Structural intensity of cylindrical shell structure under dynamic loading

The vibro-acoustic interior noise of cylindrical shell is normally controlled by the shell surface power flow. The interior noise can be attenuated by redirecting the power flow of the surface. Structural intensity (SI) is the power flow per unit cross-sectional area in elastic media and it is analogous to acoustic intensity in a fluid medium due to structural vibration. Structural intensity occurs as a result of vibration and dynamic loading. In this study, the theoretical expression of structural intensity in cylindrical shell is derived according to the Flugee's thin shell theory and energy balance concept of the structure. From the structural intensity vector and novel streamlines presentation, the energy flow path, the energy flow sources and sinks can be identified. As an example, the structural intensity of circular cylindrical shell under dynamic ring loading is given and the structural intensity vector and streamline are obtained which can be used to identify the vibro-acoustic interior noise source, sink and predominated panels of fuselage structure.