Transmission Loss formulas for junctions taking into account in-plane waves

In the transmission of vibrations through structural junctions at high frequencies, the distribution of energy between wave types con su er important variations. It means, for example, that incoming energy concentrated in a bending wave (out-of-plane vibration) can be split in transmitted energy of other wave types: bending, quasi-longitudinal or transverse shear waves. The goal of the research is to provide simple formulas to include this phenomenon in a Statistical Energy Analysis (SEA) model through the Coupling Loss Factor (CLF) coe cients. A large number of simulations of a population of junctions is generated by means of a numerical model. Afterwards, this data is post-processed in order to obtain the Transmission Loss (TL) between the di erent wave types by means of a procedure that mimics the Experimental SEA (it is ESEA with some modifications because in the numerical simulations, the internal loss factor is imposed a priori). Each junction is characterised by means of a parameter that minimises the scattering of the TL data with respect to the approximation formula. Some application examples to building structures are shown.