A Theoretical Basis for the Practical Simulation of Random Motions

Abstract

It is desirable to be able to impose on a given equipment random motions which are effectively equivalent to those observed in a similar equipment in service. Analysis of the response of a body to random excitation leads to the formulation of the conditions for exact spectral simulation in terms of normal co-ordinates. This is made the basis for the formulation of a simplified test in which at all points the predominant constituents of the motion are correctly reproduced. In systems where a single mode predominates at each of the significant frequencies of the motion, simulation may in principle be achieved in a test using a single vibrator.