Vibration isolation characteristics of a novel composite flexible vibration-damping foundation

To address the challenge of low-frequency vibration in ships, we introduce a vibration isolation technique and a composite flexible vibration-damping foundation grounded in the principles of impedance equalization and the off-plane attenuation properties of surface waves. We utilize a fluid-structural coupling finite element method and experimental validation to analyze the effect of various properties of the liquid layer of the base. The results indicate that the composite foundation offers superior vibration isolation compared to traditional foundations across a frequency range of 10-500 Hz. Enhancements in the liquid's viscosity and an increased layer thickness are found to significantly bolster the foundation's ability to isolate vibrations. The relationship between liquid density and the vibration isolation performance of the base is not entirely positive. An increase in liquid density does provide some improvement to the vibration isolation performance at higher frequencies. Additionally, the presence of multiple liquid sacs within the foundation has a minimal influence on low-frequency isolation but proves to be increasingly beneficial at higher frequencies. Through this study, we aim to provide fresh perspectives and solutions for the attenuation and management of low-frequency vibrations in ships.