A New Designed Baseball Bat Based on Sweet Spots

Abstract

This paper describes model testing of a wooden baseball bat with the purpose of finding the peak frequencies and vibration modes and their relation to the so-called “sweet spot”, including the position of the “sweet spot”, the effect of corking a bat and the comparison between wood and metal bats. Present an approach to determining the location of “sweet spot”, which can be classified into three categories: (1) Batter feels the least vibrational sensation. (2) The batted ball is at maximum speed. (3) Maximum energy is transferred to the ball. To analysis the vibration sensation, rotational dynamics model is set. The impulse received by hands varies with different impact positions and form a curve. Through the curve, the “sweet spot” that with least vibrational sensation is found. For maximum batted ball speed, velocity model is set on the basis of the conservation of momentum, regarding the bat as a rigid body. Finally, the curve of batted ball speed of different material and impact position is obtained and the impact point with maximum speed is found. Vibrations involving beam elements model is developed to analysis the maximum energy being transferred. By using beam theory, the “sweet spot” is located. Furthermore, through the three kinds of “sweet spot” this paper designs a new baseball bat that different “sweet spots” gather in a “sweet zone”.