WAVE AND FINITE ELEMENT ANALYSIS OF QUASI PERIODIC 2D PHONONIC SUPER-CELL CRYSTALS

aeronautical industries since they introduce frequency stop-bands (frequency ranges where wave cannot freely propagates). In this investigation 2D periodic and quasi-periodic pattern: instead of strictly repeating a pattern, a certain degree of irregularity is introduced. Quasi-periodic PCs in this paper are defined as assemblies of two different elements in two direction by using Thue-Morse and semi-Sierpinski carpet which results in asymmetry in both directions. Numerical studies on periodic and quasi-periodic lattices are performed. The spectral analysis in periodic waveguide is validated with the dispersion diagram of a reference model and vibration transmission of the lattices are studied. The wave characteristics in quasi-periodic super-cell configuration increases the wide of band-gaps about 22% compared to the reference model. Nevertheless, the associated level of vibration in the forced response of quasi-periodic lattices are predicted.