Investigation on the dynamic failure characteristics of concrete slab based on mesoscopic simulation and energy conversion analysis

In this study, Continuous Discontinuous Element Method (CDEM) was employed to analyze the failure of concrete slab under drop-hammer impact at the mesoscopic level. Initially, simulation models of the impact system were established, and concrete slab models, including three-dimensional random aggregates, were generated. Mesoscopic simulations of concrete failure were then conducted by considering different variables, such as impact energy, slab size and the number of hammerheads. Corresponding drop hammer tests were used to validate the simulation results. Furthermore, an energy conversion formula for the dynamic failure of concrete slabs was derived, and the energy conversion process within the impact system was analyzed. The study also revealed the dynamic failure mechanisms of concrete slabs under various impact conditions. The research demonstrates that the simulation results are generally consistent with the impact tests. CDEM effectively investigates the impact characteristic and the energy conversion process of concrete slab failure. Under varying impact energies, slab sizes and hammerhead numbers, distinct differences in the failure characteristics of concrete-slab structure were observed. Increased impact energy accelerates the failure of concrete slabs, whereas larger concrete slab sizes inhibit crack propagation. The number of impact heads determines the initial crack position and its propagation path within the concrete slab. Moreover, the energy conversion process of the impact system significantly influences the failure behavior of the concrete slab. The effect of slab size on the energy utilization rate is greater than those of hammerhead number and impact speed.