Vibro-acoustic behaviour of shear deformable laminated composite flat panel using BEM and the higher order shear deformation theory

The vibro-acoustic responses of the laminated composite flat panel in an infinite rigid baffle under the influence of central and eccentric harmonic point excitation are investigated numerically. A general mathematical model of the flat panel is developed in the framework of the higher order shear deformation theory to compute the vibrational properties. The system governing equations are obtained using Hamilton's principle and discretised through suitable finite element steps. An in-house computer code is developed based on a coupled finite and boundary element formulation in MATLAB environment and employed to compute the associated acoustic radiations from the vibrating plates. Lab scale experiments (modal analysis) are performed to validate the natural frequencies obtained using the present scheme. The proposed formulation is validated for acoustic responses by comparing the present sound power level with the results available in published literature alongside the results obtained using commercial finite element package (ANSYS). The validation study demonstrated the inevitability of the present formulation in predicting the vibro-acoustic response of the layered composite plate. The geometrical parameters (aspect ratio, thickness ratio), composite material properties, lamination scheme and support conditions are found to have significant influence on the vibro-acoustic behaviour of laminated composite flat panel.