Performance-Based Assessment of Nonlinear Pendulum Impact Dampers for Structural Risk and Resilience

Extreme events often provoke critical structural vibrations, compromising building performance and resilience. Particle impact dampers (PIDs) are widely recognized as effective passive vibration control devices; however, their nonlinear dynamics and unpredictable particle motion limit adaptability under uncertain hazard conditions. This study introduces a pendulum-type PID configuration designed to enhance controllability and energy dissipation by tuning particle frequency through suspension. Both the primary structure and particles are modeled as pendulums, and their interactions are analyzed under free and forced vibration scenarios. A comprehensive parametric study reveals that increasing the frequency ratio (F.R), defined as the ratio of particle natural frequency to that of the structure, significantly improves damping efficiency. At F.R = 5.0, with clearance d = 0.1 and restitution coefficient e = 0.2, the system achieves an average damping ratio of approximately 0.28 in free vibrations. Under resonant forced vibration, the proposed damper reduces amplitude ratios to below 0.3 compared to undamped conditions. The results confirm that lower clearance and restitution values consistently yield superior damping performance. The findings demonstrate that the pendulum-type PID offers a customizable, cost-effective solution for mitigating structural vibrations, thereby contributing to risk-informed and resilience-oriented design strategies for building structures exposed to extreme events.