S18 基本固有振動数設計を意識したテニスラケットのボールの飛びと打球感に関する性能予測(テニス)

元データ 2005-09-10 社団法人日本機械学会


The lightweight racket with head-heavy configuration is recent tendency of high-tech rackets, increasing power with an increasing racket swing speed. Racket frames as light as 200 grams have appeared in the market. However, the predicted results showed that the lightest racket at present in the market has advantageous for racket head speed, but disadvantageous for coefficient of restitution, rebound power, and post-impact velocity for ground stroke, and it has also large shock vibrations at the racket handle compared to the ordinary super-light weight racket. This means a limit to the weight lightening of tennis racket from the viewpoint of performance. The engineers and racket designers at the racket companies seem to be under intense pressure to keep pumping out new and better technologies every year. Recently a new type of racket designed for improving vibration control appeared in the market. Manufactures says this racket is based on the fundamental (1st) natural frequency design with the same type frame. This paper investigated the physical properties of the two types of racket with the design frequencies of 170 Hz and 150 Hz, predicting the performance in terms of the power and the shock vibrations of player's wrist joint. It is based on the experimental identification of the racket-arm dynamics and the simple nonlinear impact analysis. The result showed that the magnitude of the shock vibrations of racket with the design frequency of 150 Hz at the handle and the wrist joint is smaller particularly at the near side of strings face than that of racket with the design frequency of 170 Hz, while the racket power is almost the same.


川副 嘉彦 埼玉工業大学工学部
川副 嘉彦 埼玉工大
吉成 啓子 白百合女大
友末 亮三 安田女大
吉成 啓子 白百合女子大学
赤石 武章 埼玉工大