Experimental and Simulation Study on Vibration Transmission Characteristics and Vibration Isolation Effect of a New Floating Raft Vibration Isolation System

To enhance the floating raft vibration isolation system's effect, a new two-stiffness floating raft vibration isolation experimental was constructed. First, the system's mathematical model was established. The vibration transfer function was deduced via substructure derivative synthesis and four-end parameter matrix methods, and the structural parameter impacts on it were analyzed. Then, a modal test was conducted, and a finite element model was built. Comparing finite element analysis with test results verified the model's validity, followed by a study of the support structure's vibration characteristics. Finally, by measuring acceleration responses at the isolator's upper and lower ends and using the difference as an evaluation index, the isolator's vibration isolation effect on land and underwater was investigated, along with its impact on the device's underwater acoustic radiation. The results demonstrate that the two-stiffness vibration isolator can reduce vibration transmission within a specific frequency range both on land and underwater, guiding practical engineering vibration isolation research.