Abstract
The main objectives of this study are a better understanding of the vibro-acoustic behaviour of an airplane fuselage type structure including stiffeners and a better comprehension of the measuring techniques and the modelization approaches for this type of problem. In order to meet the above objectives, three different models were developed. The first one is an experimental model where the measured accelerations and acoustic pressures are used as a reference for the validation of predicted results. The second model is based on a semi-analytical approach. This model is derived from variational and integral approaches and solved, approximately using a Rayleigh-Ritz method. Finally, the last model is based on the finite element method. Several iterations have been necessary before reaching an excellent agreement between all three approaches, especially regarding acoustic responses. From the initial correlation between the measured and predicted results, two major problems were identified. The first one is related to convergence problem associated with the semi-analytical model when stiffeners are incorporated in the model. The second problem is associated with the proper definition of the fluid-structure intermodal coupling in the numerical and analytical approaches. This paper will present the various approaches and models. Furthermore, the investigation on the previous problems will be discussed in detail. In conclusion, new modelization limitations were identified and new modelization criteria for the intermodal coupling were developed from the present study. These results will be used for an in-depth study on the vibro-acoustic behaviour of 1/3 scale model of airplane fuselage.
