Finite Element Analysis of Lamb Waves Acting Within a Thin Aluminum Plate

<p>Structural health monitoring (SHM) is an emerging technology that can be used to identify locate and quantify structural damages before failure. Among SHM techniques Lamb waves have become widely used since they can cover large areas from one single location. Due to the development of various structural simulation programs there is increasing interest in whether SHM data obtained from the simulation can be verified by experimentation. The objective of this thesis is to determine Lamb wave responses using SHM models in ABAQUS CAE (a Finite Element Analysis (FEA) program). These results are then compared to experimental results and theoretical predictions under isothermal and thermal gradient conditions in order to assess the sensitivity of piezo-generated Lamb wave propagation. Simulations of isothermal tests are conducted over a temperature range of 0-190-F with 100kHz and 300kHz excitation signal frequencies. The changes in temperature-dependent material properties are correlated to measurable differences in the response signal's waveform and propagation speed.</p><p>This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact and remains as true to the original work as possible. Therefore you will see the original copyright references library stamps (as most of these works have been housed in our most important libraries around the world) and other notations in the work.</p><p>This work is in the public domain in the United States of America and possibly other nations. Within the United States you may freely copy and distribute this work as no entity (individual or corporate) has a copyright on the body of the work.</p><p>As a reproduction of a historical artifact this work may contain missing or blurred pages poor pictures errant marks etc. Scholars believe and we concur that this work is important enough to be preserved reproduced and made generally available to the public. We appreciate your support of the preservation process and thank you for being an important part of keeping this knowledge alive and relevant.</p><br>