球拍勁度與網線張力對網球拍恢復係數之影響

Racket Stiffness and Various String Tension Affects the Coefficient of Restitution in Tennis Racket

10.6989/JN.200612.0295

石翔至(Hsiang-Chih Shih)；蘇榮立(Jeon-Li Su)；李秀華(Hsiu-Hua Li)

網球 ； 球拍勁度 ； 網線張力 ； 恢復係數 ； tennis ； racket stiffness ； string tension ； COR

南亞學報

26期（2006 / 12 / 01）

295 - 303

繁體中文

本研究目的在探討不同勁度網球拍與不同網線張力對碰撞後恢復係數的影響。實驗是將將穿好線的不同勁度的網球拍，固定於鉗鋏中，由勁度低的開始依序進行測試，發球機之球速以每秒20m/s射出，調整網球發球機所射出之球與網球拍做正面垂直碰撞，透過Nac高速攝影機（每秒1000張）將整個實驗過程拍攝，影帶經過Peak Performance軟體系統進行數位化處理，將資料分析後，採獨立樣本二因子變異數分析及杜凱式法進行分析。獲得之結論為：1. 勁度較高的網球拍，可獲得較高的恢復係數。2. 穿上50磅的網線比其他網線張力有較高之恢復係數。

The purpose of this study was to investigate the effects of racket stiffness and string tension on the coefficient of restitution (COR) in tennis rackets. In the experimental test, the tennis racket was fixed in a C-clamp and the tennis ball was controlled by the ball shooting machine to hit the racket with a vertical impact at certain speed (approximated as 20 m/sec). NAC high speed camera (1000 frame/sec) was used to record the impact phenomenon. The video tape was digitized using Perk Performance System to get COR, and the data were then analyzed with two-way ANOVA. The result of this study are as follows:1. The higher stiffness of racket will acquire higher COR value.2. The COR value of 50lb string tension racket is significantly higher than those of other string tension rackets.