بررسی تاثیر انواع جهت‌گیری‌ها و شکل گردنه در فراماده صوتی C-شکل

Acoustic metamaterials are innovative materials with engineered structures that allow for the control and manipulation of sound waves beyond the limitations of conventional materials. These materials have garnered significant attention in scientific and industrial research due to their ability to reduce noise, enhance sound quality, and create unique acoustic properties. In this study, the impact of geometry and orientation of the neck in a C-shaped acoustic metamaterial, which has a bandgap caused by Helmholtz resonance, is investigated. This bandgap results in a reduction of sound transmission (STL) within the resonance frequency range. Numerical simulations using COMSOL software have been conducted to analyze this structure. The neck shapes include filleted, outward-facing, inward-facing, with a side edge, with a square edge, and with a circular edge. The effects of these variables on the frequency and intensity of sound transmission loss in the Helmholtz resonance range have been examined and the results analyzed. For validation, a sample of this metamaterial was fabricated using 3D printing, and its simulation results were compared with experimental test data. The findings of this study can provide valuable guidance for the optimal design of acoustic metamaterials for specific applications, such as sound insulation and frequency filters.