We analyze the dynamics induced by a 2:1 internal resonance between the third (second symmetric) and the fifth (third symmetric) mode of a MEMS microbeam. An extensive experimental investigation is conducted, where forward and backward sweeps are systematically acquired up to elevated excitations. As ramping the voltage, a change along the forward sweep of the resonant branch is noted. This is analyzed via the combined use of different analytical and numerical tools, which show a phase shift between the modes involved in the 2:1 internal resonance. Constantly referring to the experimental data, simulations examine the underlying features of the system's behavior. The dynamics observed in the experimental frequency sweeps are part of a more complex scenario, where different attractors appear and coexist. The experimental behavior bifurcation chart is reported and compared with simulations, which offers a comprehensive view of the 2:1 internal resonance activation. The concurrence of numerical results and experimental data confirms on the effective actuality of these complex features in safe conditions, along wide ranges of the parameters space.
Bibliographical noteKAUST Repository Item: Exported on 2021-02-09
Acknowledgements: The work has been developed during the visit of Laura Ruzziconi to King Abdullah University of Science and Technology (KAUST), Saudi Arabia; the kind hospitality is gratefully acknowledged. Nizar Jaber acknowledges support of King Fahd University of Petroleum and Minerals. This work is supported through KAUST Funds.