Broadband sound attenuation of shape memory polymer with triangular-honeycomb unit cell metamaterial structural design

Title : Broadband sound attenuation of shape memory polymer with triangular-honeycomb unit cell metamaterial structural design

Abstract:

Periodic lattice structures using metamaterial design have gained significant research interest recently for elastic and acoustic wave attenuation applications. This study incorporates a triangular reentrant honeycomb unit cell design combining Bragg scattering and local resonance mechanisms into a lattice structure to attenuate sound waves. Sound absorption coefficient and transmission loss were characterized using an impedance tube to investigate the effects of different thicknesses, cell arrangements, and direction of cell opening, for unit cells integrated into 3-D printed lattice structures. A peak sound absorption coefficient of approximately 0.96 was achieved when adopting a combination of different mechanisms, and retention of high sound absorption across the frequency band is also shown. A transmission loss of 12-13 dB was achieved using this metamaterial design. Based on the results attained in this study, a triangular reentrant honeycomb metamaterial design is proposed to be adopted for acoustic noise-absorbing and selective frequency filtration applications.

Biography:

Musa’ab Ejaz is a PhD student in the Department of Mechanical Engineering at Universiti Teknologi PETRONAS (UTP). He earned his Master of Engineering in Mechanical Department from Lehigh University Pensylvania, USA. His research interests include acoustic metamaterials, noise control engineering, and vibroacoustics. He is currently working on using acoustic metamaterial lattice structures with shape memory polymers (SMPs) materials for selective frequency filtration and their applications.