Comparative study on vibration control methodologies applied to adaptive thin-walled anisotropic cantilevers

A study of the vibrational control of adaptive doubly-tapered cantilevered beams, simulating an aircraft wing, exposed to time-dependent external pulses is presented. Whereas the beam structure encompasses non-classical properties such as transverse shear and anisotropy of their constituent materials, the active control capabilities are based upon the implementation of the adaptive materials technology. Herein, the adaptive feature is achieved through the converse piezoelectric effect that consists of the generation of localized strains in response to an applied voltage. Piezoactuators in the form of patches or spread all over the beam span are considered. The active control involves the dynamic response to arbitrary time-dependent external pulses. The closed-loop dynamic response time-histories are obtained via the use of the piezoelectrically induced moment control, and through the implementation of a modified bang-bang control strategy that involves a maximum value constraint imposed on the input voltage. In addition to this active feedback control methodology, a passive one based upon the use of the directionality property of anisotropic composite material structures is also implemented. Moreover, the results are compared to those obtained via the implementation of other two feedback control methodologies, namely the Linear Quadratic Regulator (LQR) and the Fuzzy Logic Control (FLC). Numerical simulations emphasizing the performance of the adopted control strategies intended to contain and even suppress the oscillations when time unfolds are presented, and pertinent conclusions are outlined.