XFEM and Interface Element Models Applied to Fracture of Fiber Reinforced Concrete Beams

Marcello Congro¹; Cristian Mejia¹; Deane Roehl¹

¹ Tecgraf Institute - PUC-Rio

doi:10.20906/CPS/CILAMCE2017-0195

Resumo

Since the second half of the 20th Century, Fracture Mechanics is gaining strong relevance in Structural Engineering, more recently in numerical and probabilistic analyses regarding the opening of cracks in non-conventional reinforced concrete structures. Some applications include polymeric or natural fiber reinforcement. However, the study of these problems involves nonlinear effects with complex modeling, once the fracture process introduces discontinuities in the displacement field. Different approaches have been employed in order to analyze fracture paths, peak loads and deflections in a composite fiber reinforced concrete beam. In this study, numerical fracture analysis was carried out using two distinct finite elements (FEM) formulations: Interface Elements and Extended Finite Element Method (XFEM). Mixed-mode fracture behavior is considered. These numerical methodologies are based on a constitutive damage model, adjusted to experimental results of failure mechanism in a fiber reinforced concrete. The simulations reproduce experimental procedures reported in the literature by Marangon (2011), as the four-point bending test and the direct tensile test. In this respect, the joint study of which approaches has contributed to achieve results with good accuracy, validated against experimental procedures, and predicting the beam's fracture behavior under mixed-mode.

Palavras-chave: Fracture Mechanics; Extended Finite Element Method; Interface Elements; Numerical Analysis; Concrete Fracture; Composite Materials