Het gebruik van de eindige elementen methode in akoestische en gekoppelde mechanisch/akoestische systemen

Thie paper describes the development and application of numerical tools for the dynamic analysis of acouetical and structural-acoustical systems. Use is made of an analogon between the differential equations of structural dynamics and acoustics, which enables the use of readily developed F.E.M.-codes (in this etudy NASTRAN). The models on which the dynamic analyses have been performed are an unstiffened circular cylindrical shell and its enclosed volume of air. The types of analyses which have been implemented are: an uncoupled acoustical modal and modal respons analysis, a sound intensity computation on the interface surface of the two models and a coupled structural- acoustical modal analysis. It will be shown that it is strictly necesaary to perform the coupled analysis for this highly idealized fuselage model