Design techniques for superposition of acoustic bandgaps using fractal geometries

TL;DR

This paper introduces a novel design technique using fractal geometries to create wide acoustic bandgaps in phononic crystals, enhancing wave control capabilities in engineered materials.

Contribution

The study presents a new method leveraging fractal geometries to achieve wide bandgaps in acoustic phononic crystals, applicable across various wave types and frequency ranges.

Findings

Fractal geometries enable wider bandgaps in phononic crystals.

The technique is applicable to different wave types and frequency ranges.

Potential for improved wave control devices.

Abstract

Research into properties of heterogeneous artificial materials, consisting of arrangements of rigid scatterers embedded in a medium with different elastic properties, has been intense throughout last two decades. The capability to prevent the transmission of waves in predetermined bands of frequencies -called bandgaps- becomes one of the most interesting properties of these systems, and leads to the possibility of designing devices to control wave propagation. The underlying physical mechanism is destructive Bragg interference. Here we show a technique that enables the creation of a wide bandgap in these materials, based on fractal geometries. We have focused our work in the acoustic case where these materials are called Phononic/Sonic Crystals (SC) but, the technique could be applied any types of crystals and wave types in ranges of frequencies where the physics of the process is linear.