Thermally induced vibration control of composite plates and shells with piezoelectric active damping

A coupled piezoelectric field is modelled with an expansion strain in the numerical formulation to analyse piezohygrothermoelastic laminated plates and shells. Finite element actuator and sensor equations are derived using a nine-noded field consistent shallow shell element. Thermally induced vibration control is attempted using piezoelectrically developed active damping. The influence of piezoelectric anisotropy on active damping is evaluated, adopting a simple modelling technique. With 40% reduced actuation capability in the lateral direction, the directionally active lamina is observed to be equally efficient in controlling the vibration. In general, the directionally active lamina is efficient if the primary actuation direction is oriented along the fibre direction or in the direction of bending. The directional actuation appeared to be more effective in the velocity feedback control for cantilevered plates and shells. However, in the simply supported case, a balanced actuation effort is required to provide better controllability, which can be achieved by tailoring the directional actuation. The importance of geometric curvature for the actuator performance is also highlighted.