Sound radiation of orthogonally stiffened laminated composite plates under airborne and structure borne excitations

An analytical periodic model is developed to predict the radiation of sound from orthogonally stiffened laminated composite plates under airborne and structure borne excitations. Whilst a layerwise shear deformable theory is used to describe the vibration of the base plate, both the force and moment coupling between the stiffeners and the base plate are considered on basis of flexural-torsion coupling equations. The periodic governing equations are solved using Fourier transformation method. The validity and feasibility of the model is verified by comparing theoretical predictions with existing numerical and experimental results. Numerical discussions with the model demonstrate the significant influence of both flexural-extension and flexural-torsion coupling upon acoustic radiation from un-stiffened composite plate, which depends on material properties, geometrical parameters and frequency.