| الوصف: |
Engineering requirements and system specifications tend to be rather broad in mechanical engineering design. Indeed, users want the broadest possible capabilities of an artifact with the least possible cost. Unfortunately, linear vibration absorbers designed for engineering applications are limited solutions. Most of the passive absorbers available for commercial use, such as tuned mass dampers, work over a very limited bandwidth and require fine tuning procedures and constant maintenance as they may suffer detuning over time. Therefore, innovative solutions are required to overcome these limitations thus enabling a more efficient way of reducing the vibratory response of structures with the least possible addition of mass. Nonlinear energy sinks are devices that take advantage of nonlinear principles to absorb and dissipate energy produced during the vibration of a host system, in an irreversible way. Several different classes of devices have been proposed by scholars, most of them as proof of concept and experimental prototypes. This dissertation focuses on the design, modeling, characterization and experimental verification of a class of nonlinear energy sink, based on a cantilever beam vibrating laterally between two specially shaped surfaces that limit the vibration amplitude, thus providing a variable beam length throughout its deflection, therefore producing a smooth nonlinear restoring force. First, a methodology to evaluate and visualize the energy interactions between the nonlinear energy sink and its host structure is developed. Then, an semi-analytical dynamic model for simulating the device under actual working conditions is proposed, and finally, an experimental verification phase is conducted where the numerical results are verified and correlated. |