Abstract
To address low-frequency vibration and noise issues in ship grating structures, this study proposes a novel acoustic optimization design method based on modulating flexural wave bandgap characteristics. By establishing an equivalent periodic spring-mass coupled beam model to predict bandgap properties, its effectiveness is validated through numerical simulations and experimental testing. By selectively enhancing longitudinal stiffness while weakening transverse components, the bandgap characteristics are effectively tuned to target frequency bands. This approach achieves an 8.2 dB noise reduction at the 31.4 Hz natural frequency. The results demonstrate that bandgap-based design provides a numerically and experimentally validated solution for low-noise ship structures.