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Effect of Strain Fields on Frequency Band Gaps of Periodic Lattice-Based Metamaterials
Shendy, Mohamed Alkhader, Maen Abu-Nabah, Bassam Venkatesh, T.A.
Shendy, Mohamed
Alkhader, Maen
Abu-Nabah, Bassam
Venkatesh, T.A.
Date
2024-11
Advisor
Type
Article
Degree
Description
Abstract
Lattice-based metamaterials, known for their ability to deliver unique acoustic properties such as wave band gaps and direction-dependent phase velocities, are considered promising for noise filtering and acoustic sensor applications. Lattice-based metamaterials’ unique acoustic abilities arise from their periodic porous structures, allowing them to be realized even when the lattices are made from isotropic materials. The properties of lattice metamaterials are primarily determined by their inner microstructure (i.e., topology and morphology). Consequently, by designing their inner microstructure, it is possible to tune their properties to filter or detect specific frequencies. Varying the topology of lattice metamaterials has been shown to affect their acoustic properties significantly. However, this work focuses on the effect of morphological changes, particularly stretching, on their acoustic properties. Stretching can be achieved by mechanically deforming lattice metamaterials using external forces or by constructing them from active constituents such as piezoelectric materials. The overall goal of this work is to assist in developing lattice metamaterial that can deliver deformation-tunable acoustic properties. This work computationally investigates the effect of stretching strain fields on a hexagonal lattice-based metamaterial. In particular, it examines the effects of small and large strain fields on the frequency band gaps between 100kHz and 1000kHz. Different strain levels are used to determine the sensitivity of frequency band gaps to stretching strains. The results show that the frequency band gaps are insensitive to small strains at low frequencies (~100kHz) but are sensitive to small strains at higher frequencies (~1000kHz). Conversely, large strains significantly affect the frequency band gaps, resulting in the shift, creation, or cancelation of band gaps. The findings demonstrate that actuating lattice-based metamaterial can effectively tune their frequency band gaps.