A compact isolator for multi-directionally coupled vibration

Engineering structures are frequently subjected to multi-directional vibrational excitation, calling for the consideration of multi-directional dynamic coupling and its embodiment in vibration isolation design. This paper introduces a 3D-printed integrated isolator designed to attenuate vibrations in two translational and one rotational directions. The structure comprises rigid rods connected by optimized torsional springs to enable three-directional vibration isolation. Corresponding models alongside the solving procedure are developed, followed by dynamic analyses and experimental validations. The proposed isolator is shown to entail effective low-frequency and multi-directional vibration isolation. Vertical direction performance remains robust and amplitude-insensitive, and negligibly affecting the horizontal and rotational directions; whereas horizontal isolation deteriorates under rotational excitation with amplitude-dependent severity and vice versa. The rotational excitation is the primary source of both nonlinearity and static equilibrium position offset. This study offers invaluable insights for designing multi-directional isolators for aerospace and transportation applications.