A study on support method and restitution characteristic of rubber baseball bat

Abstract

Rubber baseball game using a rubber-ball (made of two types a rubber) is an original and a popular sport in Japan. When the rubber-ball is hit with a baseball bat, the ball is greatly deformed compared to an official baseball ball, and the flying distance of the batted ball decreases due to the energy loss to obtain the ball. In this study, it was elucidated that these phenomena occurring in the rubber-ball during the hitting period using finite element analysis models of ball and bat for a rubber baseball. Also, the validity of the conventional restitution performance evaluation test for the baseball bat was evaluated. The evaluation test is different from the actual baseball game in that the used ball has no spin and the rotation center of bat at the swing. From the hitting simulations, it was found that the influences of the ball spin and the rotation center of the bat on the batted ball speed are not very large. Regarding the batted ball speed, the validity of the conventional evaluation test for baseball bat was confirmed.