新旧軟式用野球ボールの反発特性

抄録

Since a new rubber baseball ball has been applied in games from 2018, the material properties and the restitution characteristics of the new rubber ball attract plenty of attention among scholars. In this study, the difference of the material properties and the restitution characteristics between the new and old rubber balls is investigated by the static compression and collision tests. In the collision test, the rebound ball speeds of both of the new and the old balls become faster when using a smaller diameter of steel cylinder instead of baseball bat, and the rebound ball speed of the new ball is slower than that of the old one under the same experimental conditions. Furthermore, to develop high performance baseball bats adapting to the new rubber ball, the diameter of the baseball bat is studied by the impacting and batting simulations based on the finite element analysis. From a result of the simulations, the batted ball speed generated by the bat with diameter φ 55 mm is faster than generated by the bat with diameter φ 70 mm.