Experimental study of non-linear transient motion confinement in a system of coupled beams

An experimental study of non-linear confinement of transient motions in a flexible structure consisting of two weakly coupled cantilever beams with active grounding non-linearities has been carried out. The experimental fixture and the control methodology used for implementing the active non-linearities are discussed in detail. It has been found that the system with active non-linearities possesses motion confinement properties, that is, transient motions originating at one of the beams become spatially confined mainly to the directly excited beam, with small amounts of vibrational energy ''leaking'' to the unexcited one. As the damped motion decays the non-linear effects diminish and the motion confinement phenomenon becomes less evident. The experimental results are in agreement with analytical predictions. The implementation of non-linear motion confinement in vibration and shock isolation designs of repetitive systems is discussed. (C) 1996 Academic Press Limited