Effect of translation-rotation coupling motion on a 3-Dof horizontal vibration isolation system

Coupling motion inevitably occurs to multi-DOF (Degrees of Freedom) vibration isolators. While complex structures may introduce coupling, additional factors like manufacturing errors and variations in experimental setup also contribute. This paper examines a 3-DOF horizontal vibration isolation system composed of four isolator units, focusing on the translation-rotation motion induced by deviations of the payload center. A mechanical model of the system is developed using the energy method, resulting in a dynamic equation with nonlinear parameters. The impact of these nonlinear parameters on the system's response and bifurcation analysis are explored to reveal key principles governing translational and rotational motion.