Abstract
In general, transition in the mode of failure from flexure failure at the static loading to shear failure at low velocity impact in reinforced concrete (RC) beams has been reported in the literature. To quantify the above-mentioned statement, a drop-weight impact test program was carried out on RC beams. The test results showed that no shear failure has been occurred under impact loading in statically flexure-critical beams (i.e., shear to bending resistance ration greater than one) however with increasing drop-heights more localized failure with extensive concrete crushing at the impact region was observed. Impact interface (i.e., direct impact or with some interface such as steel or plywood plate in between impactor and beam) could be one reason that the change in failure mode has not been observed in the current test program. To simulate the structural impact response in details, a three-dimensional nonlinear finite element (FE) model was also developed. Numerical results agreed well with the test results obtained from current test program and also from the literature. Finally, the numerical model was used to conduct parametric studies to evaluate the effects of design parameters (e.g., ratio of beam- mass to impactor-mass, longitudinal reinforcement ratio, compressive strength of concrete and boundary conditions etc.) on impact responses and failure modes.