INFLUENCE OF PARAMETRIC VARIATION IN BANDGAPS FOR ONE- DIMENSIONAL STRUCTURES

Resumo

In engineering projects where the noise reduction or vibrations is desired, some control methodologies
are applied in order to provide safe and comfortable environments. For that, structural dynamic analysis is done to
verify the effects of wave propagation in the structure. Focusing on this analysis, a parametric variation on elastic
rods phononic crystals (PCs) was performed. The rods are made by two types of materials spatially distributed
periodically along its length. Each period will form a cell, in which was made the variation of the proportion of
each material in order to observe its influence on the bandgap formation. Another approach to have the formation
of the bandgap was the variation of the cross section of the cell. Those analyses were made both separately and
assembled. It was used the Spectral Element Method – SEM to obtain the results. FEM was used to validate the
results. Then, it was possible to obtain the rod behavior due the change of the proportion of materials and cross
section. In the case of the two variations there was a coupling of Bragg scattering effect, allowing both an increase
in its frequency band and in the attenuation level.