Simulation of nonlinear cyclic behavior of a brace member using fiber beam-column element

Concentrically braced frames are one of the most used seismic resistant systems in structures. In such systems, all of nonlinear deformation must be occurred in brace members and other structural elements should be remain elastic. In this paper, fiber element model has been used to simulate nonlinear cyclic response of brace members to reverse seismic excitations. Both geometrical and material nonlinearity have been taken into account. For considering material nonlinearity, a bilinear uni-axial stress-strain behavior with strain hardening has been used. Geometrical nonlinearity has considered using a transportation matrix from basic to global coordinate system. Strength degrading due to ultra-low cycle fatigue has not been considered. To prove accuracy of the model, a comparison between results from numerical analysis and those from available experiments has been made. Results show that the fiber element model can accurately simulate nonlinear cyclic behavior of brace members

Keywords:

Fiber element , nonlinear behavior , cyclic , brace member , beam-column