SEA Parameter Estimation Based on a Modal Approach

This paper concerns the higher frequency vibrations of complex built-up structures, in particular, the problems involved in predicting the Statistical Energy Analysis (SEA) coupling loss factors by the conventional SEA theory. A modal approach is used to quantify the coupling strength between two coupled subsystems through an arbitrary interface. Inter-modal dynamic coupling stiffness analysis can then cast the coupling strength into two categories: (1) strong coupling, and (2) weak coupling. In the weak coupling region, the two subsystems can be treated simply as two sets of coupled oscillators, each subsystem mode being simulated as one oscillator. The results can then be accommodated within the conventional SEA procedure to predict the SEA parameters, e.g., coupling loss factors, in a simpler and more systematic way. A rod-rod coupling example is presented to illustrate the validity of the approach.