantee the structure's security. Finally, the composite connection's behaviour is discussed in detail, and recommendations for the design are presented.