Document Type

Thesis - University Access Only

Award Date

1994

Degree Name

Master of Science (MS)

Department / School

Mechanical Engineering

First Advisor

Hamid R. Hamidzadeh

Abstract

Free vibration of three layered sandwich cylinders are considered. The flexural vibration of the main elastic cylinder is damped using viscoelastic core which is discontinuously constrained by number of elastic segments around the circumference. The core layer is assumed to be linear viscoelastic with a complex elastic moduli. In development of analytical procedure the governing V equation for the free vibration of damped system is formulated. As a result a sixth order differential equation for the motion is derived. This equation has the same form as that reported by Mead and Markus for a continuously constrained three layer sandwich beam. Six boundary conditions in terms of flexural displacement are satisfied for fixed-fixed, free-free, and fixed-free discontinuously damped sandwich cylinders. The determinant of coefficient matrix is then equated to zero and roots are computed using iteration method. A parameter study is conducted and dimensionless frequencies and the loss factors are computed for different shear parameter, geometric parameter, and the core loss factor. The ranges of these parameters are sufficient to cover most cases which are encountered in practice for the first three modes of vibration.

Library of Congress Subject Headings

Cylinders -- Vibration -- Mathematical models
Viscoelastic materials
Damping (Mechanics) -- Mathematical models

Format

application/pdf

Publisher

South Dakota State University

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Rights Statement

In Copyright