VIBRATIONAL-ENERGY FLOWS BETWEEN COUPLED MEMBRANES

The vibrational energy flows occurring between a pair of unequal recta ngular membranes coupled along a mutual edge are investigated. Since t he membranes studied have different properties and form an L shape whe n coupled this calculation may not be carried out directly, instead re quiring some form of approximation. Here, the line coupling is modelle d by a series of point couplings with sufficient points to ensure conv ergence for the frequencies of interest. This L shaped composite membr ane model is then perturbed by the addition of a number of random poin t masses. The effects caused by varying the number and degree of rando mness of the attached masses on the ensemble statistics of the combine d system are subsequently investigated. The statistics of this ensembl e are considered for weak and strong coupling between the membranes an d for point and ''rain-on-the-roof'' type forcing. The existence of en ergy flow vortices in some ensemble members at some frequencies is not ed. Conclusions are drawn for the application of Statistical Energy An alysis (S.E.A.) to coupled two-dimensional subsystems. (C) 1996 Academ ic Press Limited