DETERMINATION OF STATISTICAL ENERGY ANALYSIS LOSS FACTORS BY MEANS OF AN INPUT POWER MODULATION TECHNIQUE

摘要

An input power modulation technique is proposed as an alternative to the widely used steady-state power injection method for the in-situ determination of dissipation and coupling loss factors of subsystems selected for an SEA model of a physical system. There is no requirement to measure input power and, in principle, response measurements are made at only one point on each subsystem. Theory is developed for a two-subsystem model. An input power modulation device is described, and the loss factor estimates resulting from its application to systems comprising two structurally coupled plates and two acoustically coupled rooms are presented and compared with those from steady state tests. A phenomenon of energy response modulation phase dispersion is observed at modulation frequencies in excess of about 10 Hz. (C) 1997 Academic Press Limited. [References: 11]