Behavior and Design of Dumbbell-Shaped Steel Strip Dampers

Recent developments have explored slit-yielding dampers based on in-plane yielding of steel strips due to their potential for high ductility, stable hysteretic response, and predictability using simple formulas. This paper delves into the investigation of dumbbell-shaped steel strip dampers, analyzing the impact of geometry on factors such as plastic strain accumulation, buckling behavior, and energy dissipation capacity. The study employs a non-linear Finite Element Method (FEM) model, validated through static and cyclic load test specimens. Nonlinear buckling analysis, incorporating considerations of initial imperfections, is then conducted to explore potential limit states under monotonic and cyclic loading conditions. A computational parametric study explores various geometric properties of dumbbell-shaped steel strips. The findings from the parametric study are utilized for regression analysis. A design formula is proposed for practical engineering, defining the critical slenderness of steel strips to avoid reaching a brittle lateral torsional buckling limit state. Its effectiveness is demonstrated through a comparison with nonlinear analysis results under cyclic loading. The proposed design formula can serve as a practical tool for engineers to prevent undesirable limit states, showcasing the significance of geometry in optimizing the performance of structural fuses for seismic energy dissipation.