Abstract: The stress transmission process in the FRP sheet was analyzed numerically during the failure process of the FRP reinforced concrete specimen, characterized as the stress initiation, propagation and final decay of the loading capacities. Based on the examination of the mechanical properties of reinforced concrete structures under different FRP sheet lengths, it was found that the ultimate strain and the toughness, as well as the loading capacity and tensile stress sustained by the FRP sheet, increase with the RFP sheet length, and more cracks are also distributed on the bottom of the beam. For the shorter FRP sheet, the debonding failure is prone to occurring.