Location-Dependent Performance Analysis and Dual-Functional Optimization of QZS Vibration Isolation Systems Integrated with Energy Harvesters

This study examines the co-optimization of energy harvesting and vibration suppression in quasi-zero stiffness (QZS) isolation systems. A multi-degree-of-freedom model is developed to analyze dual-functional optimization of vibration suppression and energy harvesting, incorporating harvester placement configurations. The Harmonic Balance Method derives frequency-amplitude responses under external excitation, validated through Runge-Kutta numerical simulations. Parametric studies assess stiffness/damping ratios and mass effects on system dynamics, emphasizing 1:3 internal resonance mechanisms. Results reveal that upper-positioned harvesters enhance energy capture while preserving isolation performance. Internal resonance excitation broadens operational bandwidth by amplifying nonlinear coupling effects between subsystems. The work establishes a framework for dual-functional QZS system optimization, targeting ultra-low-frequency vibration isolation coupled with energy harvesting capabilities, while providing theoretical insights for integrated mechanical-electrical design strategies.