PARAMETER-ESTIMATION IN A STRUCTURAL ACOUSTIC SYSTEM WITH FULLY NONLINEAR COUPLING CONDITIONS

A methodology for estimating physical parameters in a class of structu ral acoustic systems is presented. The general model under considerati on consists of an interior cavity which is separated from an exterior disturbance by an enclosing elastic structure. Piezoceramic patches ar e bonded to or embedded in the structure; these can be used both as ac tuators and sensors in applications ranging from the control of interi or noise levels to the determination of structural flaws through nonde structive evaluation techniques. The presence and excitation of the pa tches, however, changes the geometry and material properties of the st ructure as well as involves unknown patch parameters, thus necessitati ng the development of parameter estimation techniques which are applic able in this coupled setting. In developing a framework for approximat ion, parameter estimation and implementation, strong consideration is given to the fact that the input operator is unbonded due to the discr ete nature of the patches. Moreover, the model is weakly nonlinear as a result of the coupling mechanism between the structural vibrations a nd the interior acoustic dynamics. Within this context, an illustratin g model is given, well-posedness and approximation results are discuss ed and an applicable parameter estimation methodology is presented. Th e scheme is then illustrated through several numerical examples with s imulations modeling a variety of commonly used structural acoustic tec hniques for system excitation and data collection.