Numerical studies on composite meta-material structure for mid to low frequency elastic wave mitigation

In the past decade, meta-materials have drawn increasing attention from researchers due to their unique properties, including wave attenuation with potential applications in acoustic engineering. A number of meta-material designs have been proposed for wave attenuation at different frequencies. In this work, a new configuration of chiral honeycomb composites is proposed for the attenuation of mid to low frequency elastic waves in structural applications. The dispersion characteristics of the proposed structure were investigated numerically. The results show that the proposed structure is able to create multiple bandgaps at mid frequency range. Interestingly, two extra bandgaps induced by local resonance effect can be created with slight reduction of the chiral angle of the structural unit cell, and one bandgap is located in the low frequency range. The wave attenuation performance of the proposed composite structure was also simulated using sound transmission loss finite element analysis, demonstrating its potential in real applications.