Investigation of Meta-structures' Influence on Guided WaveProperties in Nondestructive Testing

This study explores the application of periodic structures (metamaterials) for energy focusing and mode transformation in guided waves, focusing on high-frequency Lamb wave modes. Building upon prior research, which demonstrated the ability of Meta-structures to manipulate low-frequency modes, this study shifts its focus to high-frequency mode propagation. The research utilizes the semi-analytical finite element (SAFE) method and boundary conditions to analyze the dispersion and modal characteristics of the designed periodic structure's unit cells. By optimizing the Meta-structure's geometry, we aim to mitigate energy attenuation and concentrate wave energy in high-frequency modes. Experimental validation confirms the potential of Meta-structures to amplify high-frequency guided waves, enabling more precise defect detection over shorter propagation distances [3]. While challenges in dispersion and energy loss remain, this study highlights the versatility of Meta-structures in manipulating both low- and high-frequency guided wave behaviors. These findings expand the scope of guided wave applications in nondestructive testing (NDT) and structural health monitoring (SHM), advancing the development of wave-based inspection techniques.