Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Engineering
3d Acoustic Pipe Locator Imaging Based On Finite Element Analysis, Yi Liu
3d Acoustic Pipe Locator Imaging Based On Finite Element Analysis, Yi Liu
Graduate College Dissertations and Theses
A more complex underground pipe system is growing with the expansion of cities. However, there is no comprehensive database of underground pipes. Thus, it is urgent to build database with materials, positions, diameters, and etc. To locate the pipes is the first step. There are many ways to find pipes such as metal detector, ground penetrating radar, and acoustic method. Metal detectors are becoming increasing ineffective with more and more nonmetal is using in pipes. Ground penetrating radar is a precise way to find pipes but it is only works well under low moisture environment. Additionally, ground penetrating radar is …
Nonlinear Ball Chain Waveguides For Acoustic Emission And Ultrasound Sensing Of Ablation, Stephen Herbert Pearson
Nonlinear Ball Chain Waveguides For Acoustic Emission And Ultrasound Sensing Of Ablation, Stephen Herbert Pearson
Graduate College Dissertations and Theses
Harsh environment acoustic emission and ultrasonic wave sensing applications often benefit from placing the sensor in a remote and more benign physical location by using waveguides to transmit elastic waves between the structural location under test and the transducer. Waveguides are normally designed to have high fidelity over broad frequency ranges to minimize distortion - often difficult to achieve in practice. This thesis reports on an examination of using nonlinear ball chain waveguides for the transmission of acoustic emission and ultrasonic waves for the monitoring of thermal protection systems undergoing severe heat loading, leading to ablation and similar processes. Experiments …