Theoretical and experimental investigations on an X-shaped vibration isolator with active controlled variable stiffness

A novel X-shaped variable stiffness vibration isolator (X-VSVI) is proposed. The Runge-Kutta method, harmonic balance method, and wavelet transform spectra are introduced to evaluate the performance of the X-VSVI under various excitations. The layer number, the installation angle of the X-shaped structure, the stiffness, and the active control parameters are systematically analyzed. In addition, a prototype of the X-VSVI is manufactured, and vibration tests are carried out. The results show that the proposed X-VSVI has a superior adaptability to that of a traditional X-shaped mechanism, and shows excellent vibration isolation performance in response to different amplitudes and forms of excitations. Moreover, the vibration isolation efficiency of the device can be improved by appropriate adjustment of parameters.