Seismic response reduction using a tuned pendulum pounding mass damper: Experimental verification of superior performance

The recent seismic events have underscored the importance of resilient designs in mitigating losses to life and property. While tuned mass dampers (TMDs) have demonstrated their effectiveness in reducing structural vibrations, they have limitations in safeguarding buildings against non-structural damage caused by earthquakes. Additionally, their efficacy can be overwhelmed in high-magnitude seismic events. This paper introduces a novel device, called the tuned pendulum pounding mass damper (PTMD), that adapts the TMD by introducing a pounding surface near its static equilibrium position. The hypothesis is that this modification will yield superior performance in earthquake mitigation. To test this hypothesis, we conducted a shake table experiment on a PTMD installed in a small-scale building model with a viscoelastic material to model the pounding effects. The study demonstrates that the PTMD's tuning frequency ratio can be analytically determined, although careful selection of the pounding stiffness and restitution coefficient is essential for optimal design. With a mass ratio of 1%, the PTMD significantly reduced the acceleration response. In comparison to the TMD, the PTMD exhibits greater robustness and effectiveness in reducing responses across a broader range of frequencies. Conversely, the TMD may amplify structural responses when detuned. The PTMD's exceptional capabilities position it as a promising candidate for shaping the future of infrastructure and contributing to seismic mitigation policies, thereby enhancing overall disaster resilience.