Abstract
<title>Abstract</title> <p>Purpose: This study investigates the dynamic response of heterogeneous chiral meta-lattices in which spatial contrast between the bandgap characteristics of geometrically related unit cells is used to prescribe elastic-wave transport regions. Methods: Square lattice unit cells reinforced with auxiliary beam elements are first analysed using the Spectral Finite Element Method (SFEM) in conjunction with the Wittrick–Williams algorithm to establish the dispersion relations and complete bandgaps. Three chiral unit-cell variants are subsequently identified that possess markedly different bandgap distributions while retaining closely matched static in-plane stiffnesses. The predicted bandgap behaviour is verified through finite-lattice frequency-response analyses and comparison with Abaqus simulations. Results: The band-edge mode shapes showed that the selected bandgaps arise from distinct flexural deformation mechanisms associated with the auxiliary members and the primary square frame. By spatially embedding the propagative variants within the host lattice operating within a bandgap, continuous elastic-wave transport regions were formed with prescribed width and trajectory. One- and three-unit-cell-wide channels were demonstrated for both straight and sharply bent configurations. The same heterogeneous-lattice response was extended to frequency-selective routing. Two excitation frequencies were selectively transmitted through distinct straight and bent channels in a single meta-lattice, for both narrow and wide channel configurations. Conclusion: Overall, the results establish bandgap contrast between geometrically related chiral unit cells as a mechanism for controlling the spatial extent, trajectory and frequency selectivity of elastic-wave transport in architected lattices.</p>