Modelling of concrete material behaviour with application to reinforced concrete beams subjected to impact

This report presents a finite element analysis of impact loading tests for reinforced concrete beams. The purpose of the work was to evaluate the ability of the chosen numerical method and material models to predict the material and structural response. The impact loading was carried out using a drop weight impacting a simply supported beam at mid-span. Four beams, reinforced with steel rebars and stirrups, were tested. The velocity of the drop-weight and the beam, the strain history of lower reinforcement bars and the acceleration history of the beam were registered and a high-speed film camera captured the crack development. The finite element analysis gave a different type of failure compared to the tests. In the test, the failure was mode I cracking combined with crushing in the impact zone, whereas in the simulators, the failure was mainly due to mode II cracking. Changes were made to the model and to the material data but the results from the test could not be reproduced. The conclusion is that the chosen concrete material model does not seem to be capable of correctly describing the problem, given the material properties and the numerical tool of analysis.