New approximations of external acoustic-structural interactions

At LMSSC, Cnam, Paris, June 29th 2006
K.C. Park
Professor, Department of Aerospace Engineering Sciences and Center for Aerospace Structures,
University of Colorado, Boulder, USA

In collaboration with Y.S. Park, Professor, Mechanical Engineering Department, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
New approximate models for external acoustics interacting with flexible structures are developed. The basic local form of the present models is obtained by a combination of the Laplace-transformed retarded and advanced potentials. It is shown that the maximum attainable time-derivative of convergent approximate models is two, hence any attempt to include higher orders will lead to non-convergent models. It is shown that the present approximation is specialized to the so-called DAA1 when the retarded and advanced participation is equal. The basic model is subsequently modified from the consistency considerations of the resulting frequency response functions. The resulting model is expressed in terms of a free parameter that represents the weight of the retarded vs. advanced potential characteristics, and consistent in terms of capturing the correct impulse response. Hence, the present approximate model is well suited for acoustic-field determinations and inverse acoustic identification applications.

Laboratoire de Mécanique des Structures et des Systèmes Couplés - LMSSC