Publication Date

1992

Document Type

Dissertation/Thesis

First Advisor

Rossing, Thomas D., 1929-

Degree Name

M.S. (Master of Science)

Department

Department of Physics

LCSH

Tennis balls||Rackets (Sporting goods)

Abstract

The vibrational modes of several tennis rackets, including wooden, composite, and wide-body rackets, were determined through the use of impact modal analysis and a single frequency driving/scanning technique. It was observed that the mode frequencies of the rackets made of new composite materials and of a wide-body construction had a higher stiffness than the traditional wooden racket, as well as higher modal damping. The modes were divided into two catagories: one in which the motion was dominated by the frame, and one in which the motion was dominated by the strings. The dwell time and coefficient of restitution (COR) of a tennis ball was measured for three cases: 1) for the ball being dropped onto a hard surface, 2) for the ball being dropped onto the geometric center of the strings of the rackets with their heads clamped, and 3) for the ball being dropped onto the geometric center of the strings of the rackets with their handles firmly clamped. The COR for a new ball on a hard surface was found to be about 0.79, and decreased with increasing impact velocity. The CORs for dropping the ball on the rackets with fixed heads were found to be approximately the same for all of the rackets, in the range 0.90-0.93. For the clamped handle case, the wide-body composite rackets had much higher CORs than the other rackets of about 0.55-0.53.

Comments

Includes bibliographical references (pages [67]-69)

Extent

ix, 86 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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