Vibration response of a two-dimensional heavy fluid loaded plate with ABH stiffeners

Abstract

Acoustic black holes (ABHs) are a promising passive-control approach to mitigate plate vibrations in various engineering applications. By creating a gradient in the flexural waves, an acoustic black hole can trap and dissipate these waves, thereby reducing the amplitude of the vibrations in the plate. The ABH is based on gradually decreasing elastic plate thickness (to trap) and utilizing a damping layer to dissipate the wave energy. This technique has been applied to various structures, and hereby it is proposed to apply it to the stiffeners, commonly used to reinforce structures to increase their stiffness and reduce their susceptibility to vibrations. The studied structure consists of a heavy fluid-loaded infinite plate periodically stiffened and excited by a line force, i.e., a two-dimensional model. In the developed model, the stiffeners are characterized by their flexural and torsional impedances and can be estimated by a finite element analysis. These impedances are then coupled with the analytical formulation of the fluid-loaded plate problem expressed in the wavenumber domain to obtain the spectral displacement. The effectiveness of the ABH-shaped stiffeners in mitigating the plate’s vibration is demonstrated by comparing against results from rectangular stiffeners.