The effect of ribs on the sound radiation directivity of rectangular plates

An analytical solution utilizing a double finite sine integral transform method is presented in this study for the sound radiation prediction of a ribbed rectangular plate structure under various combinations of clamped and simply supported boundary conditions. An advantage of the modeling method is that the plate-beam structural coupling and the structure-fluid coupling are automatically defined in the integral transformation without the need to manually select the mode shape function. The model is then utilized to investigate the effect of ribs on the radiated sound power and directivity of the plate structure under resonant and non-resonant conditions, respectively. The result shows that the ribbing effect on the omnidirectional radiated sound field of the rectangular plate is consistent with the change of the radiated sound power. However, the radiated sound pressure may increase at certain directions even if the radiated sound power of the rectangular plate is suppressed by the inclusion of ribs. The effect of periodic ribs on the sound radiation of the rectangular plate is also explored. The insights gained from this study can inspire the noise design for structures such as marine platforms and high-speed rail carriages.