Nonlinear energy sink and targeted energy transfer in smart structures

Nonlinear energy sinks (NESs) are strongly nonlinear mechanical oscillators that are weakly coupled to a mechanical primary system. Through targeted energy transfer (TET), vibration energy is irreversibly transferred from the primary system to the NES, making the NES an attractive passive vibration control device. Furthermore, because of the NES’ strong nonlinearity, the NES has a variable natural frequency, unlike linear vibration control devices. This enables a self-tuning property where the NES adapts to the primary system’s vibration frequency, making the NES a broadband vibration absorber. This self-tuning extends to multi-frequency vibrations through resonance capture cascade (RCC), where the NES tunes itself to the different frequencies in sequential order. Recently, some works have discussed the piezoelectric NES, a nonlinear electrical circuit that interfaces with a mechanical system through a piezoelectric transducer. This paper will show for the first time that by using an electromagnetic transducer instead of a piezoelectrical transducer, an electromagnetic NES is obtained. Furthermore, this work will show that dynamics of mechanical, piezoelectric and electromagnetic NESs can be generalized under a universal NES in a slow flow expression and that resonance capture cascade occurs for all the NES types. The performance of the NES configurations are compared and their physical components are discussed.Nonlinear energy sinks (NESs) are strongly nonlinear mechanical oscillators that are weakly coupled to a mechanical primary system. Through targeted energy transfer (TET), vibration energy is irreversibly transferred from the primary system to the NES, making the NES an attractive passive vibration control device. Furthermore, because of the NES’ strong nonlinearity, the NES has a variable natural frequency, unlike linear vibration control devices. This enables a self-tuning property where the NES adapts to the primary system’s vibration frequency, making the NES a broadband vibration absorber. This self-tuning extends to multi-frequency vibrations through resonance capture cascade (RCC), where the NES tunes itself to the different frequencies in sequential order. Recently, some works have discussed the piezoelectric NES, a nonlinear electrical circuit that interfaces with a mechanical system through a piezoelectric transducer. This paper will show for the first time that by using an electromagnetic transducer instead of a piezoelectrical transducer, an electromagnetic NES is obtained. Furthermore, this work will show that dynamics of mechanical, piezoelectric and electromagnetic NESs can be generalized under a universal NES in a slow flow expression and that resonance capture cascade occurs for all the NES types. The performance of the NES configurations are compared and their physical components are discussed.C