Objective evaluation on performance of billiard cue in hitting ball

Billiards is one of the most fashionable indoor sports around the world. The choice of billiard cues is important for players to win a game. Up to now, the evaluation on the performance of billiard cue almost merely depends on the experience of the famous players, which is subjective and controversial. Aiming at both the objective evaluation and the testing method on the performance of billiard cue, a set of experimental device was designed to measure the dynamic behaviors of both the cue and the ball. Based on theoretical considerations, a force-transferring coefficient is proposed to quantitatively and objectively evaluate the performance of a cue in the efficiency of hitting balls. Both experiments and numerical simulations indicate that those cues with moderate stiffness exhibit the most advantageous force-transferring performance, better than the softer and the harder cues. Moreover, further numerical simulation results indicate that the force-transferring performance of the cue can be enhanced by reducing the anisotropy of the shaft material. For the spinning-ball skills, the rotational velocity of the ball is derived and can be calculated from the ball's translational velocity measured by the device. Experiments showed that a softer tip could make a larger rotating velocity of the ball compared to the harder tip. It is expected that the present work will facilitate the objective and quantitative characterization of the performance of billiard cues, so as to assist players in evaluating and selecting billiard cues. It also offers a technical suggestion for selecting proper row material of cues in order to improve cues’ performance.