Stiffness and damping tuning through using a piezoelectric friction damper and a layered structure

Vibration suppression is essential for enhancing the performance of mechanical systems, as it prevents structural damage and minimizes noise. Various methods, including passive, semi-active, and active approaches, have been developed to achieve this goal. Among these, friction dampers, primarily categorized as passive, are highly efficient in adjusting system damping and influencing energy dissipation. By modulating the normal force in the friction damper based on external force intensity, performance can be further enhanced. This study employs a piezoelectric actuator to regulate the normal force and introduces an analytical method along with finite element modeling to estimate the normal force in the friction damper. A layered structure is introduced as an additional mean to tune damping and stiffness. The performance of the semi-active piezoelectric friction damper is investigated in free and forced vibrations, including flexural and axial cyclic loads. Furthermore, the advantages of employing layered structures are investigated experimentally. Overall, the piezoelectric friction damper demonstrates effective energy dissipation during macroslip events. Nevertheless, in case of microslip, increasing the actuator voltage results in reduced damping and a marginal rise in stiffness.