Ductility Demand Survey on Concrete Column Strengthened with CFRP Laminates

This research aims to ductility demand survey on concrete column strengthened with CFRP laminates. Therefore, firstly the main definitions and the review of the previous researches have been described. The behavior of concrete, FRP and reinforcements have been implemented in software computer program. Then, the analytical results has verified after considering and comparing with experimental outcomes. After calibration the software results with presented results by OZCAN et al, the effect of length and thickness wrapping on displacement ductility and rotational capacity of column has been considered. In this way, these columns without FRP, one and two layers FRP wrapping with different lengths have been modeled by ABAQUS as finite elements software. For each column the amount of strain in different location in CFRP material, have been created. The base shear-displacement curve at the end of column and the displacement ductility of columns has been examined. Moreover, the amount of curvature in different location across the length of column and also moment at the end of column has obtained. The obtained results have been compared with some analytical equations. Then the length of plastic hinge and the created rotation at the end of column have been calculated and the effect of length and thickness of CFRP wrapping have also been examined on rotational capacity of the column.
Furthermore, in order to consider the effect of length and thickness of wrapping on seismic performance of columns, based on ATC40 method for estimate of the performance point, spectrum capacity of columns and spectrum seismic demand have been calculated. The performance point of columns have obtained by changing of the spectrum seismic demand curve and capacity to spectrum ADRS coordinates, using collision of these two curves. In this study also the acceptance criteria for nonlinear procedures-reinforced concrete columns wrapping with CFRP for different length and thickness of wrapping, based on analytical results of the amount of dissipated energy in each column has been evaluated, In addition, the maximum plastic rotation angle of the columns has been calculated.