A Research about Performance of Metal Baseball Bats

To assist in developing a database of wood material properties for the finite element modeling of wood baseball bats, Charpy impact testing at strain rates comparable to those that a wood bat experiences during a bat/ball collision is completed to characterize the failure energy and strain-to-failure as a function of density and slope-of-grain (SoG) for northern white ash (Fraxinus americana) and sugar maple (Acer saccharum). Un-notched Charpy test specimens made from billets of ash and maple that span the range of densities and SoGs that are approved for making professional baseball bats are impacted on either the edge grain or face grain. High-speed video is used to capture each test event and image analysis techniques are used to determine the strain-to-failure for each test. Strain-to-failure as a function of density relations are derived and these relations are used to calculate inputs to the *MAT_WOOD (Material Model 143) and *MAT_EROSION material options in LS-DYNA for the subsequent finite element modeling of the ash and maple Charpy Impact tests and for a maple bat/ball impact. The Charpy test data show that the strain-to-failure increases with increasing density for maple but the strain-to-failure remains essentially constant over the range of densities considered in this study for ash. The flat response of the ash data suggests that ash-bat durability is less sensitive to wood density than maple-bat durability. The available SoG results suggest that density has a greater effect on the impact failure properties of the wood than SoG. However, once the wood begins to fracture, SoG plays a large role in the direction of crack propagation of the wood, thereby determining if the shape of the pieces breaking away from the bat are fairly blunt or spear-like. The finite element modeling results for the Charpy and bat/ball impacts show good correlation with the experimental data.

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High-Speed Impact of Baseball Bats and Balls. 2nd Report, Impact of CFRP Cylinders and Balls.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A ◽

10.1299/kikaia.58.2370 ◽

1992 ◽

Vol 58 (556) ◽

pp. 2370-2374

Author(s):

Koichi TANAKA ◽

Taisuke MASUDA ◽

Hitoshi KODAMA

Keyword(s):

High Speed ◽

High Speed Impact ◽

Baseball Bats

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2205 Mechanical characteristics of aodamo(Fraxmus lanuginosd) as baseball bats

The Proceedings of Design & Systems Conference ◽

10.1299/jsmedsd.2005.15.304 ◽

2005 ◽

Vol 2005.15 (0) ◽

pp. 304-305

Author(s):

Goichi Muto ◽

Akio Koizumi ◽

Takuro Hirai

Keyword(s):

Mechanical Characteristics ◽

Baseball Bats

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Evaluation on hitting performance of baseball bats and their selection according to swing ability of a player

Transactions of the JSME (in Japanese) ◽

10.1299/transjsme.16-00097 ◽

2017 ◽

Vol 83 (846) ◽

pp. 16-00097-16-00097

Author(s):

Hiroyuki KAGAWA ◽

Masaya TAKAHASHI ◽

Kazutaka SATO ◽

Masato MIZOGUCHI ◽

Takeshi YONEYAMA ◽

...

Keyword(s):

Baseball Bats

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Bat Kinematics in Baseball: Implications for Ball Exit Velocity and Player Safety

Journal of Applied Biomechanics ◽

10.1123/jab.19.4.283 ◽

2003 ◽

Vol 19 (4) ◽

pp. 283-294 ◽

Cited By ~ 15

Author(s):

Rochelle L. Nicholls ◽

Bruce C. Elliott ◽

Karol Miller ◽

Michael Koh

Keyword(s):

Horizontal Plane ◽

High Speed ◽

Movement Time ◽

Moment Of Inertia ◽

Moments Of Inertia ◽

Exit Velocity ◽

Safety Issues ◽

Similar Length ◽

Tip Velocity ◽

Baseball Bats

Ball exit velocity (BEV) was measured from 17 experienced baseball hitters using wood and metal bats of similar length and mass but different moments of inertia. This research was conducted in response to safety issues for defensive players related to high BEV from metal baseball bats reported in the literature. Our purpose was to determine whether metal bats, with their lower swing moment of inertia, produce a higher linear bat tip velocity than wooden bats swung by the same players. Analysis using high-speed videography indicated significant differences in the x-component of velocity for both the proximal (metal = 5.4 m s−1; wood = 3.9 m s−1) and distal ends of the bats (metal = 37.2 m s−1; wood = 35.2 m s−1), p < 0.01. The orientation of the bats with respect to the horizontal plane was also significantly more “square” 0.005 s prior to impact (270°) for the metal (264.3°) compared with the wood bat (251.5°), p < 0.01. Mean BEV from metal bats (44.3 m s−1) was higher than the 41 m s−1 velocity which corresponds to the minimum movement time for a pitcher to avoid a ball hit in his direction (Cassidy & Burton, 1989).

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