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

The problems of the mathematical modeling and dynamical behavior of rotatin g blades carrying a lip mass and incorporating adaptive capabilities are co nsidered. The blade is modeled as a thin-walled beam incorporating non-clas sical features such as anisotropy, transverse shear, secondary warping, and includes the centrifugal and Coriolis force fields. For non-adaptive rotat ing blades, a thorough validation of the structural model and solution meth odology 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 lo calized strain field in response to an applied voltage, and, as a result, a n adaptive change of the dynamic response characteristics is obtained. A co mbined feedback control law relating the piezoelectrically induced bending moment at the beam tip with the kinematical response quantities appropriate ly selected is used, and its beneficial effects upon the closed-loop eigenv ibration characteristics are highlighted.