Numerical modelling of RC dapped-end beams with different reinforcement layouts

Dapped-end beams are widely used in bridge construction due to their structural efficiency and ease of assembly. These regions represent discontinuities, where assessing the stress state necessitates the use of Strut-and-Tie (S&T) models or nonlinear numerical analyses. This paper presents a numerical modelling study of dapped-end beams, validated against an experimental campaign conducted on specimens which differ in dimensions and reinforcement layout. The finite element analysis utilizes the latest formulations for material constitutive laws, focusing on 2D and 3D models and various approaches to modelling the interaction between concrete and reinforcing bars. The experimental data, which included load-displacement curves and failure modes, were compared with numerical results to assess the accuracy of each modelling approach. The study highlights the impact of using 2D versus 3D models and different reinforcement modelling approaches on the load-bearing capacity and crack patterns of beams, providing valuable insights into the most effective modelling strategies.