Multi-Stage Vibration Control Mechanism and Experimental Effectiveness of Viscous Damper with Overload Protector.

This research presents an innovative hybrid seismic isolation system that integrates a viscous damper with overload protection (VD-OP) to improve seismic performance and overcome the limitations of traditional isolation methods. The VD-OP incorporates a displacement-dependent nonlinear damping mechanism and a force-limiting feature, effectively controlling excessive damping forces during high-velocity movements caused by varying seismic intensities. A mechanical model, calibrated using experimental data, is developed to replicate the nonlinear damping and overload protection characteristics of the VD-OP. Numerical simulations are validated through experimental testing, providing a solid foundation for optimizing parameters and evaluating performance. The findings show that the force-limiting function plays a critical role in reducing excessive forces on the isolation layer, improving isolation efficiency, and controlling acceleration responses in the superstructure. Parametric studies and case analyses across different seismic scenarios confirm the system's strong energy dissipation capabilities and adaptability, ensuring effective isolation during frequent earthquakes, controlled deformation under design-level events, and structural protection during severe earthquakes. The performance-based design approach proposed here offers practical guidance for the implementation of the VD-OP system, presenting a reliable solution to enhance the seismic resilience of engineering structures.