Numerical Modeling of Steel Fiber Reinforced Concrete Beam with Notched under Three-point Bending Test

This paper presents numerical modeling using the 3D nonlinear finite element method, which utilizes the multi-surface plasticity model. Steel-fiber reinforced concrete's strength, ductility enhancement, and mechanical behavior under tension are implemented inside the tension fracture model. The proposed model differentiated the contribution from concrete and steel fiber that resist the tensile force and later combined as one response of steel fiber reinforced concrete under tension using the superposition method. The contribution of the steel fiber that resists tension in the proposed model can have residual stresses, which correspond to the slip of the fiber embedded inside the concrete while maintaining its load-carrying capacity via the bond-slip friction between the concrete and the steel fiber. The proposed model is implemented inside an in-house 3D-NLFEA package. The model was verified with the available test result in the literature for SFRC with hooked-end and plain straight fiber. A comparison with another numerical result from the literature using ATENA is also presented to demonstrate the numerical model further. Differences in the SFRC mechanical behavior modeling between the 3D-NLFEA and ATENA are discussed thoroughly. From the comparisons, the 3D-NLFEA package with the proposed tension fracture model can reasonably predict the response of SFRC. For modeling the SFRC with plain straight fiber, only an adjustment on the tensile fracture energy for plain concrete is adopted.