Agradecimentos: The authors would like to thank the NT3D group from CTI Renato Archer Brazilian Institute (Campinas-SP, Brazil) for manufacturing the metamaterial beam samples through the ProEXP program, and the Nondestructive Testing Laboratory (LabEND) from FEAGRI/UNICAMP for providing the...

Agradecimentos: The authors would like to thank the NT3D group from CTI Renato Archer Brazilian Institute (Campinas-SP, Brazil) for manufacturing the metamaterial beam samples through the ProEXP program, and the Nondestructive Testing Laboratory (LabEND) from FEAGRI/UNICAMP for providing the ultrasound equipment used to measure the elastic properties of the cube specimens. The authors also grateful to the São Paulo Research Foundation (FAPESP - São Paulo, Brazil), through project numbers 2014/19054-6 and 2015/15718-0, the Federal District Research Foundation (FAPDF - Distrito Federal, Brazil), process number 0193.001507/2017, and the Coordination for the Improvement of Higher Education Personnel (CAPES - Brazil) for the financial support

Additive manufacturing has become a fundamental tool to fabricate and experimentally investigate mechanical metamaterials and phononic crystals. However, this manufacturing process produces spatially correlated variability that breaks the translational periodicity, which might compromise the wave...

Additive manufacturing has become a fundamental tool to fabricate and experimentally investigate mechanical metamaterials and phononic crystals. However, this manufacturing process produces spatially correlated variability that breaks the translational periodicity, which might compromise the wave propagation performance of metamaterials. We demonstrate that the vibration attenuation profile is strictly related to the spatial profile of the variability, and that there exists an optimal disorder degree below which the attenuation bandwidth widens; for high disorder levels, the band gap mistuning annihilates the overall attenuation. The variability also induces a spatially variant locally resonant band gap that progressively slow down the group velocity until an almost zero value, giving rise to wave trapping effect near the lower band gap boundary. Inspired by this wave trapping phenomenon, a rainbow metamaterial with linear spatial-frequency trapping is also proposed, which have potential applications in energy harvesting, spatial wave filtering and non-destructive evaluation at low frequency. This report provides a deeper understanding of the differences between numerical simulations using nominal designed properties and experimental analysis of metamaterials constructed in 3D printing. These analysis and results may extend to phononic crystals and other periodic systems to investigate their wave and dynamic performance as well as robustness under variability

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

0193.001507/2017

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES

2014/19054-6; 2015/15718-0

FUNDAÇÃO DE APOIO À PESQUISA DO DISTRITO FEDERAL - FAPDF

0193.001507/2017

Aberto