Journal article
A determination of the dynamic response of softballs
Sports engineering, Vol.12(4), pp.163-169
08/2010
Handle:
https://hdl.handle.net/2376/114111
Abstract
An apparatus is described for measuring the stiffness and coefficient of restitution (COR) of balls with application to softballs. While standardized test methods currently exist to measure these properties, they do not represent the displacement rate and magnitude that occur in play. The apparatus described herein involves impacting a fixed, solid cylindrical surface (matched to the diameter of the bat) with a ball and measuring the impact force during impact and speed of the ball before and after impact. The ratio of the ball speeds determines the COR, while the impact force is used to derive a ball stiffness. For an example of the contribution of the new ball test, the performance of hollow bats, which is sensitive to ball stiffness, was compared. Bat performance showed a much stronger dependence on the proposed ball stiffness than the traditional measure. Finally, it was shown that to achieve similar conditions between impacts with fixed and recoiling objects, the impact speed should be chosen so that the centre of mass energy was the same in the two cases. The method has application to associations wishing an improved method to regulate ball and bat performance.
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Details
- Title
- A determination of the dynamic response of softballs
- Creators
- Lloyd Smith - School of Mechanical and Materials Engineering Washington State University Pullman WA 99164 USAAlan Nathan - Department of Physics University of Illinois Urbana IL 61801 USAJoseph Duris - School of Mechanical and Materials Engineering Washington State University Pullman WA 99164 USA
- Publication Details
- Sports engineering, Vol.12(4), pp.163-169
- Academic Unit
- Mechanical and Materials Engineering, School of
- Publisher
- Springer-Verlag; London
- Identifiers
- 99900547858601842
- Language
- English
- Resource Type
- Journal article