Numerical Simulation of Responses and Failure Modes of Reinforced Concrete Beams under Drop-Weight Impact Loadings

Reinforced concrete structural members subjected to impact loads behave quite differently as compared to those subjected to quasi-static loading, with their failure mode becoming more complex.In this work, by introducing the strain rate effect of reinforcement in the trilinear model of the reinforcement, we simulated the structural responses of reinforced concrete beams under different impact loadings based on the dynamic analysis module of ABAQUS.The curves of impact-time and mid-point deflection-time were observed to agree well with those from the experiments.Based on this model, we simulated the responses of beams with the reinforcement ratios of 2.56%, 2.66%, and 2.76%, respectively.The comparison shows that the bearing capacity and deformation resistance of the beams increased with the increase of the reinforcement ratios; the enhancement effect of the reinforcement ratio weakens gradually as the impact velocity increases; when the impact velocity is 4.85 m/s, the reinforcement ratios have slight effect on the failure mode of beam at low impact velocities; in addition, when the impact velocity is higher than 4.85 m/s, the failure mode changes from shear failure to bending failure with the decrease of the reinforcement ratio.