The accurate calculation of the deformation capacity of structures is very important to performance-based seismic design
which satisfies the explicit deformation demands. The method to evaluate drift capacity of fiber reinforced polymer (FRP) confined reinforced concrete circular columns under simulated seismic loading is focused. Firstly
the moment-curvature relationship of FRP confined sections of reinforced concrete (RC) circular columns is simulated by numerical analysis. It is found that the calculated ultimate curvature is significantly less than the test result
and the difference is controlled by the axial load ratio of the tested columns. According to the numerical and the test results
an equation is proposed to modify the calculated ultimate curvature. Based on this
the drift capacity can be predicted with the equivalent plastic hinge method. The calculated result agrees well with the test result when FRP amount is low
but it is significantly larger when FRP amount increases. Finally
the main parameters exerting influences on the drift capacity of the FRP-confined RC circular column are analyzed.