Effect of Analytical Parameters on the FE Analysis with the Smeared Crack Model of RC Beams Without Shear Reinforcement

Nowadays, 3D FE analysis is widely used as a more rational and accurate verification method for RC structures. For reliability, it is necessary to ensure that FEM can correctly evaluate the failure modes and loading capacity of the structure. FE analysis of reinforced concrete structures generally uses smeared crack models. This modeling approach is superior in terms of compatibility with FEM and low computational cost. The smeared crack concept was developed and validated assuming an averaged volume of around 20 cm square to represent concrete’s average behavior in a specific space. However, advanced analysis methods that integrate structural analysis and material analysis are becoming more common with fine discretization. Therefore, it is necessary to verify the accuracy of structural performance evaluation on these finer mesh size analysis cases. In this research, RC beams without shear reinforcement and the commonly used smeared crack model were the targets, and the effects of various analysis parameters on the behavior of shear failure were investigated. As a result, most of the analysis cases showed that the diagonal crack could not penetrate the compression zone due to the clear formation of a compression field. This effect was particularly noticeable at finer mesh sizes, and the ductility of the member was maintained. Subsequently, the shear capacity was overestimated. In addition, it was observed that the angle of the diagonal crack was influenced by the degree of bond between the concrete and the reinforcement.