Numerical simulation of concrete beams - a principal study

A theoretical investigation has been performed on reinforced concrete beams subjected to air blast loading. The investigation involved numerical simulations with the use of Autodyn 3D and the purpose was among others to study deformations, failure modes, support reactions and cracking. A future goal is to have the ability to make predictions of the protective level of a structure subjected to large dynamic loads. The RHT material model was primarily used for the concrete but also the Drucker-Prager model was used as a comparison. Parameters such as flow rules for the concrete, the influence of meshing, strain rate dependence and modelling of the reinforcement were considered. The results from this investigation show the abilities to simulate the dynamic response of dynamically loaded concrete beams. Furthermore, the results show that the mesh influenced the shear failure of the beams for the used element sizes and material models. A continuation of this investigation should focus on implementation of a modified model for the tensile fracture of concrete, which can be used in combination with the RHT model. In this investigation, the reinforcement was not allowed any slip relative to the concrete elements. This, future work should involve theoretical studies on the bond slip relationships between rebars and the concrete. It is also of interest to study the dynamic behaviour of beams consisting of high strength concrete and with different amounts of tensile reinforcement.