Analysis on Load-Deformation Curves of the Concentrically Compressed Concrete Filled Circular CFRP-Steel Tubular Stub Columns

Based on experimental study and stress-strain curve of the concrete confined by circular CFRP-steel tube subjected to axial load, the fiber element approach was used to analyse load-deformation curves of the concentrically compressed concrete filled circular CFRP-steel tubular stub columns, and it shows that the results predicted check well with those of the tests and are on the safe side. Influences of confinement factor of the steel tube and the that of the CFRP tube on curves were analysed. The typical load-deformation curves were proposed and it could be defined as following four stages, e.g., elasticity stage, nonlinear stage, strengthening stage and softening stage. The method presented here is suitable for load-deformation curves analysis of the concentrically compressed concrete filled steel tubular (CFST) stub columns with circular cross-section also.