This paper aims to study the coupling interaction between a truss box floating raft and submarine hull, and proposes a design approach for enhancing the vibration isolation effect of the truss box floating raft-hull coupling system.

First, modal analyses of the aforementioned coupling system and individual floating raft and hull structures are carried out respectively, and comparisons are made of the modal shapes between the floating raft of the coupling system and individual floating raft structure, as well as between the hull structure of the coupling system and individual hull structure. The effects of the thickness of the floating raft panel and isolator stiffness on the isolation of the coupling system in the full-frequency range are then investigated.

The floating raft of the coupling system shows little difference in natural frequency or modal shape compared with the individual floating raft, and the vibration isolation effects are also the same. In addition, the increase in the thickness of the panel and the weakening of the stiffness of the lower vibration isolator will improve the vibration isolation capability of the coupling system.

The results of this study indicate that the mutual influence between the floating raft and hull is small, and can be considered a weak coupling relationship.