Finite element modelling approach for precast reinforced concrete beam-to-column connections under cyclic loading

In this paper, a finite element modelling approach is developed for the analysis of the cyclic behavior of precast beam-to-column connections. In particular, the modelling takes into account the compression-softening of concrete, the bond-slip effect in the critical regions and the representation of the post-cast concrete interface. A newly developed softened damage-plasticity model, which can reproduce the typical cyclic behavior of reinforced concrete, is adopted for concrete. Meanwhile, to reflect the significant bond-slip effect between concrete and reinforcement bars, the M-P stress-strain model is modified to account for the slippage by assuming the bar strain is the sum of the bar deformation and the slip, while the anchorage slip is theoretically derived and validated through benchmarking the pull-out tests. Additionally, a concrete layer between the precast concrete and the cast-in-situ concrete is incorporated to reflect the features of the interface. The proposed numerical modelling approach is validated through simulation of both interior and exterior precast beam-to-column connection tests. The validated models are subsequently employed to investigate the influences of key factors such as the compression-softening and the bond-slip effect on the analysis of the cyclic behavior of the precast beam-to-column connections. Results demonstrate that the proposed model is capable of reproducing the typical behavior of precast beam-to-column connections and can serve as an effective tool for the seismic performance analysis and investigation of design parameters of precast connections.