| Abstract:Our research group shear strengthened beams with prestressed and self-locked CFRP strips, which made the most use of CFRP and lead to the sharp improvement of beam’s shear capacity. Based on the group’s research results, this thesis simulated the shear performance of13beams(8of which have been experimentally studied) under pre-load and shear strengthened with prestressed and self-anchored CFRP strips by ANSYS, studied the effect pre-load level and prestress level have on shear performance and set up the fomular of beam’s shear capacity. Main work and results of the thesis are as followed:1. Models of RC T-section beams under pre-load and shear strengthened with prestressed and sel-anchored CFRP strips were set up. The cracking load, ultimate capacity, failure mode, deflection at mid-span, and strain of CFRP strip of13beams were calculated by ANSYS. The models were confirmed to be reasonable by comapring the simulation results to the test ones.2. The simulation results says:When the beams strengthened with prestressed CFRP fails because of the fracture of strips, the ultimate capacity will increase and then go down with the pre-load level keeps going up. It will hit the peak when the pre-load comes to the critical value that makes the beam crack. And the prestress level has little influence on the ultimate capacity under this failure mode.3. When the pre-load makes the beam crack seriously, then the prestress level will have a significant influnce on both the beam’s failure mode and ultimate capacity. Low prestress level will lead to shear failure with low ultimate capacity. While high prestress level will lead to the fracture of CFRP strip with high ultimate capacity.4. Shear capacity of RC T-section beams strengthened with CFRP strips were analyzed according to theory of truss. Formulas of the shear capacity of CFRP strip and strengthened beam were put forward by fitting the experiment and simulation data. The practicality of the formulas was verified by calculating analytical results, which agreed the test and simulation ones well. |
