Abstract：
According to the characteristic of the force bearing of the reinforced concrete beams in commission, the software was adopted to establish the separate finite element model of the beams, and the strengthened beams and the whole process of loading were simulated, and the effects of first and secondary loading on the deflection of strengthened beams were surveyed. The comparison between the simulation results and the calculation results of four beams showed that the proposed method was a precise numerical tool. The formulas for calculating the short-time deflection of the strengthened beams were established for engineering design. The calculation results and the results of further non-linear finite element analysis showed that the stiffness of the high strength reinforced concrete beams could be improved effectively by using bonded carbon fiber sheet, and the development of crack could be delayed. The numerical calculation values correspond well with the theoretical values. The established separate finite element model could truly reflect the force bearing of the beams. Therefore, the load-deflection relation curves resulted from the numerical calculation truly reflect the deformation rule of the beams. They provided good reference for engineering design.
