Active Minimisation of Vibrational Energy in Periodically Excited Structures

Abstract

In many practical cases the vibration of a structure can be considered as periodic or quasi-periodic in nature. Rotating and reciprocating machinery such as internal combustion engines, a.c. electric motors, gear boxes and aeronautical and nautical propellers are common sources of periodic vibration. Vibration from these machines is transmitted to surrounding structures through the machinery mountings and through acoustic excitation and can result in high levels of noise and vibration at some distance from the source.