Bioinspired periodic panels optimized for acoustic insulation

TL;DR

This paper introduces bioinspired, optimized periodic panels with locally resonant elements that significantly enhance acoustic insulation, demonstrating robustness against incident angle variations for practical applications.

Contribution

It extends previous shape optimization methods to include locally resonant attachments, improving sound insulation performance and robustness of acoustic panels.

Findings

Locally resonant panels outperform thickness-varying profiles in angle robustness.

Optimized panels effectively inhibit flexural wave propagation.

Numerical models confirm improved acoustic insulation performance.

Abstract

The design of structures that can yield efficient sound insulation performance is a recurring topic in the acoustic engineering field. Special attention is given to panels, which can be designed using several approaches to achieve considerable sound attenuation. Previously, we have presented the concept of thickness-varying periodic plates with optimized profiles to inhibit flexural wave energy propagation. In this work, motivated by biological structures that present multiple locally resonant elements able to cause acoustic cloaking, we extend our shape optimization approach to design panels that achieve improved acoustic insulation performance using either thickness-varying profiles or locally resonant attachments. The optimization is performed using numerical models that combine the Kirchhoff plate theory and the plane wave expansion method. Our results indicate that panels based on locally resonant mechanisms have the advantage of being robust against variation in the incidence angle of acoustic excitation and, therefore, are preferred for single-leaf applications.