Numerical evaluation of reinforced concrete slabs with fixed support under impact load

Reinforced concrete (RC) structural members may be subjected to impact load besides quasi-static load or other dynamic loads like earthquake and wind loads in their service periods. Many research emphasized that although impact load acts on structural members for a short time, it caused considerable damage to these members or even collapses the whole structure. Thus, it becomes crucial to consider and accurately evaluate the impact load effect in the design process. The present study intends to introduce a finite element model (FEM) verified with the test data for the accurate evaluation of load-deflection behavior and damage patterns of the fixed supported RC slabs exposed to impact load. First, a nonlinear FEM including strain-rate effect for both concrete and steel reinforcement, and crack visualization algorithm has been established by using LS-DYNA software. Then, the dynamic responses obtained by the present FEM have been compared with the experimental data presented in a previous study existing in the literature and it is found that the present FEM yields accurate results for the RC slab subjected to impact load and it can be safely used in the design process. In the second part of the study, using the verified FEM, the effects of applied input impact energy, the application point of impact load, and hammer geometry on the dynamic responses and failure characteristics of the RC slabs exposed to the impact loading were investigated and interpreted in detail.