Dual-Functional Energy Harvesting and Low-Frequency Vibration Attenuation: Electromagnetic Resonant Shunt Series Quasi-Zero-Stiffness Isolators  
[PERSON]  
1 College of Naval Architecture and Ocean Engineering, Naval University of Engineering,  
springs [10; 11; 12], prebuckled beams [13; 14], geometrically nonlinear structures [15; 16; 17], magnetic structures [18; 19; 20; 21; 22], bio-inspired structures [23; 24; 25], and composite structures [26; 27; 28]. Nevertheless, it is worth noting that many of the aforementioned NSMs are passive mechanisms, which means their stiffness cannot be adjusted. Passive isolators with unmodifiable stiffness typically lack the capability to effectively handle varying excitation frequencies. Although active control methods have been introduced to enhance the stability and isolation performance of the QZS VIs [29; 30], it is crucial to take into account the potential drawbacks, such as the high costs associated with their implementation. Active or semi-active NSMs, as mentioned in references [31; 32; 33; 34; 35], offer improved adaptability to varying environmental conditions. By using high-precision sensors and actuators, it becomes possible to accurately control the NS characteristic. For magnetic NSM, the NS characteristic is achieved by employing carefully arranged magnets. These arrangements enable the non-contact force to exhibit the desired negative-stiffness behavior. In vibrating systems, a damper is commonly employed as an energy dissipation device to suppress vibrations. Its primary function is to convert vibrational energy into other forms of energy. To utilize vibrational energy, the energy dissipated in the vibration-damping process can be converted into valuable electrical energy. Shunt dampers (SD) have emerged as a highly effective method for suppressing vibration and harvesting energy [36; 37; 38]. The SD demonstrate viscous damping effects, while the presence of an inductor and a resistor introduces electrical resonance, which can act as a vibration absorber. In 1979, [PERSON] [39] was the pioneer in showcasing the application of passive circuit shunting to reduce narrow-band resonant mechanical responses. Subsequently, [PERSON] [40] provided analytical interpretation and experimental evidence to demonstrate that a piezoelectric shunt with an RL circuit can function as a TMD. [PERSON] [41] first proposed the concept of an electromagnetic shunt damper (ESD) equipped with an RC shunt circuit, which offers increased flexibility in adjusting damping force by altering the electrical resistance within the damper circuit. Furthermore, the vibrational energy initially dissipated by the damping element can be effectively transformed into electrical energy through the utilization of electromagnetic equipment. In pursuit of this objective, researchers have proposed the concept of electromagnetic-resonant-shunt-tuned mass dampers (ERS-TMD) [42] as well as electromagnetic-resonant-shunt-tuned mass dampers with inerters (ERS-TMDI) [43; 44; 45]. For further information on low-frequency vibration energy harvesting, a comprehensive review by [PERSON] [46] provides additional insights and reports in this field. Although there are many papers about vibration control or energy harvesting, studies focusing on the integration of both aspects are relatively scarce. The main contribution of this paper is to propose a novel retrofit model that combines dual functionality for energy harvesting and low-frequency vibration attenuation by integrating the ERSD and the TQZS VI. The nonlinear governing equations of the ERS-TQZS VI are approximately analytically solved using the HBM in combination with the PLM. Additionally, a comprehensive parametric study is performed to evaluate the performances of vibration attenuation and energy collection of the ERS-TQZS VI. This paper mainly studies the model structural design and theoretical analysis of the ERS-TQZS VI model.