Analysis of Dynamic Systems Using the Mechanical Impedance Concept

Abstract

The mechanical impedance concept is a powerful tool for the analysis of dynamical structural systems consisting of a single degree-of-freedom unit coupled to an infinite degree-of-freedom unit. Actual systems of interest that approximate this are (1) instrument components coupled through isolators to the vibrating shell of aircraft or missiles with the inherent problem of predetermining the dynamic forces acting upon the component, and (2) vibrating machinery coupled through isolators to the hulls of marine vessels with the inherent problem of minimizing the sound radiating into the sea. Formulas are presented for each case with damping included by rheological models. The quantities of the formulas can be measured if the continuous supporting unit is undefined. Simpler theoretical analyses result for defined continuous units than for the usual classical approaches. No approximations are made beyond those of classical linear continuum mechanics. (This research was supported by Armour Research Foundation.)