On-Line Parameter Control of Nonlinear Flexible Structures

The use of passive auxiliary mass dampers [1], in which a relatively small auxiliary mass is attached to the primary system by a resilient element, to attenuate the response of oscillating systems has long been a standard method for vibration control. The dynamic vibration neutralizer (DVN), also known as the Frahm damper, is a leading member of the sub-class of linear dampers. Its principle of operation relies on the "tuning" of the auxiliary mass so that under steady-state conditions it will generate an opposing force capable of appreciably neutralizing the motion of the primary system. Another member of this group of devices is the Lanchester damper which relies exclusively on mechanical energy dissipation obtained by making the coupling resilient element consist solely of a viscous dashpot.