Finite−element approach to acoustic scattering from elastic structures

An approximate method is presented for solving the equations of motion that describe the scattering of an acoustic wave by an elastic structure immersed in an infinite fluid medium. The mathematical model that is developed uses the finite−element method to calculate the vibrational response of the elastic body and to calculate the acoustic pressure field of a finite volume of the fluid medium which closely surrounds the elastic body. Analytical methods are used to obtain the boundary conditions for this mathematical model. Results are presented for the total scattering cross section, axial pressure, and scattering patterns for an acoustic plane wave at normal incidence on an aluminum disk.Subject Classification: 30.30, 30.40.