Bloch wave filtering in tetrachiral materials via mechanical tuning

TL;DR

This paper investigates wave filtering in tetrachiral materials by comparing different modeling approaches and tuning microstructural properties to achieve desired acoustic dispersion characteristics.

Contribution

It introduces a comprehensive comparison of synthetic and continuum models for tetrachiral structures and demonstrates mechanical tuning for effective wave filtering.

Findings

Synthetic lagrangian beam-lattice model accurately predicts dispersion spectra.

Mechanical tuning of microstructure enables control over low-frequency band gaps.

Validated wave filtering functionality through parametric analysis and model comparison.

Abstract

The periodic cellular topology characterizing the microscale structure of a heterogeneous material may allow the finest functional customization of its acoustic dispersion properties. The paper addresses the free propagation of elastic waves in micro-structured cellular materials. Focus is on the alternative formulations suited to describe the wave propagation in the material, according to the classic canons of solid or structural mechanics. Adopting the centrosymmetric tetrachiral microstructure as prototypical periodic cell, the frequency dispersion spectrum resulting from a synthetic lagrangian beam-lattice formulation is compared with its counterpart derived from different continuous models (high-fidelity first-order heterogeneous and equivalent homogenized micropolar continuum). Asymptotic perturbation-based approximations and numerical spectral solutions are cross-validated. Adopting the low-frequency band gaps of the material band structures as functional targets, parametric analyses are carried out to highlight the descriptive limits of the synthetic models and to explore the enlarged parameter space described by high-fidelity models. The final tuning of the mechanical properties of the cellular microstructure is employed to successfully verify the wave filtering functionality of the tetrachiral material.