The study of a locally resonant beam with aperiodic mass distribution

Abstract To widen the locally resonant bandgap without adding additional mass, a novel locally resonant beam with aperiodic mass distribution is proposed. An evaluation index of unit mass attenuation capability considering both the bandgap attenuation and the bandgap width is proposed, which is more appropriate to assess the propagation characteristics of finite periodic/aperiodic structures. The optimization of mass distribution is realized by the genetic algorithm. The bandgaps generated by this structure are investigated by finite element simulation. And a test of propagation characteristics is conducted to validate the effect of widening the bandgap. The results indicate that this kind of configuration can enlarge the frequency range of bandgaps in flexural vibrations effectively. Finally, the aperiodic structure is applied to the subframe system.