ABSTRACT
Helicopter rotor blades are long slender beams undergoing axial, lag, flap, and torsional deformations. Figure 6.1 shows the deformation of an elastic blade model. A detailed analysis of blade dynamics requires the formulation of coupled equations of motion. These equations are nonlinear due to the inclusion of moderate deformation effects, involving nonlinear straindisplacement relationships. Formulation of the equations of motion of the rotor blade has been a topic of research since the 1970s. Earlier theories were restricted to treating the dynamics of isotropic blades; later, in the late 1980s and early 1990s, beam theories suitable for composite rotor blades were formulated. Research efforts are also directed to the development of a multidisciplinary optimization of composite rotor blades.
