On the investigation of the natural mode characteristics of an internal supporting substructure interacting with a submerged main structures in terms of acoustic radiations

Abstract

This paper investigates acoustic radiation characteristics of an internal structure supported in a submerged main structure. An exciting force is applied on the internal structure where vibration is transmitted across the interfacial boundary between these two structures and radiating acoustic power into water through the surface contacting with water. In the previous study (Chen, in 176th ASA meeting, Vol. 144, p. 1680), compliant matrices describing the internal structure and the main submerged structure are proposed, which are both symmetric matrices where the imaginary part of the compliance matrix of the submerged main structure is responsible for acoustic radiation, whereas the matrix for the internal supporting structure is real. These two compliance matrices which are defined on the interfacial boundary fully describing the submerged structural dynamics of this coupled system. It was shown that the parameters, such as thickness and stiffened plate, of the internal structures are very sensitive var...