Ultrasonic wave propagation in thick, layered composites containing degraded interfaces
Name
63676884-MIT.pdf
Description
Full printable version
Size
4.3 MB
Format
Adobe PDF
Checksum (MD5)
884b35a9689ed6bddcf37d29d08848ae
Author(s)
Small, Peter D. (Peter David)
Advisor(s)
James H. Williams and David V. Burke.
Date Issued
2005
Publisher
Massachusetts Institute of Technology
Abstract
The ultrasonic wave propagation of thick, layered composites containing degraded bonds is investigated. A theoretical one-dimensional model of three attenuative viscoelastic layers containing two imperfect interfaces is introduced. Elastic material properties and measured 'values of ultrasonic phase velocity and attenuation are used to represent E-glass and vinyl ester resin fiber-reinforced plastic (FRP) laminate, syntactic foam, and resin putty materials in the model. The ultrasonic phase velocity in all three materials is shown to be essentially constant in the range of 1.0 to 5.0 megahertz (MHz). The attenuation in all three materials is constant or slightly increasing in the range 1.0 to 3.0 MHz. Numerical simulation of the model via the mass- spring-dashpot lattice model reveals the importance of the input signal shape, wave speed, and layer thickness on obtaining non-overlapping, distinct return signals in pulse-echo ultrasonic nondestructive evaluation. The effect of the interface contact quality on the reflection and transmission coefficients of degraded interfaces is observed in both the simulated and theoretical results.
Description
Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.
Includes bibliographical references.
Subjects
Ocean Engineering.
Mechanical Engineering.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Department of Ocean Engineering
Terms of Use
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.
Persistent DSpace Link
