Finite element modeling and design recommendations for low-yield-point steel shear panel dampers

Metal shear dampers are widely used in dissipating earthquake input energy in seismic structures. In this regard, this paper evaluated the hysteresis performance of the low-yield-point 225 steel shear panel dampers (LYP225 SPD) through extensive finite element (FE) analyses. A constitutive model with combined hardening and a memory surface was used in the FE model to describe the cyclic elastoplastic behavior of the steel. The numerical model was verified and validated by comparing the numerical results with the experimental results. Parametric studies were subsequently performed to investigate the effects of design parameters of each component (i.e., the infill plate, the square steel tube stiffeners, and the flange plates acting as the boundary elements). An analytical model was developed to predict the plastic buckling stress of the core plate under monotonic shearing based on the theory of plastic instability and the numerical results. The use of the square steel tube stiffener effectively inhibited the out-of-plane buckling of the core plate and thus improved the hysteresis performance of the shear panel damper. Design recommendations were provided for the stiffness ratio (the ratio of the sectional flexural stiffness of stiffener to the out-of-plane bending stiffness of the core plate) and layout of the stiffener based on the numerical results. Compared with the conventional intact plates, the flange plates with the dog-bone and radius type reduced sections contributed to reduce damage to the roots of the plates and the improvement of the SPD displacement ductility. Increasing the thickness of the flange plate was another effective measure to prevent premature rupture at the flange roots. Design recommendations were provided for each component of the SPD. This study ended with a proposal of the design procedure for the LYP225 steel shear panel damper.