Ultra-thin films effects on vibro-acoustic behaviour of laminated plate including a viscoelastic core

In this paper, the vibro-acoustic behaviour of a laminated glass plate composed of two elastic skins, a viscoelastic core and two ultra-thin adhesive films; is investigated. Here, the coupled dynamic model is derived by mixing the classical plate's theories (Mindlin and Kirchhoff models) and the specific behaviour law for the ultra-thin films, previously introduced in our published works in Applied Acoustics Journal [1], with an integral equation formulation for the acoustic radiation of the studied structure. The discretized coupled dynamic equation associated to the energy functional is solved in order to determine the vibratory and acoustic efficiency of the designed laminate. For this purpose, a numerical validation of the finite element model is achieved by using the calculated results corresponding to a standard sandwich plate. In order to predict the vibro-acoustic responses, a modal recombination method is developed by taking into account the external fluid radiation. Hence, the effects of many parameters on some vibro-acoustic indicators (deflection, strain energy, transmission loss) such as core thickness, geometrical property, modal damping and boundary condition are presented and discussed. Especially, the influence of the ultra-thin adhesive films due to the coupling with the viscoelastic core on both dynamic and vibro-acoustic behaviours of the laminate is presented and analyzed.