An active high-static-low-dynamic-stiffness vibration isolator with adjustable buckling beams: theory and experiment

High-static-low-dynamic-stiffness (HSLDS) vibration isolators with buckling beams have been widely used to isolate external vibrations. An active adjustable device composed of proportion integration (PI) active controllers and piezoelectric actuators is proposed for improving the negative stiffness stroke of buckling beams. A nonlinear output frequency response function is used to analyze the effect of the vibration reduction. The prototype of the active HSLDS device is built, and the verification experiment is conducted. The results show that compared with the traditional HSLDS vibration isolator, the active HSLDS device can broaden the isolation frequency bandwidth, and effectively reduce the resonant amplitude by adjusting the active control parameters. The maximum vibration reduction rate of the active HSLDS vibration isolator can attain 89.9%, and the resonant frequency can be reduced from 31.08 Hz to 13.28 Hz. Therefore, this paper devotes to providing a new design scheme for enhanced HSLDS vibration isolators.