Shape memory alloy (SMA) is a smart material that is currently used in reinforced concrete members. This preliminary research aims to numerically investigate the role of diameter and percentage of SMA as the main reinforcement of concrete beam in increasing stiffness and reduction of residual displacement. To do so, eight beams with same geometry and boundary condition reinforced with superelastic SMA under two cycle of four‐point bending loading in Ansys APDL have been simulated. Results showed that enhancement of ratio of SMA in the beams will reduce residual displacement and increase stiffness of the beams. Furthermore, for beams with same percentage of SMA bars, more number of bars with thinner diameters leaded to less residual displacement compared to less number of bars with thicker diameters.