Session: 05-01: Guided Waves I

Paper Number: 135257

135257 - Metamaterial Manipulation of Lamb Waves for Nondestructive Evaluation 

Abstract: 

Previous research has demonstrated that metamaterials can be used to manipulate guided waves in thinwalled structures. This manipulation can redirect the wave or focus energy to a given location prior to capture by a sensor and therefore increase the signal-to-noise ratio of the detected signal. These metamaterials are generated by the periodic repetition of a unit cell which changes the local velocity of the guided wave as it passes the unit cell. The dimensions of the unit cell determine the frequencies for which this manipulation is effective on the guided wave. For many approaches, the complexity of the unit cell is limited by the practical need to fabricate small feature sizes within the unit cell. In this technical presentation we will present different until cell design geometries and their effects on Lamb waves in a thin-walled structure. We demonstrate several example unit cells, based on multiple materials and resonance effects, while still being within the limits of practical fabrication using 3D printing methods. The local velocity for each unit cell is calculated from the dispersion curve of the unit cell using the finite element method. The effects of the metamaterial for representative unit cell designs is also calculated for antisymmetric Lamb waves using a transient analysis.

Presenting Author: Kara Peters North Carolina State University

Presenting Author Biography: N/A

Authors:

Waliur Rahman North Carolina State University
Md Raf E Ul Shougat North Carolina State University
Kara Peters North Carolina State University