Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 2 of 2

Full-Text Articles in Mechanical Engineering

Multi-Modal And Short-Range Transmission Loss In Ice-Covered, Near-Shore Arctic Waters, Miles B. Penhale Jan 2017

Multi-Modal And Short-Range Transmission Loss In Ice-Covered, Near-Shore Arctic Waters, Miles B. Penhale

Dissertations, Master's Theses and Master's Reports

In the past century, extensive research has been done regarding the sound propagation in arctic ice sheets. The majority of this research has focused on low frequency propagation over long distances. One of the most commonly used excitation methods for air-ice-water layers has been explosives. However, environmental regulation has become more stringent, disallowing the use of almost all explosive excitation types. Due to changing climate conditions in these environments, new experimentation is warranted to determine sound propagation characteristics in, through, and under thin ice sheets, in shallow water, over short distances. In April, 2016 several experiments were conducted approximately 2 ...


Voigt, Reuss, Hill, And Self-Consistent Techniques For Modeling Ultrasonic Scattering, Christopher M. Kube, Joseph A. Turner Jan 2015

Voigt, Reuss, Hill, And Self-Consistent Techniques For Modeling Ultrasonic Scattering, Christopher M. Kube, Joseph A. Turner

Mechanical & Materials Engineering Faculty Publications

An elastic wave propagating in a metal loses a portion of its energy from scattering caused by acoustic impedance differences existing at the boundaries of anisotropic grains. Theoretical scattering models capture this phenomena by assuming the incoming wave is described by an average elastic moduli tensorC0ijkl (x) that is perturbed by a grain with elasticityCijkl (x ') where the scattering event occurs when x = x. Previous models have assumed that C0ijkl (x) is the Voigt average of the singlecrystal elastic moduli tensor. However, this assumption may be incorrect because the Voigt average overestimates the ...