Wave Attenuation in Damped Periodic Structures.

It is known that periodic structures will act as filters for bending waves. The equations for an infinite ribbed bar have been published. The objective of this study is to get extensive quantitative results, both analytical and experimental, for a finite number of tuned ribs and to extend the work to plates and possibly shells. In the process, we intend also to investigate the differences between symmetric two-sided and asymmetric one-sided cantilever ribs. This first technical report gives analytical and experimental results for the uniform bar unribbed and for the same bar with fifteen pairs of tuned cantilevers which approximates the infinite ribbed bar.