Variable kinematics multilayered plate elements for vibro-acoustic analysis of shunted piezoelectric structures

Smart composite structures embedding sensors and actuators have been studied over the last decades to improve the performance of aerospace systems in terms of structural vibration control, acoustic radiation suppression and weight reduction. Piezoelectric transducers are among the most studied applications for smart structures thanks to the versatility of such elements in working as sensors and actuators. The term piezoelectric shunt damping encompass a large variety of techniques for which an electrical impedance, passive or low-powered, is connected to a structurally bonded transducer in order to dissipate the vibration energy converted by the piezoelectric effect. The implementation of these efficient techniques in real structures impels the realization of numerical models capable of providing accurate predictions of the system dynamics. In the case of multilayered, composites and sandwich structures, low-order simplified models are often unable to meet this requirement and more refined approaches are mandatory. The aim of this work is to analyse and demonstrate the validity of the most common piezoelectric shunt damping techniques in the application to the vibroacoustic analysis of multilayered plates. This is accomplished by developing an advanced Finite Element model based on the Carrera’s Unified Formulation that employs a powerful notation to handle in a versatile manner a large variety of two-dimensional plate theories. The vibro-acoustic response is formulated in terms of acoustic radiation modelled with elementary radiators. The model is presented in its mathematical derivation and it is validated through numerical examples found in the related literature. The importance of employing refined theories in the case of structures with a high degree of anisotropy like composite laminates and sandwich plates, is demonstrated by analysing the effects of the model accuracy on the design of the shunt circuit parameters and, consequently, on the efficiency of the corresponding damping techniques.