A nonlinear active vibration damper has been developed which uses a spatially distributed piezoelectric actuator, polyvinylidene flouride, to achieve active vibration control of a cantilever beam. The control algorithm was derived using Lyapunovs Second Method. All modes of the beam can be controlled simultaneously if the angular velocity of the tip of the beam is known. A simulation algorithm was developed to predict the effect of the control on the free decay of a single mode. A parameter study for the first mode was performed and compared to experimental results. The active damper has been tested successfully on two different scale structures.