Effect Of End Conditions On The Active Control Of Beam Vibration

Abstract

The applicability of using vibration acceleration amplitude as the cost function for an active control system designed to minimize harmonic flexural vibration of a beam of finite and semi-infinite length is examined theoretically. Modal analysis is avoided by developing a simple analytical method for calculating the response of a beam to a point-force excitation. This analysis is used to examine a wide range of boundary conditions and to study the effect of these boundary conditions on the control results. The boundary conditions of the beam are described in terms of boundary impedances, and the behaviour of infinite length beams is simulated by choosing infinite beam wave impedance values which produce no reflections. Differences between the controlled behaviour of finite length, semi-infinite and infinite beams are examined and described qualitatively in terms of the physical mechanisms involved.