On the dynamic response of reinforced concrete beams subjected to drop weight impact

摘要

To improve the impact resistance of reinforced concrete structures, a detailed understanding of the dynamic response is required. This study investigates this impact resistance using experiments in combination with 3D non-linear finite element (FE) simulations. The experiments made use of high-speed photography and digital image correlation (DIC), while a damage-plasticity constitutive model for concrete was used in the FE simulations. Drop weight impact tests of simply supported reinforced beams made of plain concrete and fibre reinforced concrete were made, and it was shown that the addition of fibres reduced crack spacing, crack widths and midpoint deflections. For the FE approach, tetrahedral elements were shown to be well suited for capturing inclined shear cracks and the structural response obtained in experiments and analyses agreed very well. The FE analyses showed that the reinforcement strains were more localised for concrete with fibres, and hence predicted an increased risk of reinforcement rupture.