Advanced Vibration Mitigation with Novel Stiffened Inertial Amplifier Designs

Inertial amplifiers are receiving increasing attention due to their superior potential for vibration attenuation under a wide range of dynamic excitations. This paper proposes and subsequently analyzes new inertial amplifier designs capable of simultaneous amplification of the effective mass and stiffness of a resonant single-degree-of-freedom dynamic system. The inertial amplifier configuration is conceived through constrained link-bar mechanisms with masses and springs attached at selected points. Three new configurations, namely the compound, nested, and levered inertial amplifiers, are introduced. The mass and stiffness amplification factors for all the amplifiers are derived in closed form by analysing the dynamics of the underlying mechanisms. Based on the analytical expressions, parameter choices for superior amplification are obtained analytically. Numerical results demonstrate that it is possible to achieve several orders of magnitude of mass and stiffness amplifications. Using the amplified effective mass and stiffness, the ability to tune the natural frequency of the inertially amplified dynamic system has been established. The inertial amplifiers proposed and designed here will deliver significantly higher effective mass and stiffness than what is used within the mechanisms. This will lead to superior passive vibration control opportunities, exploiting the ability to manipulate the resonance frequency of the underlying oscillatory system.