Damping device through autoparametric effect

Abstract

This paper presents a new design of nonlinear dynamic absorber (NDA) using the phenomenon of autoparametric interaction between the first symmetric mode and the first anti-symmetric mode of a curved beam to reduce the resonance vibration of a primary structure with a controllable operational frequency range. For a typical autoparametric theory of a curved beam, the lowest excitation force required to initiate an energy transfer from the first symmetric mode (q₁) to the first anti-symmetric mode (q₂) involves tuning the ratio of the resonance frequencies of the first symmetric mode (ω₁) and first anti-symmetric mode (ω₂) to close 2. The resonance frequency of the first anti-symmetric mode (ω₂) can be altered to control the operational frequency range. The autoparametric vibration response can be used to create an energy-dissipative region to achieve a controllable bandwidth. It is also possible to create a non-dissipative frequency region in between two dissipative frequency regions. This is useful for providing damping with a conventional mass damper. Numerical calculations indicate that the resonance vibration of a primary structure can be successfully reduced using this approach.