Structural Design and Parameter Optimization Analysis of a Novel Three-Dimensional Vibration Isolation Device
Abstract
To resolve the trade-off between stability and vibration isolation performance in linear systems, vertical and horizontal quasi-zero stiffness (QZS) vibration isolators are designed using coil springs and a slider-guide mechanism. A new type of three-dimensional quasi-zero stiffness isolation structure is developed, consisting of one vertical isolation module combined with two horizontal isolation modules arranged orthogonally through connecting components. Analytical results confirm that this system exhibits quasi-zero stiffness characteristics along all three principal axes when maintained in static balance. The effects of different design parameters on the mechanical properties are analyzed, and the parameters of the three-dimensional QZS system are optimized to expand the QZS range and improve low-frequency isolation performance. The dynamics of the system under optimized parameters are studied, and the transmissibility of the three-dimensional QZS system is compared with traditional QZS and equivalent linear systems to evaluate the vibration isolation performance of the new device. Finally, shaking table tests are conducted on the three-dimensional QZS isolator to assess the effect of excitation amplitude on the system. The experimental transmissibility is compared with theoretical predictions, validating the dynamic behavior of the device and confirming its superior low-frequency vibration isolation capabilities.