Modeling one-dimensional tension stiffening of plain and fiber reinforced concrete with discrete cracks

In this paper, a mechanical model is developed to simulate the behavior of 1D plain reinforced concrete (RC) and fiber reinforced concrete (FRC) members subjected to uniaxial tension, considering the development of discrete cracks. The force bridged over the crack is a function of the crack width, fracture energy, and fiber volume. The model is formulated and based on the variational principle of the virtual work, it is more general than previous models and it can utilize any loading scheme, constitutive laws or boundary conditions. It is solved numerically using a special hybrid finite element method. It is validated by comparisons with available examples and test results. Results obtained by the model demonstrate its capabilities of simulating FRC members and incorporating the contribution of the fibers in bridging residual tensile forces over the cracks. The influence of the fiber volume on the global structural behavior of FRC members through the bridging forces in the cracks is discussed.