Active damping of laminated plates by skewed piezoelectric patches

In the paper the problem of active damping of transverse vibration of a rectangular viscoelastic laminated plate by piezoelectric elements with skewed material axes is studied. The symmetric specially orthotropic and simply supported laminate is subjected to a harmonic excitation. The control system consists of rectangular piezoelectric patches parallel to the plate edges, glued to the upper and lower plate surface and working as the sensor and actuator with a velocity feedback. The dynamic analysis is based on the classical laminated plate theory and the static-coupling model with the assumption of perfect bonding. Due to this model the interaction between the actuator and the laminate can be approximated by the equivalent moments uniformly distributed along the actuator edges. Considering the orthotropic electromechanical properties of the piezoelectric material and two-dimensional piezoelectric effect develops the analysis. The governing equations of the system are formulated for a non-zero skew angle between the natural axes of the piezoelectric material and the plate reference axes. The numerical results in terms of the frequency response show the influence of applying the skewed piezoelectric elements on the efficiency of active damping of transverse displacements.