Experimental and numerical validation of center-rotation type self-centering link beam with SMA bars

This paper innovatively proposed a center-rotation type self-centering steel angle energyconsuming link beam. The influences of the SMA connection types and steel angle materials on the self-centering and energy dissipation capabilities of link beams were studied. The structural self-centering performance, energy dissipation capacity, bearing capacity, ductility, failure mode and stress distribution were analyzed through experiments. The finite element method was used to verify the test and the improved design specimens were proposed. The research results show that the self-centering link beam has a better rotation mode, and the plastic deformation is mainly concentrated on the energy-dissipating steel angles, showing excellent energy-dissipation capability. The full-length arrangement of SMA can improve the self-centering performance of the link beam and has little impact on the energy dissipation capacity. Q235 steel angle can greatly increase the energy dissipation capacity of link beams and affect the self-centering performance. The finite element results are consistent with the tests. The improved design specimens have typical double-flag hysteresis curves, which have better self-centering performance, but the energy dissipation capacity is reduced. The link beams did not undergo plastic deformation after the earthquake, and the structural function can be quickly restored by replacing the steel angles.