Measurements and calculations are presented on the vibration of the handle of a tennis racquet. It is shown that the vibration amplitude depends primarily on the stiffness of the racquet, but it also depends on the mass of the racquet, the mass distribution, the vibration frequency, the impact location, the impact duration, the stiffness of the ball and the stiffness of the string plane. Mass added at the tip of a racquet usually reduces handle vibrations when the ball impacts near the tip, but it increases handle vibrations for impacts in the throat region. Mass added to the handle usually reduces handle vibrations, regardless of the impact point. Mass added at a vibration node point has no effect on the vibration frequency, only a small effect on amplitude, and can usefully be added to very light and stiff racquets to increase racquet power without affecting the low vibration amplitude of these racquets. The amplitude of the fundamental vibration mode decreases as the impact duration increases, decreasing to zero at all impact points when the impact duration is 1.5 times longer that the fundamental vibration period.
© Copyright 2015 Sports Engineering. The Faculty of Health & Wellbeing, Sheffield Hallam University. Alle Rechte vorbehalten.