FE Analysis of Steel Fiber Reinforced Concrete Beams Failing in Shear: Variable Engagement Model

This paper describes how a finite element model (FEM) is developed for the analysis of fiber reinforced concrete plane stress members that failed by the mode I fracture. The constitutive law is built on the variable engagement model where the behavior of a fiber composite is obtained by integration of its parts (fibers and concrete matrix) over the cracked surface. In developing the model in this way the formulation is made generally applicable to any type of steel fiber-cement based matrix and to fiber cocktails with any combination of fibers in the mix in any ratios. The model is demonstrated for a reactive powder concrete girder failing in shear using local and non-local modeling. The paper describes how the finite element formulation is shown to be capable of modeling the girder, with good accuracy observed for the global load versus displacement history and is shown to correctly capture the localized shear failure mechanism.