WAVE-PROPAGATION IN SEMI-INFINITE PLANE ANISOTROPIC THIN CIRCULAR SHELLS

The problem of propagation of elastic waves in semi-infinite thin circular cylindrical shells has been investigated. The focus of the paper is to bring out the effect of a finite end which forms a boundary of the shell. The shell theory used is a linear theory due to Sanders incorporating a plane anisotropic material model. The frequency equation is viewed as an "end problem", leading to an eigenvalue structure of the system which encompasses both propagating and attenuating modes for a prescribed input excitation frequency at the finite end. The existence of the attenuating modes implies trapping of the part of the energy in the end zone of the shell and thus essentially represents the dynamic counterpart of the well known static Saint Venant effect. The eigenvalue structure is investigated and illustrative numerical examples worked out. The amplitude ratios associated with the various modes of propagation have also been investigated. © 1991.