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The Design Aspects of Tennis Rackets
Tennis rackets are in a state of continual change. New models are introduced and old models are improved. It is important for anyone with an interest in tennis to understand the modern design aspects of tennis rackets. A person can use this knowledge to improve his or her tennis game and to choose a racket that is best for him or her. Understanding these design aspects is also important to anyone with an interest in modern technology. Today's racket designs rely heavily on the engineering and scientific fields.
This brief describes the current external and internal design aspects of tennis rackets. The external design aspects are strings, head size, and beam size. The internal design aspects are material type, weight, and balance.
External Design Aspects
Strings: The key parts of the performance of the strings are the strings' elongation, tension, and stringing pattern density. The elongation of a string is how much the string's length changes when a force is applied to the string. The string's material and thickness determine its elongation. A string with more elongation provides more power at a given tension, while a string with less elongation provides more control. The tension of the strings is how tightly the racket is strung. Loose strings provide more power. Tight strings "bite" more into the ball and provide better control. The stringing pattern density is the measure of the spacing of the strings on the racket face. If the strings are farther apart, the racket will act as if its tension is lower. If the strings are closer together, the roughness of the plane of the strings is increased. This increased roughness bites the ball more and provides more control.
Head Size: The head size is the size of the racket's face. A longer head provides more power because the racket's region of maximum power is increased, the point where the ball typically hits the string bed is moved to a stiffer part of the frame, and the length of the strings (and, therefore, the elongation of the strings) is increased. A wider head increases the racket's moment of inertia, which provides better control by allowing the racket to better resist the torque created by an off-center hit. Beam Size: The beam size is the width of the racket's cross section. Increasing the beam size increases the racket's stiffness and power.
Internal Design Aspects
Materials: Most modern tennis rackets are made of graphite composites (in which different materials are blended with graphite to obtain a racket with properties that no single material possesses). The newest racket materials self-adjust their stiffness to provide more power on hard shots and more control on soft shots.
Weight and Balance: The balance is the distribution of the racket's weight. Light rackets can be swung faster and provide more power. Heavy rackets transmit less shock and vibration, react less to off-center hits, and provide better control. Head heavy rackets (with most of their weight near the tip) provide more power by placing more weight behind the hit. Head light rackets (with more of it weight in the handle) provide more control because they are more maneuverable and easier to swing.
Table 1 summarizes how the external and internal design aspects can be manipulated to maximize a racket's power and control. This table shows the design trade-offs that must be made to produce a racket with a desired level of power and control.
The Effect of Internal and External Design Aspects
on Racket Power and Control
Feature More Power More Control Strings Elogation Increase Reduce Roughness Increase Reduce Thickness Decrease Increase Tension Decrease Increase Pattern density Decrease Increase Head Size Increase length Increase width Beam Size Increase width N/A Weight Reduce Increase Balance Head Heavy Head Light
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Author's Note: Mr. Vokoun is a senior at the University of Wisconsin at Madison in the Department of Chemical Engineering. He has co-op experience at 3M Corporation. (Back to Beginning)