Study On RC Beams Strengthened With CFRP Plate Based On The Finite Element Analysis

The safety and durability of the wharfs are mostly influenced by the concrete cracking and rebar corrosion in the reinforced concrete structures which are caused by the wave, seawater erosion and impact of ship. Strengthening the damaged components of the wharfs is important and economic. In recent years, researchers began to research the CFRP (carbon fiber reinforced polymer) material used into the wharf structure strengthening field, and focused on the mechanical properties of structures after strengthened.Based on reinforced concrete beams, which is widely used in harbor engineering as the research object, the accounting treatment of RC (reinforced concrete) beams strengthened with CFRP plates in the FEA (finite element analysis) were studied in the thesis. Research methods and achievements are as follows:Firstly, comparing with a set of reliable experimental results, this thesis gained an effective finite element analysis scheme feasible to study the flexural behavior of RC beams strengthened with both pre-stressed and un pre-stressed CFRP plates based on software ANSYS. Maximum error is 10.9% analyzed by contracting the results of finite element analysis with those eight results of experiments.Secondly, a study of the loss of pre-stress was done by numerical simulation and calculated for the concrete beams strengthening with pre-stressed CFRP plates. After an parametric controlled influence analysis, following conclusions can be drawn:the thickness of the CFRP plates is the biggest influence for the simulation results for the effective pre-stress by decreasing the temperature in FEA. The calculation method of the pre-stress loss and reasonable pre-stress ranges are both given as while.Thirdly, the flexural behavior of secondary loading RC beams strengthened with pre-stressed CFRP plates was studied with birth and death method in FEA. After an parametric influence analysis, the conclusions are as follows:the flexural capacity and rigidity of the secondary loading RC beams strengthened with pre-stressed CFRP plates is improved a lot; comparing with the first loading, the ultimate flexural capacity of secondary loading one is declined but not the rigidity; strengthening works should be started as early as possible at the same reinforcement conditions.The finite analysis scheme and some concluding remarks are useful for the future researches and the engineering applications in harbor engineering.