A hybrid radiative transfer and statistical energy analysis theory for point-coupled subsystems

This article presents a hybrid theory in sound and vibration, unifying statistical energy analysis (SEA) and radiative energy transfer theory for point-coupled two-dimensional subsystems excited by stationary random forces. It is designed to bridge the gap between the domains in which the vibrational field is diffuse and where it is not a result of a high damping. The theory extends the applicability of SEA beyond its traditional range, addressing limitations posed by nonhomogeneous energy distribution and point coupling between subsystems. The reformulation of the radiative transfer equation for point-coupled subsystems is a central focus, providing a solution to the singularity issue in the energy kernel. A test case of two plates coupled by a spring demonstrates the efficiency of the hybrid model, showing good agreement with reference calculations.