A meso-scale analysis method for the simulation of nonlinear damage and failure behavior of reinforced concrete members

Based on the meso-mechanical analysis model of concrete material, a meso-scale numerical approach is developed for the simulation of failure behavior and nonlinear mechanical properties of reinforced concrete members. The present meso-mechanical approach, i.e. so-called the meso-element equivalent method, is capable of capturing the important characteristic of concrete heterogeneity. Two reinforced concrete columns of different sizes subjected to uniaxial compression is simulated using both a macro-scale homogeneous and a meso-scale heterogeneous model to illustrate the rationality of the meso-scale approach. In the simulations, perfect bond between concrete and reinforcing steel is assumed. The meso-scale simulation results are compared with the macro-scale results as well as the experimental observations. Results of the simulation at the meso-scale are in good agreement with experiments in terms of the failure patterns and the global mechanical properties, which demonstrate the rationality and accuracy of the present meso-mechanical approach. The present meso-scale approach can well simulate not only the macroscopic mechanical properties of the two reinforced concrete columns but also their failure process, such as the buckling behavior of the longitudinal reinforcement, the necking fracture of the stirrups, the broken positions of concrete, etc. Besides that it can be concluded from the numerical results that the present meso-mechanical approach can be extended to investigate the size effect in reinforced concrete members.