Numerical evaluation of impact resistance of reinforced concrete walls

Reinforced concrete(RC) structures are occasionally subjected to accidental impact during service, which can cause economic losses and casualties. Most previous research on the impact resistance of RC structures has focused on beams, columns, and slabs except walls. Thus, it is necessary to study the impact response and resistance performance of essential RC walls with high resistance requirements, such as critical shear walls, important structures, and vital protective structures of high-rise buildings in earthquake and mountainous areas under low-speed impact. This research verified the finite element model (FEM) through pendulum impact experiments on RC walls (with an impact mass of 2 tons) firstly, then proposed the damage assessment parameters of the RC wall, and analysed the impact response mechanism and resistance performance of RC walls with several reinforcement ratios under different impact loads. The research results indicate that the impact effect on the wall must consider the different value (D-value) between local and global deformation. The impact load significantly influences the peak impact force and the displacement of the RC wall. The mass affects the RC wall's global residual deflection. At the same time, the velocity significantly influences local displacement, and correspondingly, the RC wall is more prone to local damage with high velocity. Thickness, the concrete fc, and the reinforcement ratio affect the impact resistance of the RC wall. The thicker wall can cause a shorter impact duration, and milder concrete damage, but the smaller rebar stress. The larger fc will bring greater rebar stress and milder concrete damage. A high reinforcement ratio will increase the impact force platform value and the RC wall's concrete damaged ratio but will reduce the plastic strain of the rebars.