This project addresses the control of nonlinearly flexible structures. The intent is to determine stabilizing controls based on the energy-momentum methodology. The system considered comprises a flexible assemblage and a controller. The demand is imposed that a specified state be an equilibrium state, and then the energy-momentum method is used to find conditions which the controller must satisfy, thus characterizing a class of stabilizing controllers. A nonlinear model for the flexible appendage is used and imposes no restrictions on deformation.