Acoustic Waves in Two-Dimensional Phononic Crystals With Reticular Geometric Structures

Previous studies on photonic crystals raise the exciting topic of phononic crystals. This paper presents the results of tunable band gaps in the acoustic waves of two-dimensional phononic crystals with reticular geometric structures using the 2D and 3D finite element methods. This paper calculates and discusses the band gap variations of the bulk modes due to different sizes of reticular geometric structures. Results show that adjusting the orientation of the reticular geometric structures can increase or decrease the total elastic band gaps for mixed polarization modes. The band gap phenomena of elastic or acoustic waves can potentially be utilized to achieve vibration-free, high-precision mechanical systems, and sound insulation.

Analysis of Frequency Band Gaps in a Plate With Periodic Stubbed Surface

The applications and researches of so-called photonic crystals raise the exciting researches of acoustic wave propagation and frequency band gaps in phononic crystals. The photonic crystal structure can be modeled in two different forms, namely the periodically-repeated dual materials, or a single medium with periodically-repeated stubbed surface. This paper presents the results of the tunable band gaps of acoustic waves in a plate with periodic stubbed surface using the finite element method. Band gaps variations of the plate modes due to different oriented angles of periodic stubbed surface are calculated and discussed. The results show that the elastic band gaps for plate modes can be enlarged or reduced by adjusting the orientation of stubbed surface. The phenomena in this idea can potentially be utilized for the design of new resonance frequency devices.