A Hybrid Vibration Isolation Base Design Based on Symmetrically Distributed Acoustic Black Holes and Locally Resonant Metamaterials

Marine vertical centrifugal pump vibration severely impacts equipment reliability and ship structural integrity, with low-frequency vibration being a key challenge for traditional passive isolation systems. To address this, this study aims to optimize the pump base’s vibration isolation performance by integrating symmetrically distributed acoustic black holes (ABHs) and locally resonant metamaterials. A combined numerical and experimental approach was adopted: an H-shaped ABH-coupling plate dynamic model was established and validated, followed by parametric evaluation of base structures, ABH parameters (length, lABH), damping layer configurations, and metamaterial arrays. Experimental tests were conducted using simulated pump excitation on the optimal prototype. The results show the optimal configuration—symmetrical ABH (lABH= 100 mm) with a full damping layer and 3 × 3 metamaterial array—achieves 11.97 dB low-frequency and 22.01 dB high-frequency vibration suppression, forming a 24.8–27.6 Hz bandgap and 7.43 dB isolation at characteristic frequencies, with an overall 13% performance improvement. This work verifies the feasibility of the symmetrical ABH–metamaterial hybrid system, providing a novel technical solution for high-performance vibration-noise reduction in marine power equipment.