A Novel Tuned Mass Damper with Negative Stiffness Mechanism for Low-Frequency Vertical Vibration Control

Conventional tuned mass dampers (TMDs) require substantial static displacement when designed for low-frequency vertical vibration control, which poses major challenges in applications where installation space and structural compactness are critical. To address this issue, this study proposes a novel TMD integrated with a negative stiffness mechanism (TMD-NSM). The NSM is realized using a cam-roller-leaf spring assembly, providing effective negative stiffness while maintaining a compact, low-friction configuration. A systematic design methodology is developed, including derivation of the cam surface profile and a step-by-step parameter selection procedure. The governing equation of motion, accounting for viscous damping and friction, is derived to predict the dynamic behavior of the TMD-NSM. Experimental validation using physical models demonstrates that a TMD-NSM tuned to 0.15 Hz limits static displacement to only 1.7 m, which is substantially lower than the over 11 m required by a conventional TMD. Numerical parametric studies further examine the effects of TMD mass, tuning frequency, leaf spring predeflection, and friction between cam and roller on system design and performance, highlighting the TMD-NSM’s robustness and flexibility. The results confirm that the proposed TMD-NSM provides an effective and practical solution for low-frequency vertical vibration control in large-scale civil structures.