Notice of Retraction Computational simulation and model analysis on “sweet spot” of bar

In order to find scientific explanation for the empirical finding that the “sweet spot” is not at the end of the bat, computational simulation is applied to the process of the bat-ball collision. The Force Model and the Vibration Model are built respectively to prove the conclusion that “sweet spot” is not at the end of the bat and the conclusion that the baseball bat is just in critically damped situation when the ball hits at the “sweet spot”.