Tradeoff between mass sensitivity and performance in quasi-zero stiffness vibration isolators

Quasi-zero stiffness isolators are a promising technology to reduce vibration transmission over a large frequency range while maintaining passive operation and low cost. Many different types of QZS isolators have been demonstrated utilizing a variety of mechanical, pneumatic, and magnetic components. While some of these types have their own unique challenges, other challenges are more general. Two of these challenges are mass sensitivity and hysteresis in the load-deflection curve caused by snap-through buckling, friction, or structural damping. This work investigates the impact of force-deflection hysteresis on isolation performance through experimental techniques. Results show that increasing hysteresis reduces the mass sensitivity but worsens the isolation performance at low frequencies. A tradeoff must be made between these two aspects but can be overcome by shifting the QZS region to difference forces. A simple method to achieve this adaptability exists for certain types of QZS structures, therefore enabling a variety of practical applications within a certain design window.