Comparison of Dynamic Performance of an All-Metallic Vibration Isolator by Elliptic Method and Frequency Sweeping Method

A horizontally symmetric all-metallic vibration isolator (AM-VI) is proposed to further investigate the dynamic mechanical performance. The novel AM-VI was constructed by combining hat-shaped metal rubber and oblique springs, which were connected in parallel. The springs were arranged symmetrically relative to the support. The elliptic method and the frequency sweeping method were used to compare the dynamic stiffness and the loss factor of the AM-VI. The results demonstrated that the dynamic stiffness and the loss factor calculated by two distinct test methodologies were considerably different, indicating that the inertial force effect of the dynamic testing equipment should be taken into count when adopting the elliptic method. Furthermore, when the vibration isolation performance was evaluated by utilizing mechanical impedance and force transmissibility, the AM-VI achieved excellent vibration isolation performance within a broad frequency range.