Optimal Distribution of Viscoelastic Dampers in Steel Moment-Resisting Frames Using a Generalized Frequency-Dependent Damping Model

Abstract

The optimal distribution of viscoelastic dampers in steel moment-resisting frames has become a key strategy to improve seismic performance while maintaining structural efficiency. This study presents a comprehensive framework for optimizing the placement and quantity of viscoelastic dampers based on a generalized frequency-dependent damping model. The model accounts for the viscoelastic material’s dependence on excitation frequency, enabling a more accurate prediction of damping behavior in real seismic conditions. The research methodology combines nonlinear dynamic time-history analyses of multi-story steel moment frames with a multi-objective optimization approach targeting maximum energy dissipation and minimum inter-story drift. Genetic algorithms and parametric modeling techniques are implemented to determine the optimal damper configuration across different frame heights and load conditions. The study evaluates the effects of damper placement, stiffness ratios, and frequency-dependent parameters on the global and local seismic responses of the frames. A comparative analysis between the generalized damping model and classical Maxwell or Kelvin–Voigt representations demonstrates the superiority of the frequency-dependent approach in capturing realistic hysteretic behavior. Experimental data from recent large-scale shaking table tests are used to calibrate the analytical model. The results reveal that a non-uniform distribution of viscoelastic dampers—concentrated near the upper third of the frame—yields higher energy absorption and lower inter-story drift under near-fault earthquake excitations. This research contributes to the development of advanced damping models and practical optimization strategies for high-performance steel structures in seismic regions. The outcomes provide engineers with design insights for implementing cost-effective and structurally efficient viscoelastic damping systems. The proposed framework can be integrated into performance-based seismic design codes to enhance resilience and safety of steel moment-resisting frames in future infrastructure