Non-uniform control moments induced by a new photostrictive actuator design applied to plate control

Based on the photovoltaic effect and the converse piezoelectric effect, the lanthanum-modified lead zirconate titanate (PLZT) actuator exhibits a photostrictive effect when subjected to certain wave-length light illuminations. Thus, it can be used for non-contact precision excitation and vibration control of smart structures, e.g., shells and plates. In order to improve the control effectiveness, a new actuator design which consists of four regions of PLZT actuator is proposed and evaluated. Due to its polarized direction and uneven boundary conditions of each region, this new actuator can induce non-uniform control forces and moments. Based on the variation method, the approximate distribution curves of the control forces and moments are calculated. Modal control effects of this new actuator on rectangle and square plates are calculated respectively by using the modal expansion method. The influence of actuator size on control effect is also calculated. The comparison between the control effects of this new actuator and those of a multi-DOF actuator shows that due to the non-uniform control moments, the new actuator induces better modal control effects on certain plate modes than those of the multi-DOF actuator.