Theoretical and experimental study on seismic performance of T-section metallic damper

The poor stiffness and strength of traditional U-shaped dampers is an issue that is addressed in the present work by the development of a new form of T-section metallic damper, termed as the TSMD. Theoretical and experimental studies are carried out to evaluate the seismic performances of TSMD. Based on the principle of virtual work and Castigliano's second theorem, theoretical formulas of yield strength and initial stiffness of TSMD are derived and verified. Stiffness, strength and energy dissipation capacity of TSMD are significantly higher than those of the U-shaped damper with the same size of flange. A finite element model which can capture the cyclic responses and fracture failures of TSMD is established. Based on the numerical simulation and parametric study, the effects of geometrical dimensions and material properties on the seismic performances of TSMD are quantified. The mechanical characteristics of the damper are significantly affected by the web width, height, flange width, and thickness of the T-section of TSMD. Shape memory alloy-made TSMD shows stronger strength hardening and fracture resistance capacities than traditional steel-made TSMD and decreases damper residual displacement after cyclic loading. This study aims to provide valuable insights into the behavior and potential applications of the TSMD.