This paper deals with nonlinear
feedback stabilization problem of a flexible beam clamped at a
rigid body and free at the other end. We assume that there is no
damping and the feedback law proposed here consists of a nonlinear
control torque applied to the rigid body and either a boundary
control moment or a nonlinear boundary control force or both of
them applied to the free end of the beam. This nonlinear
feedback, which insures the exponential decay of the beam
vibrations, extends the linear case studied by Laousy et al. to
a more general class of controls.