Finite element modeling and analysis of reinforced concrete beams with steel fiber and steel plate

In this study, a numerical analysis was carried out by using ANSYS finite element software to model and evaluate the structural behavior of full-size reinforced concrete (RC) beams having different properties. For this, a reference beam having a span length of 6.5 m was designed. Then, two cases were considered to enhance the structural performance of the RC beam. In the first case, the use of steel fiber in RC beam was taken account. Three steel fiber volume fractions (0.5, 1.0, and 2.0%) were investigated. In the second case, the bonding of steel plate to the tension face of the beam by adhesive resin was considered. Various thicknesses of steel plate (1, 2, and 3 mm) was utilized in this case. All beams were subjected to a three-point bending test. The nonlinear property was modeled for the concrete using three-dimensional (3D) solid element. The steel reinforcing bars were modeled as linkage elements with elasto-plastic behavior and perfect bond between concrete element and steel bar was assumed. The steel plate used for strengthening RC beam was modeled as a plane shell element connected to the lower concrete surface by using special contact surface between them. The steel fibers were considered as small units of reinforcement embedded in concrete based on the geometry of the concrete element. The efficiency of the current models was measured by comparing the results with previous experimental results. A good agreement was found between the model predictions for the load-deflection relation and experimental results. Besides, the use of steel plate for strengthening conventional RC beam significantly increased the ultimate load carrying capacity as well as the stiffness of the beam more than that of the steel fiber cases, especially when a steel plate thickness was chosen as 3 mm. Keywords: Finite element method, Reinforced concrete beam, Steel fiber, Steel plate, Strengthening.