A method of analyzing finite periodic structures .2. Comparison with infinite periodic structure theory

The relations between the proposed method for analyzing finite periodic structures and the theory of infinite periodic structures are discussed. It is shown that the proposed method is in fact a very useful approximate approach for calculating not only the natural frequencies and modes of finite periodic structures but also the pass-bands of infinite periodic structures as a function of the phase constant. The pass-bands of various periodic beam structures are calculated. The discussion focuses on the influence of stiffeners on the pass-bands of the structures, and provides some useful indications of the possibilities and limitations of tuning a pass-band of a periodically stiffened structure by means of tuning the properties of the stiffeners. The example calculations show that it is possible to use stiffeners to change the location and width of the lower order pass-bands. (C) 1997 Academic Press Limited.