- Volume 43 Issue 6
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Resonance Frequency Analysis of A Baseball Bat by Impact Angle
가진 각도에 따른 야구배트의 공진주파수 분석
Park, Sun-Hyang;Chung, Woo-Yang;Jung, Hwan-Hee;Lee, Sang-Joon
- Received : 2015.07.21
- Accepted : 2015.09.08
- Published : 2015.11.25
Wood is an anisotropic material that shows the changes in hardness, quality and dimensions depending on the types of cells on three cross sections, size, array and so on. It can also be used in different ways according to its use, which requires a meticulous research, in order to maximize the utilization by understanding the nature and use; and by clarifying the theory and technologies. The research on relationship among wood's physical properties, density, and elasticity of modulus have been studied in Korea and abroad, but those studies were based on correlation gained through standardized specimen. Rather, the study on complete product is rare. Moreover, the previous reports are mostly concentrating on vibration mode and batting, though the wood's physical properties as a material have not been in the main focus. Therefore, this study will carried out for analyzing MOE through figuring material property out and comparing frequency adapting to the Canadian HardMaple bat. For comparison of material properties, we studied the annual ring and density of the bat; calculated the MOE with resonance frequency and formula (ASTM C1259); and verified the repulsive force of this material. As a result, the relevance of the resonance frequency and annual ring is weak, and in comparison in the grain direction in wood, the MOE value is higher when the grain direction in wood is excited horizontally than when is excited vertically, because the material is repulsive when grain direction is horizontal.
Canadian Hardmaple;resonance frequency;modulus of elasticit
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Supported by : 국립산림과학원