Forced vibrations of two plates in fluid and limit eigenmodes

Abstract

Dynamics of two elastic plates, not connected to-gether, is investigated. These plates are in contact with singly connected rectangular domain of ideal incompressi-ble fluid, so coupling of the plates is possible only through the fluid. Interaction between plate modes vibrations and their dependence on the relative position of the plates is investigated. The case of multiple in vacuo eigenfrequen-cies is examined and limit eigenmodes of the system , when density of the fluid vanishes, are presented. The limit eigenmodes as base functions for approximation of forced harmonic vibrations are suggested and benefits of this choice are pointed out.