SOUND SCATTERING FROM A SUBMERGED MULTILAYERED CYLINDRICAL SHELL WITH FUNCTIONALLY GRADIENT MATERIAL PROPERTIES

An exact treatment based on the inherent background coefficients that describe the background amplitudes in the scattered field is employed to investigate the scattering of timeharmonic plane acoustic waves by an arbitrarily thick hollow isotropic functionally graded cylinder submerged in and filled with non-viscous compressible fluids. The mechanical properties of the graded shell are assumed to vary smoothly and continuously with the change of volume concentrations of the constituting materials across the thickness of the shell according to a power law distribution. The original inhomogeneous shell is approximated by a laminate model, for which the solution is expected to gradually approach the exact one as the number of layers increases. The transfer matrix (T-matrix) solution technique, which involves a system global transfer matrix formed as the product of the individual transfer matrices by applying continuity of the displacement and stress components at the interfaces of neighboring layers, is employed to solve for the modal scattering coefficients. Limiting cases are considered and good agreements with the solutions available in the literature are obtained.

Keywords:

Resonance scattering , inherent background , FGM cylindrical shell