Effect of Natural Frequency on Coefficient of Restitution of Table Tennis Racket.

Abstract

Various materials, such as natural wood, plywood, and wood laminate, have been studied for application in table tennis rackets. The performance of each the rackets is evaluated independently by every manufacturing company; however, their performance criterion is unclear owing to their qualitative evaluation. The correlation between the natural frequencies and the coefficient of restitution has already been studied for metal baseball bats. However, this correlation has been barely studied for table tennis rackets. This study conducted natural frequency measurements for several kinds of rackets and investigated the impact of a ball against a racket at different speeds. First, the correlations among the impact velocity, coefficient of restitution, and damage to a ball were investigated by means of colliding the ball against a rigid wall to estimate the characteristics of the ball. Furthermore, the natural frequencies and coefficients of restitution of the rackets were measured using rackets with and without rubber in cantilever state by fixing grip part of the racket. Finally, the effect of natural frequency on the racket's coefficient of restitution was investigated.