FINITE ELEMENT MODELLING OF CRACKING IN FIBER- REINFORCED CONCRETE BEAMS

Resumo

In this paper, a fiber-reinforced concrete beam is modelled in the framework of Finite Element Method.
It is adopted three approaches, namely Smeared crack, Discrete crack and Damage models. The analyses are
conducted through commercial software DIANA FEA and an in-house computational routine. To do so, it was
selected an experimental data of concrete notched beam presented in literature to compare with the proposed
models. First, Smeared crack model with Crackband regularization technique was studied and compared with
Discrete crack model. The Discrete cracking approach was used to simulation and sought to reproduce the
experimental Force-CMOD curve considering the experimental cracking pattern of the specimens. To do so, it was
necessary to obtain mode I fracture energy (Gf), the tensile strength of the fiber-reinforced concrete (ft) and the
associated softening behavior. Numerical results show a convergence towards the experimental results. In parallel,
the Damage models with crack band, nonlocal integral and interfaces elements techniques are also used to simulate
the experimental structure. To do so, now it was necessary to obtain the maximum crack opening (wu), ft and the
associated softening behavior. They demonstrate similar results when compared to laboratory tests.