Numerical study on the impact performances of reinforced concrete beams: A mesoscopic simulation method

The failure of reinforced concrete (RC) members is closely associated with the mesoscopic structure of concrete. To describe the complicated failure process of RC beams subjected to impact loads accurately, a 3D mesoscopic simulation method considering the concrete heterogeneities was developed. At the meso-scale, the concrete was assumed to be composed of aggregate, mortar matrix and the interfacial transition zones (ITZ). In the simulation method, the strain rate effects for the three meso-components and steel bars were taken into account, and the web reinforcement was simply embedded into the plane concrete members without considering the bond-slip behavior. The mesoscopic simulation method was validated and verified by comparing the simulation results with Fujikake et al.'s test observations and macro-scale simulation results in terms of failure pattern, impact force and mid-span deflection. Moreover, the impact responses of the RC beams involving the acceleration and velocity distribution as well as the impact stress distribution were also investigated. Finally, based on the mesoscopic simulation method, the influences of stirrup ratio, hammer weight and span length on the impact behavior of RC beams were studied and discussed.