Three-dimensional simulation of nonlinear response of reinforced concrete members subjected to impact loading

A triaxial failure criterion was applied with the theory of plasticity to model the behavior of reinforced concrete structures subjected to impact loading. The concrete nonlinearity, the cracking in the concrete elements, and the loading and unloading were simulated using an elastic-plastic fracture model. The influence of the loading rate on the concrete can readily be introduced by modifying the level of the yield and loading surfaces if the necessary data is available. In tension, a smeared crack model was used with a tension-softening model for the retained postcracking stresses. The reinforcing bars were represented by tensile stiffeners that were smeared in the appropriate direction over the element cross section. Verification of the analytical procedure was carried out using previously published results from scale model tests on a reinforced microconcrete beam and a portal frame, as well as from a test on a full-scale reinforced concrete beam. It was found that the maximum impact load, the propagation of the cracks, and the failure modes can be predicted with reasonable accuracy using the proposed approach. The approach can be used in the design of reinforced concrete structures subjected to impact loads.