THE EFFECT OF PERIOD ASYMMETRY ON WAVE PROPAGATION IN PERIODIC BEAMS

✍ Scribed by N.S. Bardell; R.S. Langley; J.M. Dunsdon; T. Klein

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 291 KB
• Volume: 197
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1996.0541

✦ Synopsis

The h-p version of the finite element method is used to study flexural wave motion in a periodic beam with identical, but non-symmetric, periods. The convergence behaviour of the h-p method is benchmark validated against an exact analysis provided by the dynamic stiffness method in obtaining solutions for the wave propagation constant as a function of frequency. It is shown that period asymmetry can have a beneficial effect on the dynamic characteristics of the structure from a vibration control viewpoint and could feasibly be exploited as an additional design variable. It is also demonstrated that, in the presence of asymmetry, the pass-band bounding frequencies no longer correspond to the natural frequencies of an isolated bay. A study of the group velocity of wave motion as a function of frequency in an asymmetric system is also included. The ability to compute this information is important because it enables a direct measure of the energy flow, the modal density of the system, and the rate of spatial decay which is caused by an added damping treatment, to be estimated within a given pass-band.