Mid-to-high frequency piecewise modelling of an acoustic system with varying coupling strength

Mid-to-high frequency vibro-acoustic modelling has always been a challenging topic. The previous study shows the promise of a piecewise calculation scheme based on the Condensed Transfer Function (CTF) approach in a frequency range where the modal overlap factor roughly exceeds one. The piecewise scheme has shown its capability in terms of balancing the accuracy, efficiency and the wealth of information for the modeling of lightly coupled vibroacoustic systems. This paper extends the method beyond the weak-coupling assumption. A coupling strength factor is first proposed to quantify and adjust the coupling strength between two sub-systems. Two mutually connected sub-cavities are then used as an example to validate the piecewise scheme in relation to the changes in the coupling strength level, as well as the variations in the coupling strength factor itself. The effect of the coupling strength on the computational error of the piecewise scheme is systematically studied. Finally, the applicability of the piecewise calculation scheme is experimentally validated. (C) 2019 Published by Elsevier Ltd.