| Project/Area Number |
07455104
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Dynamics/Control
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
NAKAGAWA Noritoshi Hiroshima University, Department of Engineering, Professor, 工学部, 教授 (80031128)
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| Co-Investigator(Kenkyū-buntansha) |
SEKIGUCHI Yasuhisa Hiroshima University, Research Associate, 工学部, 助手 (60226644)
IKEDA Takashi Hiroshima University, Associate Professor, 工学部, 助教授 (50115523)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥7,100,000 (Direct Cost: ¥7,100,000)
Fiscal Year 1996: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1995: ¥6,400,000 (Direct Cost: ¥6,400,000)
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| Keywords | Impact・Vibration・Sound Characteristics / Collision Mechanism / Sweet-Area / Vibration Energy Flow / Sound Energy Flow / Image Processing / Pure Tone Level / 衝撃特性 / 振動特性 / 音響特性 / 反発速度 |
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| Research Abstract |
The colIision mechanism was investigated by characteristic evaluation of impact, vibration and sound as follows.
1.Experiment and analysis from the viewpoint of characteristic evaluation of impact
The impact deformation of impacted body was measured by the high-speed camera to obtain the deformation characteristics. The restitution coefficient is obtained and the sweet-area which gives the high restitution coefficient was visualized. It was found that the sweet-area exists in the field near the grip part from the center of gravity of the racket.
2.Experiment and analysis from the viewpoint of characteristic evaluation of vibration
The transient vibrations of the system subjected to the impulsive force are analyzed by the wavelet transformation method. It was found the changes of the response spectrum with time depend on the frequency.
3.Experiment and analysis from the viewpoint of characteristic evaluation of sound
To investigate the characteristics of transient sound the changes of spectrum with time for three kinds of sound were analyzed. The sound quality was evaluated by the semantic differential method. The sound quality is discriminated with pure tone level. When the damping of the system becomes large, the vibration energy flow can be estimated with the sound energy flow.
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