Effects of the characteristics of a force-driven bulkhead on the structural acoustics of an elastic cylinder

To study the structural acoustics of propeller-excited marine vessels, the hull and bulkhead, against which the thrust
bearing is mounted, are often modelled as a circular cylinder and a cross-section plate. This paper concerns the effects of
the characteristics of the cross-section plate on the vibration and radiated sound from the cylinder. The critical aspect is the coupling between the plate and cylinder, as this affects the input power of the excitation force at the plate and energy transfer from the plate to the cylinder and eventually to the radiated sound. The study compares the input mobility, averaged vibration response of the cylinder, and the radiated sound power with respect to the driving force for full-plate and half-plate configurations. Conditions associated with large sound power radiation from the cylinder are assessed through detailed measurement of the distributed sound intensity and vibration on the surface of the cylinder. The results demonstrate the drastic differences in the radiated sound power when different cross-section plates are used, and indicate the importance of coupling between the hull and bulkhead structure for controlling the radiated sound power from the propeller-driven hull–bulkhead structure.