A COMPARISON OF REACTION FORCE SUPPRESSION TO DISPLACEMENT SUPPRESSION FOR VIBRATION CONTROL IN A FLEXIBLE STRUCTURE

摘要

Vibrations in structures can lead to a number of problems, not the least of which can be fatigue failures from excessive long term cyclic stresses. Passive techniques for vibration control, though sometimes limited in their capabilities, have been the primary method used in the past to attenuate vibrations. Recently active techniques have been developed to provide vibration control performance beyond that provided by their passive counterparts. Most often, the focus of active control methods has been to suppress displacements, and little attention has been given to their effect on structural loads. This paper presents an analytical and experimental study in which two optimal vibration control methods, displacement control and reaction force control, are compared in their effect on displacements and reaction forces in a flexible structure. It is shown that each control method is effective in meeting its specific control objective, and that the two control approaches have greatly different effects on the reaction forces in the system. Depending on the disturbance frequency to be suppressed, the displacement control method in some cases can drastically increase the reaction forces. (C) 1997 Academic Press Limited. [References: 15]