In the present research, concrete frames reinforced with concentric steel bracings were investigated and gusset plates for the bracing systems were modeled with different thicknesses and geometries. These models were constructed in ABAQUS Software, and nonlinear static analysis was used considering nonlinear effects of the materials and geometry. Therefore, the frames were subjected to lateral loads with the loading applied in the form of unilateral displacement. Using the results of the performed analyses, the behavior of the connection sheets was determined and compared with the experimental data to verify the analysis performed by ABAQUS Software. Afterwards, a comparison was made between the sample connection sheets of higher importance in terms of ductility and strength. The results indicated that by introducing the steel bracing systems into the concrete moment frames, load bearing capacity and stiffness of the structures were enhanced by up to about 12 and 3 times, respectively. Furthermore, the strength of the frames containing pentagon gusset plates was higher than those with rectangular and triangular gusset plates about 21% and 24%, respectively. Moreover, the ductility of the reinforced frames with pentagon gusset plates was higher than those of the frames with rectangular and triangular plates about 1.65 and 2.06 respectively. Consequently, pentagon gusset plates are the best option in concentric steel bracings for retrofitting concrete frames.