Nonlinear finite-element analysis for predicting the cyclic behavior of UHPC shear walls reinforced with FRP and steel bars

The paper presents a numerical investigation of the cyclic behavior of ultra-high-performance concrete (UHPC) shear walls with hybrid reinforcement of fiber-reinforced polymer (FRP) and steel bars. The concrete damage plasticity (CDP) model in ABAQUS was used to establish the finite-element analysis (FEA) model. The numerical results were compared to the experimental data of six UHPC shear walls in terms of damage pattern, hysteretic response, and strain distribution. The results demonstrate that the established FEA model could predict the cyclic behavior of the UHPC shear walls with an acceptable level of accuracy. A comprehensive parametric study was further conducted to investigate the influence of carbon fiber-reinforced polymer (CFRP) bars and FRP type on the cyclic behavior of UHPC shear walls. The authors suggest that CFRP bars should be used in the boundary element to improve the effectiveness of the CFRP bars. The authors suggest using a replacement ratio of CFRP bars in the boundary element of 33.3%similar to 66.7% to keep a balance between the self-centering and energydissipation capacity of the UHPC shear walls. Based on the simulation results, the UHPC shear walls with hybrid reinforcement of GFRP (glass fiber-reinforced polymer) and steel bars achieved favorable self-centering capacity while maintaining good energy-dissipation capacity.