Theoretical Analysis And Numerical Simulation On Flexural Behavior Of Bridge Strengthened With Prestressed CFRP

In the last decade, most bridges gradually can not meet with modern traffic requirements, when the increasing rank of traffic loadings and traffic volume along with the extension of bridges' service life are taken into consideration. Therefore, the technology, through maintaining, strengthening and reinforcing the bridge, to extend the service life and improve the performance of bridge has aroused worldwide attention. This is a research subject of great theoretical and practical significance.In the dissertation, the characteristics of Carbon fiber reinforced polymer(CFRP) are highlighted after the introduction of basis principles and methods for reinforcing and maintaining bridge. Carbon fiber reinforced polymer, as a new material in strengthening bridge, has been paid more and more attention. It has a bright future due to its outstanding performances such as high strength, low weight, corrosion resistance, together with the handy operations comparing to traditional strengthening methods. Strengthening reinforced concrete beams with prestressed CFRP sheets, the characteristics of high strength in CFRP exert effectually, restrain the expansion of crack and distortion, improve the performance of the beams greatly.Numerical simulation and theoretical analysis are done for the beams strengthening with prestressed CFRP sheets in this dissertation based on the present experimental results. Firstly, based on the assumption of plane section, non-bonding slip and non-peeled destroy, calculation formula for flexural capacity of prestressed CFRP strengthening reinforced concrete beams are proposed. Secondly, nonlinear finite element analysis by ANSYS is done for the beams strengthened with prestressed CFRP sheets based on the three assumptions as mentioned and appropriate constitutive relations of concrete, steel and CFRP. Finally, a formula for calculating the relative deflection is derived and the failure process of beams strengthening with prestressed CFRP sheets is analyzed by the curve of loading-deflection. The effect of load history is also taken into account. The method and formula confirmed by those results of numerical simulation and calculation in theory are well consistent with the experimental results, which demonstrate the accuracy of the numerical simulation and calculation herein. Those methods are supplementary of simulating experiment and provide evidence for practical design.