Assessing the applicability of a smeared crack approach for simulating the behaviour of concrete beams flexurally reinforced with GFRP bars and failing in shear

Abstract

Numerical simulation of beams failing in shear is still a challenge. With the scope of verifying the applicability of smeared crack approaches to simulate the behavior of reinforced concrete (RC) beams failing in shear, a set of concrete beams reinforced with longitudinal glass fiber reinforced polymer (GFRP) bars, experimentally tested up to their failure, and comprehensibly monitored, are numerically simulated. The simulations are carried out with a multi-directional fixed smeared crack model available in the FEMIX computer program that has several options for modeling the crack shear stress transfer, which is a critical aspect when simulating RC elements failing in shear. The predictive performance of the numerical simulations is assessed in term of load vs deflection, crack pattern at failure, concrete strains in critical shear regions, and moment-curvature relationship. The influence on the predictive performance of the following modeling aspects is also investigated: finite element mesh refinement; simulation of the crack shear stress transfer by using the classical shear retention factor and a crack shear-softening diagram; bond conditions between flexural reinforcement and surrounding concrete. The simulations carried out demonstrate that small dependence of the results on the finite element mesh refinement and adequate crack patterns can be obtained with refinement levels suitable for design purposes and taking into account the actual computer performances, as long as a crack shear-softening diagram is used. However, the predictive performance of the simulations depends significantly on the values adopted for the parameters that define this diagram, as demonstrated by the performed parametric studies.

Numerical assessment of the potential of fibre reinforced shotcrete for structural strengthening of underground masonry tunnels

“…By using the FEM-based model described in Section 2, it was already demonstrated that the FE mesh refinement has negligible influence of the results, in the design context of structural elements (Barros et al, 2021), as long as a minimum refinement is exceeded, which was assured in the present simulations.…”

“…2, which is defined from the ξ i and α i (i = 1 to 3) parameters, and from the mode I fracture energy, G I f . For assuring the results are independent of the FE mesh refinement (Barros et al, 2021), this fracture energy is dissipated in a characteristic length dependent on the geometry of the FE, herein designated by crack bandwidth (l b ), which, in the present approach, was considered as being equal to the square root of the IP. The crack sliding moduli (D cr t ) in Eq.…”

A state-of-the-art review on experimental investigation and finite element analysis on structural behaviour of fibre reinforced polymer reinforced concrete beams

“…One of the major causes of concrete structure deterioration is the corrosion of steel reinforcement. An alternative approach to addressing the corrosion problem in concrete structures is to use FRP reinforcement instead of steel reinforcement [ 12 , 13 ]. FRP reinforcement shows potential structural behaviour because of its low magnetic susceptibility, high strength-to-weight ratio, and resilience to corrosion.…”

Modelling The Behavior Of I-Shape Concrete Beams Reinforced With Fibers And Prestressed Steel And Gfrp Bars

“…al. (2021) [15] demonstrated that a multidirectional fixed smeared crack model (MDFSCM) can accurately predict the relevant behavioral features of this type of structural element, as long as a crack shear softening law is used.…”

“…The FEMIX computer program incorporates a MDFSCM [15], which allows for the consideration of shear retention concepts, including constant values or dependence on crack opening, as well as the use of crack shear softening diagrams.…”