Numerical investigation of reinforced concrete beams under impact loading: Fid-Bau Portal

Numerical investigation of reinforced concrete beams under impact loading

Dhiman, Prince / Kumar, Vimal

Designing reinforced concrete (RC) beams for buildings to withstand impact loads is a complex task as its behaviour under impact is not known. Various methods, including analytical models, experimental testing and numerical analyses, have been employed effectively to understand the behaviour of RC beams under impact loading. The research employed a combination of numerical analysis using ABAQUS/Explicit and validation against experimental data. The RC beam configuration consisted of a 100 × 150 mm cross-section and a span length of 1800 mm, with varying shear reinforcement of 0.92%, 1.15% and 1.32%. To simulate impact loading, a free-falling drop-weight with a mass of 101.354 kg was used to strike the specimens at mid-span from heights of 0.65 m, 1 m and 1.5 m. Measurements included recording the impact load time history, reaction forces at the supports and displacement at the centre node of the beam. The failure pattern of the beam in the impact zone was analysed by comparing crack patterns and scabs with the impact load history. It was observed that higher shear capacity in the beam allows it to resist impact forces through spalling without significant deformation, leading to localised failure response. It was observed that under fixed boundary conditions, the peak impact force was 20% higher compared to hinged beams at a smaller drop height. With increasing the shear reinforcement ratio, the maximum mid-span displacement was found to be decreased by nearly 15–40% for the drop height ranging from 0.65 to 1.5 m. Additionally, for higher impact velocities, the fixed beams exhibited reduced mid-span displacement by 30–45% compared to beams impacted with lower velocities.