Aplicação de barras periódicas tubulares para atenuação de vibrações

Abstract

In the last years, it is observed an increasing number of publications on the application of periodic structures to attenuation of structural vibration. These sctructures are composed with identical elements or parts connected repeatedly. The design of this type of structure can be used to achieve frequency bands in which there is no propagation of elastic waves, called "stop bands", introducing an effect similar to that of a mechanical filter. In this context, this work has objective to present an approach for the design of tubular periodic bars aimed at the attenuation of longitudinal vibrations in frequency bands defined by design requirements. For this, is used an methodology which relacts state vectors and the longitudinal wave amplitude. Two types of periodic tubes are evaluated, one with periodicity of the geometric type and another of the compound type. Experimental tests are performed and the results are very similar to those obtained numerically. Moreover, the results show that the applied holes in the structure promote expressive stop band gains, and also a reduction in the structure’s mass. Ultimately, this work presents tech- niques that may be utilized in projects of periodic tubular rods aiming vibration supression.