The role of moments on the vibration transmission in built-up structures

Towards the development of simplified analysis methods for the vibrational power in built-up plate structures, a circular can upon an infinite recipie nt plate is considered. The primary aspect considered is the role of the mo ments at the upper and lower interfaces, with respect to both the input and transmitted power. Where the thickness of the cans top-plate is at least t wice that of the side-wall, the moments are shown to have limited influence and, within "engineering accuracy", it is suggested they can be ignored in an analysis. This greatly simplifies the modelling of the system. Moreover , it is also shown that where the side-walls are thick compared to the top- plate and, accordingly, the rotational stiffness at the upper interface hig h, the influence of the moments can, and most simply, be accounted for by m erely imposing a guided boundary condition upon the top-plate. A substantia l simplification results for the modelling of the system and the analysis. Further, it is found that for typical dimensions, there is an extended freq uency range over which the response of the side-walls is either mass or sti ffness controlled Thence, it follows that the input and transfer mobilities of the side-walls are comparable to each other, leading to further reducti on of the models. (C) 1999 Academic Press.