Steel and Composite Structures

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A numerical study on the plastic rotation capacity of CFRP-confined rectangular RC columns

  • Received : 2019.12.05
  • Accepted : 2021.08.05
  • Published : 2021.09.25
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Abstract

To perform a nonlinear analysis of building frames in their seismic performance evaluation program, appropriate force-deformation curves of the structural members in linear and nonlinear phases which represent their actual behavior are required. Although these curves have been provided for common existing RC elements prior to retrofitting in available instructions, the codes are silent about appropriate practical models for strengthened elements. In this regard, a comprehensive numerical study is conducted in the Finite Element (FE) software VecTor2 to investigate the effects of various influential parameters on the moment-rotation behavior of CFRP-confined rectangular RC columns. The investigated parameters are cross-sectional dimensions, longitudinal and transverse reinforcement ratios, the level of column axial load, concrete compressive strength, and the effective confinement provided by external CFRP wraps. Then, through the idealization of the obtained moment-rotation curves, the influence of the aforementioned parameters on the plastic rotation capacity of the columns as one of the main required parameters to define the nonlinear behavior of the retrofitted columns is investigated. Accordingly, column axial load intensity, shear force, effective confinement, and column depth are found to be the major effective parameters on the plastic rotation capacity of the columns. Finally, a practical method consistent with ASCE 41-13 is presented to estimate the plastic rotation capacity of CFRP-confined columns.

Keywords

References

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