Design and bandgap optimization of multi-scale composite origami-inspired metamaterials.

This paper seeks to present the design and bandgap optimization of multi-scale composite origami-inspired metamaterials (MCOMs) reinforced with grapheme platelets (GPLs) and carbon fibers. The MCOMs are constructed with a series of hybrid origami single-configuration that spatially reconfigure within prescribing valley and mountain lines. A semi-analytical periodic spectral plate method for the wave analysis of two-dimensional (2D) periodic origami-inspired metamaterials is proposed based on the Mindlin plate theory, higher-order spectral elements, and the Bloch theorem. Various significant parameters, including the weight fraction of GPLs, the volume fraction of carbon fibers, and the fiber orientations, are considered to investigate wave propagation in MCOMs. The results indicate that complete bandgaps (BGs) can be realized in MCOMs with three different spatial configurations, and distributions of nano-reinforced materials cause extraordinary changes in band structures. Subsequently, given that the BG at low frequencies is more attractive in practical engineering applications, the main objective of this paper is to maximize the sum of bandwidths of the first and second BGs employing various significant parameters. The optimization framework is suggested by incorporating the semi-analytical method in an optimization scheme based on particle swarm optimization (PSO). The design objective of MCOMs with three different spatial configurations generated from the proposed method achieves 185.6%, 10.2%, and 61.5% improvement compared with that obtained from the initial design, respectively, which proves that the proposed novel MCOMs and non-uniform distributions of nano-reinforced materials are quite effective for broadband wave attenuation. This work can provide a new thought for designing novel composites and metamaterials. [Display omitted] • A semi-analytical method suitable for two-dimensional periodic origami-inspired metamaterials is proposed. • Band structures and vibration transmittance of multi-scale composite origami-inspired metamaterials are investigated. • The optimization framework is established by incorporating the semi-analytical method in particle swarm optimization. • The non-uniform distributions of the reinforcements can significantly broaden the bandwidths of bandgaps. [ABSTRACT FROM AUTHOR]