These panels have been earlier analyzed for their dynamic behavior to predict their natural frequencies and mode shapes. Many researchers have extensively conducted experimental measurements to measure sound transmission loss of such panels. Few of the researchers have experimentally measured the radiation efficiency of sandwich structures. They have been analyzed for sound transmission prediction using infinite panel theory. In real applications, only finite panels are used.
Finite panels behave differently in the frequency region below the critical frequency.
Infinite panel theories can not take into account these effects of finite panels. In the present analysis, effects of finite panels are considered Modal densities of the composite panels are predicted. Effect of the surrounding air on the stability of the contact line''. The main limitation is air entrainment which may induce catastrophic defects. Contrarily to the classical approaches, we take into account the third phase, namely the air.