Ultimate capacity prediction of RC and SFRC beams with low shear span-depth ratio using NLFEA and inverse analysis

In this study, the capacity and ultimate behavior of Reinforced Concrete (RC) and Steel Fiber Reinforced Concrete (SFRC) beams are evaluated. Nonlinear Finite Element Analysis (NLFEA) and the inverse analysis technique were used to model its structural response using the ATENA finite element software. The smeared crack approach, the crack band model, and advanced constitutive models were used to reproduce concrete fracture. The analyzed beams were subjected to rupture in a four-point bending test setup. The relationship between the shear span and the depth of the beams was 1.5. Four scenarios were analyzed, RC beams with and without stirrups, and SFRC beams without stirrups with volumes of 0.57% and 0.76%. The results obtained in the modeling are discussed in terms of the ability of the models to numerically reproduce the relationships: load versus displacement, load versus strain, crack patterns, and failure modes. The analysis techniques allowed to reproduce the experimental response of the beams with good agreement. They show great potential to solve structural engineering problems