Natural Frequencies and Band Gaps of Periodically Corrugated Beams

Autor(es)

Bachour, Rhamy Salim ^[1] ; Nicoletti, Rodrigo ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Sch Engn, Dept Mech Engn, Trabalhador Sao Carlense 400, BR-13566590 Sao Carlos - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME; v. 143, n. 4 AUG 1 2021.
• Citações Web of Science: 2

Resumo

Structures with geometric periodicity can present interesting dynamic properties like stop and pass frequency bands. In this case, the geometric periodicity has the effect of filtering the propagating waves in the structure, in a similar way to that of phononic crystals and metamaterials (non-homogeneous materials). Hence, by adopting such structures, we can design systems that present dynamic characteristics of interest, e.g., with minimum dynamic response in a given frequency range with large bandwidth. In the present work, we show that corrugated beams also present the dynamic properties of periodic structures due to their periodic geometry only (no need of changing mass or material properties along the beam). Two types of corrugated beams are studied analytically: beams with curved bumps of constant radii and beams with bumps composed of straight segments. The results show that, as we change the proportions of the bump, the natural frequencies change and tend to form large band gaps in the frequency spectrum of the beam. Such shifting of the natural frequencies is related to the coupling between longitudinal and transverse waves in the curved beam. The results also show that it is possible to predict the position and the limits of the first band gap (at least) as a function of the fundamental frequency of the straight beam (without bumps), irrespective of the total length of the corrugated beam. (AU)

• Processo FAPESP: 19/18095-4 - Análise numérico-experimental de rotores com periodicidade geométrica e manufatura aditiva
• Beneficiário: Rhamy Salim Bachour
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 18/15894-0 - Projeto e otimização de estruturas periódicas para aprimoramento de desempenho vibroacústico
• Beneficiário: Carlos de Marqui Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático