NONLINEAR-ANALYSIS OF COMPOSITE THIN-WALLED HELICOPTER BLADES

Nonlinear theoretical modeling of laminated thin-walled composite heli copter rotor blades is presented. The derivation is based on nonlinear geometry with a detailed treatment of the body loads in the axial dir ection which are induced by the rotation. While the in-plane warping i s neglected, a three-dimensional generic out-of-plane warping distribu tion is included. The formulation may also handle varying thicknesses and mass distribution along the cross-sectional walls. The problem is solved by successive iterations in which a system of equations is cons tructed and solved for each cross-section. In this method, the differe ntial equations in the spanwise directions are formulated and solved u sing a finite-differences scheme which allows simple adaptation of the spanwise discretization mesh during iterations.