抄録
It is known that the presence of a soft stiffness between a baseball and a bat such as the radial compliance of the barrel region of the hollow bat increases the COR. In order to make use of this effect in the case of a rubber-ball baseball, it is obliged to attach a soft material over the barrel actively. Using 3-dimensional finite element analysis system for the impact between the rubber ball and the bat developed by authors, for the bat whose barrel is covered with a sheet of the soft material the effects of Young's modulus, thickness, Poisson's ratio and etc. on the COR are investigated. It is found that a thick material which has the low values of Young's modulus and Poisson's ratio is effective to increase the COR.
