چكيده به لاتين
In the present thesis, using the developed relations for the vibrations of a sandwich spherical shell filled with an electrorheological fluid, and coupling the structural and acoustical equations, the scattering of such systems is investigated. To model the problem and obtain the governing equations, the classical shell theory was used for the elastic layers. Moreover, the viscoelastic Kelvin model was used for the electrorheological fluid, and the linear wave equation was used for the acoustic medium. Then, by expanding the displacement field of the shell and its incident, scattered and transmitted waves in spherical coordinates, a linear system of equations was obtained to describe the scattering of the system. The obtained solution was modeled in Mathematica, so that the effect of related parameters to the electrorheological fluid and scattering could be studied. The obtained equations is an appropriate starting point to further study the related researches in this field, particularly active control of scattering, which is the main purpose of following such researches. Subsequently, a sliding mode active control (SMC) strategy is set up to reduce acoustic scattering of the system.
