Modeling and dynamic behavior of rotating blades carrying a tip mass and incorporating adaptive capabilities

Abstract

The problems of the mathematical modeling and dynamical behavior of rotating blades carrying a tip mass and incorporating adaptive capabilities are considered. The blade is modeled as a thinwalled beam incorporating non-classical features such as anisotropy, transverse shear, secondary warping, and includes the centrifugal and Coriolis force fields. For non-adaptive rotating blades, a thorough validation of the structural model and solution methodology is accomplished. The adaptive capabilities provided by a system of piezoactuators bonded or embedded into the structure are also implemented. Based on the converse piezoelectric effect, the piezoactuators produce a localized strain field in response to an applied voltage, and, as a result, an adaptive change of the dynamic response characteristics is obtained. A combined feedback control law relating the piezoelectrically induced bending moment at the beam tip with the kinematical response quantities appropriately selected is used, and its beneficial effects upon the closed-loop eigenvibration characteristics are highlighted.