Date of Award
2024
Degree Type
Thesis
Degree Name
Master of Science in Mechanical Engineering and Applied Mechanics
Department
Mechanical, Industrial and Systems Engineering
First Advisor
David Chelidze
Abstract
Efficient passive vibration absorption can prevent the failure of systems without requiring sensors or energy sources. Nonlinear energy sinks (NES) have gained popularity as passive vibration absorbers due to their targeted energy transfer (TET) mechanisms that extract and dissipate vibrational energy over broad frequency ranges. In this thesis, a bistable rotary nonlinear energy sink (BRNES) was studied numerically and experimentally in the cases of impulse and harmonic excitation. The original BRNES design involves a pivoting spring, creating a nonlinear restoring force that introduces bistability and favorable oscillatory TET mechanisms. This vibration absorber outperforms the traditional rotary NES and, in some cases, even the bistable NES, while simultaneously acting efficiently at multiple orientations. Moreover, a monostable and bistable configuration of a magnetic rotary nonlinear energy sink (MRNES), which acts as a variation of the original BRNES design, was found to provide additional benefits. When the systems’ parameters are tuned to exploit their linear and nonlinear characteristics, the MRNESs can overcome the shortcomings of many NESs, which are inefficient at low excitation magnitudes, while also outperforming linear tuned mass dampers (TMD) when the system’s parameters are detuned at large excitation magnitudes, for both impulse and harmonic excitation. Thus, as shown by the numerical simulations and experiments discussed in this work, these vibration absorbers can be used to efficiently suppress the vibrations of mechanical systems over broad excitation magnitude and frequency ranges.
Recommended Citation
Treacy, Collin P., "TARGETED ENERGY TRANSFER IN A BISTABLE ROTARY NONLINEAR ENERGY SINK" (2024). Open Access Master's Theses. Paper 2466.
https://digitalcommons.uri.edu/theses/2466