Geometrically linear and nonlinear vibrations of a thin laminated composite plate in contact with fluid

The geometrically linear and nonlinear vibrations (also referred to as low-amplitude and large-amplitude vibrations respectively) of a square thin laminated orthotropic (cross-ply) carbon/epoxy composite plate in contact with air from one side and water from the other were investigated. The plate was bolted to a wall of a steel container. First an experimental modal analysis with the empty container was realised in order to investigate the 'dry' natural frequencies and the 'dry' mode shapes of the plate, then some experimental modal analyses at different water levels were carried out in order to assess the effect of the water on the natural frequencies and the mode shapes of the plate and finally the nonlinear experimental vibration analysis of the plate with and without water contact at different levels was performed.