Structural damping from random data

Abstract

The usual method of fitting circles to transfer function peaks in the complex plane while yielding reliable estimates of modal damping, is laborious to implement manually and difficult to automate unambiguously. This paper outlines an approach to increasing the efficiency of this operation by combining the topological abilities of a human operator with the numerical power of a computer through an interactive visual display. Transfer functions obtained from structural tests using random acoustic excitation are readily analysed to yield modal damping using this system. [Work performed at the British Aircraft Corporation, Weybridge, Surrey, England.]