Insights into acoustic properties of seven selected triply periodic minimal surfaces-based structures: A numerical study

Abstract

Poly(methyl methacrylate)-based triply periodic minimal surfaces (TPMS) structures promise great potential in phononic applications, but the complicated TPMS structure induces a design challenge for controlling their properties. Numerical acoustic simulations of seven major PMMA-based TPMS lattice structures are presented for low-frequency sound attenuation applications while varying their relative density. Except for the local resonances in primitive and Neovius-based lattice structures, the acoustic properties of other TPMS structures show a common Bragg bandgap with a central frequency of around 435 Hz and a bandwidth of around 286 Hz, which results from multiple scattering of periodic unit cells. In contrast, the acoustic bandgaps of primitive and Neovius-based lattices have much smaller and larger complete bandgaps, respectively, which are mainly attributed to the local resonances in their geometric cavities with different sizes. Thus, by taking the mechanism of generated bandgaps in the TPMS-based lattice structures into consideration, we can design suitable bandgaps for acoustic applications in the specific frequency range.

Three-dimensional phononic crystals with self-similar structures

“…Phononic crystals with self-similar structures not only have multi-scale structures compared to traditional phononic crystals but also have wider elastic wave bandgaps and better wave control effects [20]. Even with the same material and cell size, more complex structures still have a better chance of possessing superior elastic wave bandgaps [21]. Mousanezhad et al [22] significantly improved bandgap features by applying fractal theory to the hierarchical evolution of regular honeycomb structures.…”

Elastic wave control in reticulated plates using Schwarz primitive cells

“…The Schwarz primitive cell has previously been investigated for its buckling characteristics [26], numerically and experimentally validated for topological elastic wave guiding [27], and has also been explored for vibration mitigation purposes in the realm of acoustic black holes [28]. An in-depth investigation on the relationship between the volume ratio and bandgap behaviour [29], as well as the acoustic properties of Schwarz primitive cell [30] and mechanical vibration bandgaps [31], have been performed. Despite such different types of investigations on the dynamic properties of the Schwarz primitive cell in the context of acoustic and elastic metamaterials [29][30][31][32], their potential in the realm of focusing and mitigation of elastic waves has not been thoroughly studied.…”

“…An in-depth investigation on the relationship between the volume ratio and bandgap behaviour [29], as well as the acoustic properties of Schwarz primitive cell [30] and mechanical vibration bandgaps [31], have been performed. Despite such different types of investigations on the dynamic properties of the Schwarz primitive cell in the context of acoustic and elastic metamaterials [29][30][31][32], their potential in the realm of focusing and mitigation of elastic waves has not been thoroughly studied.…”