Trends in modeling of structural-acoustics systems with structural complexity in low- and medium-frequency ranges

Abstract

This paper gives a comprehensive survey of a theoretical approach for predicting the frequency response functions of general complex structural acoustics systems (CSAS) in the low- and medium-frequency ranges. For such a CSAS, the complex structure is made of a master structure coupled with internal substructures presenting structural complexity and corresponding to a large number of secondary subsystems, such as equipment units or internal secondary structures, attached to the master structure. The master structure is a general 3-D dissipative structure with an arbitrary bounded geometry and is made of an anisotropic, inhomogeneous, viscoelastic medium. This complex structure is coupled with an external acoustic fluid via the master structure. The approach is based on the use of fuzzy structure theory, introduced by the author in 1985, including recent developments concerning identification of the fuzzy substructure model parameters. This theory allows the effects of the internal structural complexity on the master structure to be modeled. In addition, the construction of an intrinsic reduced model of the frequency response functions of this CSAS adapted to the medium-frequency range (recently proposed by the author) is presented, which allows simplifications in the calculation of the responses to any deterministic or random excitations.