A hybrid numerical and experimental approach for structural intensity analysis of stiffened lightweight structures

Aircrafts are lightweight structures and as such they are prone to vibrations, which make them susceptible to structure-borne noise. Especially, engine induced vibration and their transmission as structure-borne noise towards the aircraft cabin are of interest. In order to implement optimal noise treatments for cabin comfort improvement it is essential to identify the transfer path from the engines through the wings and fuselage into the cabin. On the numerical side Structural Intensity Analysis is a established method to identify the energy transfer paths. With the help of Finite Element models, rather complex structures can be investigated because detailed mathematical models are provided. In this paper a hybrid method is proposed in order to estimate the energy transfer paths of complex structures using experimental response data obtained from a laboratory structure and a full-sized aircraft fuselage. This method combines experimentally determined velocities and numerical methods known from the Finite Element Analysis.