Numerical investigations and experimental measurements on the structural dynamic behaviour of quasi-periodic meta-materials. (February 2020)

• Record Type: Journal Article
• Authors: Timorian, S.; Ouisse, M.; Bouhaddi, N.; De Rosa, S.; Franco, F.
• Is Part Of: Mechanical systems and signal processing. Volume 136(2020)
• Publication Date: 2020-02
• Subjects: Quasi-periodic structures -- Band diagram -- Frequency stop-band -- Forced response -- Metamaterials; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2019.106516
• Languages: English
• ISSNs: 0888-3270

Abstract

Highlights: The Thue-Morse morphism sequence is capable of providing 2D quasi-periodic pattern. Predicted stop bands of infinite lattice matches the forced response of finite model. Experimental measurements validate the results obtained by finite element model. Degree of consistency between numerical & experimental results are highly predicted. FRF of the meta-structure (junction filter) reduces maximum unwanted vibration. Abstract: The periodic structures have various applications in vibroacoustic engineering fields since they introduce frequency band effects due to the periodic discontinuities in the geometrical or material configurations: this can lead to increased performances. This paper is focused on the analysis of quasi-periodic structures: instead of using strictly repeated patterns, a certain degree of irregularity is introduced. Quasi-periodic lattices are defined as assemblies of two different elements in two directions. The assembly follows a Thue-Morse Morphism sequence which results in asymmetry in both directions. Numerical studies and experimental measurements on two-dimensional periodic and quasi-periodic lattices are thus performed. First validations are carried out by comparing the quasi-periodic lattice modelled by using finite element model with a prototype manufactured by laser machine. The wave characteristics in quasi-periodic lattice introduce elements of novelty for designing wider frequency stop bands in low frequency ranges.