STATISTICAL ENERGY ANALYSIS OF PERIODICALLY STIFFENED DAMPED PLATE STRUCTURES

Stiffened panels are used widely in aerospace and marine vehicles, and it is often necessary to predict high frequency noise and vibration l evels in structures of this type. The present work is concerned with m odelling high frequency vibration transmission through a stiffened pan el within the context of Statistical Energy Analysis (SEA). It is prop osed that the panel can be modelled as a damped coupling element betwe en two adjoining structural components, and the transmission and absor ption coefficients calculated on the basis of periodic structure theor y. The method is applied to the forced response of two panels which ar e coupled by a stiffened panel and a comparison is made with (i) exact results obtained by using the dynamic stiffness method, (ii) results yielded by a conventional SEA approach, and (iii) results yielded by w ave intensity analysis (WIA). The method is found to yield accurate re sponse predictions which are a significant improvement upon the conven tional SEA and WIA results obtained for the example system. Previous w ork has shown that vibration transmission through a periodic system ca n be very sensitive to structural disorder, and the present study incl udes an investigation of the effects of disorder in the stiffener spac ing. (C) 1997 Academic Press Limited.