A Study on Guided Wave Propagation in Quasicrystal Plates

Abstract

Guided wave-based Structural Health Monitoring (SHM) is a highly promising approach for assessing the structural integrity of large-scale engineering systems. This method offers significant advantages, including rapid and extensive area monitoring, long-distance wave propagation, the capability to detect internal damage, and low energy consumption. Quasicrystals are recent advancements in materials characterized by low frictional and adhesion coefficients, along with high abrasion and thermal resistance. These properties make them highly suitable for coating surfaces in various engineering applications. In quasicrystals, the quasi-periodic atomic arrangement introduces additional phason displacement modes alongside phonon modes, presenting a unique challenge in guided wave analysis. In this work, the semi-analytical finite element (SAFE) method has been implemented for computing dispersion curves, phase and group velocities for quasicrystals. These methods have advantage in wave propagation analysis for complex cross section where analytical solution is difficult to obtain. Using the SAFE, a novel eigenvalue formulation has been developed for established quasicrystal models in literature: Bak’s model and Lubensky’s model. This study focuses on understanding how phason modes behave in Lamb wave analysis and also understanding how phononphason coupling constant has effect on Lamb wave analysis. Results have been obtained for various phason elastic constants reported in literature.