Numerical Modeling of the Elastoplastic Flexural Response of Ultrahigh Performance of Fiber Reinforced Concrete (UHPFRC) using the XFEM Fracture Model

Resumo

Recently, several experimental and numerical models have been carried out to investigate the
mechanical behavior of fiber-reinforced concrete (FRC), especially concerning their flexural response to
structural applications. Modern developments regarding these materials involve using ultrahigh performance
fiber-reinforced concrete (UHPFRC) in strengthening layers or jackets. This particular type of FRC is a
relatively new construction material with excellent mechanical properties and a crack propagation control.
However, for the structural applications and design, it is necessary to carry out direct tensile and bending tests to
obtain the tensile stress-strain behavior and the flexural response of the composite. In this sense, this paper
proposes the elastoplastic numerical modeling of the mechanical behavior of UHPFRC, including the fracture
evolution analysis using the Extended Finite Element Method (XFEM). Mixed-mode fracture behavior is
considered. The finite element models reproduce a four-point bending test reported in the literature by
Lampropoulos et al. (2021). The results show that the concrete damage plasticity constitutive model can
efficiently predict the load-displacement behavior since the load capacity ranges present a good agreement with
the experimental reference. Moreover, it is possible to predict the fracture path of the beam in a mixed mode
based on the application of the XFEM model.