Abstract
The coupling loss factors frequently used in statistical Energy
Analysis are often based on awave approach that assumes that the
transmitted waves returning to the junction are uncorrelated with
the directly transmitted waves. This assumption is generally not
fulfilled forstructures at low frequencies where the response
exhibits distinctly well separated resonances. A method is
presented here for calculation of an improved coupling loss
factorfor one-dimensional subsystems. By applying statistical
considerations to an analyticalexpression for the net power
transmission it is possible numerically to calculate an
averagevalue of the ratio of reflected to incident wave amplitudes
at the junction. From this ratio animproved coupling loss factor
can be calculated which takes into account the re-radiationand
re-injection of power which normally occurs between two
reverberant fields. This improved coupling loss factor has the
following features: it is valid at low modal overlap, it
isindependent of the exact boundary conditions, it depends upon
the loss factor of thereceiving subsystem, and its calculation is
not dependent on the strength of the coupling. Toillustrate the
method, a specific beam system is considered in the frequency
range where themodal overlap is small. Coupling loss factors are
calculated and are employed in a traditionalSEA model to predict
mean square velocities for each beam element with good accuracy.
Original language | English |
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Journal | Journal of Sound and Vibration |
Volume | 212 |
Issue number | 5 |
Pages (from-to) | 829-854 |
ISSN | 0022-460X |
Publication status | Published - 1998 |