The Experimental And Numerical Simulation Of CFRP Confined Concrete Square Columns

The Carbon Fiber Reinforced Plastic (CFRP) confined concrete structure has developed rapidly since the later 1990s when its application and research begun, and a great deal of valuable results have been obtained. However, the reinforce mechanism was not resolved well and many worthful research topics remain existing.Based on the reviewing of domestic and overseas reinforced methods, the current problems of reinforced methods were pointed out and the advantages of CFRP were summarized. Based on the test data, the reinforced effect of CFRP confined concrete square columns were analyzed. The reinforced mechanism of CFRP confined concrete columns and other problems have been extensively investigated from the theoretics and numerical analysis of two aspects with different reinforced quantities. The main studies and conclusions are as follows:(1) The test of CFRP confined concrete columns was carried out. The compression test analysis of the fifteen pieces of specimens of CFRP confined plain concrete columns and three plain concrete columns without CFRP indicated that the strength and toughness of concrete have been prominently enhanced, the plastic distortion capability of concrete can be made full use of and has the positive attributes of improving the ductibility of structure due to the CFRP. Meanwhile, the strength of concrete was not increase with the reinforced quantities in geometric series, which means better reinforced rate exists.(2) From the linear regression and non-linear regression analyzing, the simple theoretical formula of peak stress, strain , ultimate stress, strain were put forward. Based on theformula, the different constitutive models of the CFRP confined concrete columns which alternatively have the softening sections and non-softening sections were also put forward, and the models fit well with the test result.(3) Based on the finite element software ANSYS, the CFRP-confined concrete square columns were numerically simulated. The force behaviors of CFRP-confined concrete columns and the reinforcing effect of the concrete square columns with defect were calculated and analyzed, some useful results were obtained. The shear stress and normal stress on the interface between concrete and CFRP were also investigated under different conditions. The results indicated that without considering the interface bond-slip, the interfacial normal stress and shear stress are less than the result considering the interface bond-slip.(4) The artificial neural network model to predicate the reinforced rate of CFRP concrete columns was established. Based on the theoretical analysis, the input variables of ANN model were determined. From changing the nodes numbers of hidden layer, the reasonable ANN model was finally obtained. The better confined rate can be successfully predicted by training mature network and the predicted results fit well with the test results.