Abstract
This paper discusses a concept for controlling flexural vibration of a beam in which a pin support oscillates harmonically parallel to the beam’s axis. This induces a periodic fluctuation of the effective inertia and stiffness, which represents a source of parametric excitation. A model of the response is developed by using a Ritz series modified to allow the basis functions to be time, as well as position, dependent. Solutions are obtained by numerically integrating the equations of motion. Vibration control requires identification of the support frequency, amplitude, and phase angle that reduce the overall motion relative to what would be obtained if the support were stationary. It is shown that resonances can be controlled in this manner. However, the concept is shown to be ineffective for broadband vibration reduction because the parametric excitation merely shifts the resonant frequencies, while it also induces new resonances.
